Goldschmidt 2012 Conference Abstracts Tracing crustal contamination along Multi-scale modeling of transverse the Java segment of Sunda Arc, reactive mixing in a coastal aquifer 1,3* 1 1,2 Indonesia H. M. NICK , A. RAOOF , M. THULLNER , P.A.G. REGNIER3 JOLIS, E. M.1*, TROLL, V. R.1, 4, DEEGAN, F. M. 2, 1Faculty of Geosciences, Utrecht University, Utrecht, The BLYTHE, L. S. 1, HARRIS, C.3, FREDA, C. 4, HILTON, D. 5, Netherlands (*correspondence: [email protected], [email protected]) 6 6 CHADWICK, J. , VAN HELDEN, M. 2Department of Environmental Microbiology, UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany 1 Dept. Earth Sciences, CEMPEG, Uppsala, Sweden ([email protected]) (*[email protected]) 3Department of Earth and Environmental Sciences, Université Libre 2 Lab. for Isotope Geology, SMNH, Stockhom, Sweden de Bruxelles, Brussels, Belgium ([email protected]) 3 Dept. of Geological Science, UCT, South Africa 4 Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy The transverse mixing between freshwater and seawater in 5 Scripps Oceanographic Institute, San Diego, USA 6 Dept. Petrology, Vrije, Universiteit Amsterdam, Netherlands coastal aquifers is a key process controlling the chemistry of submarine groundwater discharge (SGD). The quantification of such Arc magmas typically display chemical and petrographic mixing and its effects on the fate of reactive chemical compounds in characteristics indicative of crustal input. Crustal contamination can take place either in the mantle source region or as magma coastal waters are still the subject of debate. We developed reactive traverses the crust (e.g. [1]). While source contamination is transport model approaches to study the mechanisms responsible for generally considered the dominant process (e.g. [2, 3, 4]), crustal contamination in high level magma chambers has also controlling reactive mixing processes in coastal aquifers. These been recognised at volcanic arcs (e.g. [5, 6]). In light of this, we models employ hybrid numerical methods for solving flow and aim to test the extent of upper crustal versus source contamination along the Java segment of the Sunda arc, which, transport [1,2], and benefit from utilizing the biogeochemical because of its variable upper crustal structure, is ideal for the reaction network simulator (BRNS) [3]. task. We present a detailed geochemical study of 7 volcanoes Critical to advancing our understanding is the study of the along a traverse from Anak-Krakatau in the Sunda strait interplay between reaction and flow. We particularly investigated the through Java (Gede, Slamet, Merapi, Kelut, Kawah-Ijen) and Bali (Batur). Using rock and mineral elemental geochemistry impact of dispersion, heterogeneity induced velocity variations and and radiogenic (Sr, Nd and Pb) and, stable (O) isotopes, we show a correspondence between changes in composition of the biogeochemical reactivities on reactive transport for density driven upper crust and the apparent degree of upper crustal flow scenarios representing seawater-groundwater-interface in contamination. There is an increase in 87Sr/86Sr and δ18O, and a decrease in 143Nd/144Nd from Krakatau towards Merapi, coastal aquifers. Our numerical observation showed e.g., that for indicating substantial input from the thick quasi-continental highly reactive dissolved organic carbon (DOC) degradation basement beneath East and Central Java. Volcanoes to the east of Merapi, and the Progo-Muria fault zone, where the upper processes are limited by the porous media properties controlling crust is thinner and increasingly oceanic in nature have lower dispersion, whereas for relatively less reactive DOC degradation is 87Sr/86Sr and δ18O, and higher 143Nd/144Nd indicating a stronger influence of the mantle source [7]. Our new data represent a controlled by reaction kinetics. systematic and high-resolution arc-wide sampling effort that In general, we found three reactive flow regimes: reaction allows us to distinguish the effects of the upper crust on the compositional spectrum of individual volcanic systems along controlled, reaction-dispersion controlled and dispersion the Sunda arc. controlled transport. This is supported by further simulations

utilizing pore-scale models to investigate these regimes at the

[1] Davidson, J.P, Hora, J.M, Garrison, J.M & Dungan, M.A smaller scale. Our results suggest that the chemical reactivity as (2005), J. Geotherm. Res., 140, 157-170. well as dispersivity are important parameters governing the [2] Hilton, D.R., Fischer, T.P. & Marty, B. (2002), Rev. Mineral. Geochem., 47, 319-370. biogeochemical dynamics of SGD. Hence, an adequate [3] Gertisser, R. & Keller, J. (2003). J. Petrol., 44, 457-489 representenation of these processes in the macro-scale models is [4] Debaille, V., Doucelance, R., Weis, D., & Schiano, P. (2005), Geochim. Cosmochim. Acta, 70,723-741. essential. [5] Gasparon, M., Hilton, D.R., & Varne, R. (1994), Earth Planet. Sci. Lett., 126, 15-22. [1] S.K. Matthai, et al. (2009) Transport in Porous Media 83, 289- [6] Chadwick, J.P., Troll, V.R., Ginibre, C., Morgan, D., 318. Gertisser, R., Waight, T.E. & Davidson, J.P. (2007), J. Petrol., [2] A. Raoof, et al. (2010) Vadose Zone Journal 9, 624-636. 48, 1793-1812. [3] P. Regnier, et al. (2002) Applied Mathematical Modeling 26, [7] Whitford, D.J. (1975), Geochim. Cosmochim. Acta, 39, 913-927. 1287-1302.

Mineralogical Magazine | www.minersoc.org 2045 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Mantle Evolution from Plate Heterogeneous mantle sources of the Subduction to Post-orogenic alkaline-tholeiitic intraplate basalts Extension: Evidence from Permo- from the Aleppo Plateau, NW Syria 1,2* 2 3 Triassic Mafic Dike Swarms in GEORGE S.-K. MA , JOHN MALPAS , KATSUHIKO SUZUKI , 4 1 1 Northern Tibet Plateau CHING-HUA LO , KUO-LUNG WANG , YOSHIYUKI IIZUKA 2 AND COSTAS XENOPHONTOS CHANGQIAN MA1,2*, JINYANG ZHANG2, FUHAO 1IES, Academia Sinica, Taipei 11529, Taiwan, 2 2 2 2 XIONG , BIN LIU , JIAN HUANG AND BAIHUA WANG [email protected] 1 State Key Lab. of Geological Processes and Mineral Resources, 2Department of Earth Sciences, The University of Hong Kong, Hong

Wuhan, China, [email protected] (* presenting author) Kong 3IFREE, JAMSTEC, Japan 2 China University of Geosciences,Wuhan,China 4Department of Geosciences, National Taiwan University, Taiwan Five large mafic dike swarms have been discovered within the ~270 km-long Xiangride-Golmud segment of the East Kunlun belt, Mantle-derived magmas are characterised by considerable chemical and isotopic variability that is difficult to reconcile with Northern Tibet Plateau, which are named, from east to west, the partial melting of a peridotite mantle alone. This reflects the Balong, Binggou, Xiaomiao, Bairiqili and Nanshankou dyke swarms. presence of heterogeneities in the mantle, originated from, for The number of dikes in a given swarm can vary from 10 to 42, and instance, recycled oceanic crust or metasomatised lithosphere [1, 2, the width of individual dikes ranges from 0.1 to 5 m. Most of the 3]. Identification of such heterogeneities and thus the mineralogy of the mantle source becomes more ambiguous because both crustal dikes trend N-S. The widest dikes are clearly banded with coarser contamination and crystal fractionation may mask important source textures and more phenocrysts in the middle portions than in the characteristics. margins. Most of the dikes are porphyritic diabase with the coarser- We present age, chemical and isotopic data to constrain the grained varieties grading into diorites. All of the mafic dikes are source and the chemical evolution of the continental alkaline- composed chiefly of clinopyroxene, plagioclase and amphibole. tholeiitic intraplate magmas from the Aleppo Plateau and vicinity, NW Syria. With the aid of new 40Ar/ 39Ar ages, two phases of Based on the field relationships, hornblende Ar-Ar and zircon volcanism have been recognised in the Miocene, ~19-18 Ma (Phase U-Pb dating we consider that the dike swams were formed in three 1) and ~13.5-12 Ma (Phase 2), in the studied area. The chemical and 87 86 143 144 episodes; Early Permian, late Permian and Triassic to Late Triassic. isotopic compositions [ Sr/ Sr = 0.7036-0.7051, Nd/ Nd = 0.51269-0.51287 and (187Os/188Os) = 0.151-0.453] of the lavas The Xiaomiao (277 Ma) and Binggou (225 Ma) mafic dikes are t reflect the unequivocal influence of crustal assimilation and calc-alkaline in composition with low ∑REE (˘100 ppm) and fractional crystallisation. However, it is interpreted that the two relatively flat, chondrite-normalized REE patterns with no Eu phases of volcanism likely sampled a mineralogically heterogeneous anomalies. These rocks also have low Ni, Cr and V but are enriched source, as reflected by their compositional variations seen in the in Rb, K, Pb and P, and depleted in Nb and Ta. In contrast, the Balong most-primitive, least contaminated magmas. Such variations are: (1) relatively high Si, low Ti and trace-element contents in the Phase 1 dike swarms (253 Ma) have high ∑REE (~100 to >150 ppm˅and lavas, consistent with partial melting of a largely peridotitic mantle are enriched in HREE, with higher trace element contents than the source; (2) relatively low Si, high Ti, Fe, Ca, P, alkalis, and L- other dikes. The Xiaomiao and Binggou dike swarms have similar MREE/HREE, plus sub-chondritic Th-(U)/Nb, Pb/Ce and Zr/Sm in Sr-Nd isotopic characteristics with ISr = 0.707-0.711 and εNd(t) the Phase 2 lavas, approaching compositions of experimental melts ranges from -3.4 to 3.9, whereas the Bairiqili (251 Ma) and Balong of amphibole-rich metasomatic veins [3]. Thus, it is inferred that the Syrian lithosphere had been pervasively metasomatised and dikes have somewhat more enriched and variable compositions, with contained veins of amphibole-rich cumulates shortly before ISr = 0.709-0.719 and εNd(t) ranging from -7.8 to -3.6. The volcanism, and that the changing compositions of the Phase 1 to geochemical similarities of the Permin –Triassic East Kunlun, South Phase 2 lavas (increasing Si-undersaturation) reflected an increasing Qiangtang and north Himalaya dike swarms and basalts indicate that contribution from the metasomatic vein-derived melts.

the north boundary of Gondwana reached the East Kunlun block at

that time. [1] Hofmann (1997) Nature 385, 219-229. [2] Jackson & Dasgupta Further study of these dike swarms should lead to a better (2008) EPSL 276, 175-186. [3] Pilet et al. (2008) Science 320, 916-919. understanding of the influence of subducted slabs on the mantle source and subduction mechanics during the evolutionary stage between the Paleo-Tethyan oceanic plate subduction and post- orogenic extension.

Mineralogical Magazine | www.minersoc.org 2046 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Using Uranium Isotopes to Determine Petrogenesis of the Aolunhua igneous Salinity Sources in Rio Grande complex, eastern Central Asian Waters Orogenic Belt: Geochemical, and Sr– 1* 1 1 LIN MA , ANNA SZYNKIEWICZ , DAVID BORROK , AND Nd–Hf isotopic constraints 2 JENNIFER C. MCINTOSH 1* 1,2 1 XINGHUA MA , BIN CHEN , AND ZHIQIANG WANG 1Department of Geological Sciences, University of Texas at El Paso, 1Key Laboratory of Orogenic Belts and Crustal Evolution, Peking El Paso, TX 79968, USA, [email protected] (* presenting author), University, Beijing 100871, China, [email protected], [email protected] [email protected] (* presenting author) 2Department of Hydrology and Water Resources, University of 2Institute of Geology and Exploration Engineering, Xinjiang Arizona, Tucson, AZ 85721, USA, [email protected] University, Urumchi 830046, China,

[email protected] Abstract The Rio Grande flows from Southern Colorado through New A large-scale Early Cretaceous magmatic-metallogenic belt Mexico and West Texas down to the Gulf of Mexico. It serves as an (known as the Xar moron belt) has recently been recognized in the important water supply for agricutural and municipal needs. In Rio eastern Central Asian Orogenic Belt (CAOB), but the process and Grande waters, total dissolved solids (TDS) increase from ~40 mg/L mechanism for the formation of this belt are controversial. Here we at the headwaters to 500-1500 mg/L at El Paso, Texas. The elevated report geochemical and Sr–Nd–Hf isotopic data for the Aolunhua TDS values in downstream water cause various problems such as igneous complex (genetically related to a porphyry-type Mo reduction in crop productivity and deterioration of soil quality due deposit), to reveal its petrogenesis, source nature, and implications to salt loading. A number of natural and anthropogenic factors may for the Mesozoic tectonic evolution of eastern CAOB. lead to increased salinity, so the exact sources and their relative The complex consists of a batholith (monzogranite-porphyry) 234 contributions to the salt load remain unclear. U isotopes (e.g., U and late-stage bimodal dyke swarms (quartz-porphyry and diorite 238 and U) fractionate naturally when released from rocks to waters dykes). Geochemically, the monzogranite-porphyry exhibits features during chemical weathering processes at Earth’s surface. It has been of arc rocks such as conspicuous Nb, Ta negative anomalies and suggested that the degree of U isotope fractionation depends largely LILE enrichment (e.g., Sr and Ba). It has low Isr, positive εNd(t) values on local lithology and climate conditions, which affect chemical of +0.5 to +1.4 and εHf(t) values of +3.5 to +9.8. These features, weathering and U release rates. U isotopes in natural waters thus together with young inherited zircons (< 360 Ma) from the source have great potential to serve as natural tracers for chemical region, suggest a juvenile basement dominated by the late Paleozoic weathering processes, which in turn can help to determine the island-arc series. The mafic enclaves hosted in the monzogranite- origins of dissolved solids (i.e., salts) and their history. porphyry are characterized by containing H2O-bearing minerals (e.g., Here, we measured the U concentrations and isotope ratios for Hb and Bi) and more calcic plagioclases, variable elements water samples collected along a ~ 1000 km stretch of Rio Grande compositions, high Mg#, enrichment of Sr and LREE, and radiogenic (from the headwaters in Colorado to El Paso, Texas), as well as from Nd-Hf isotopic compositions (εNd(t) = +0.7 to +1.6 and εHf(t) = streams and springs in the Jemez Mountains, a small drainage basin +3.3 to +10.9), indicating that they originated from a subduction- that recharges to Rio Grande in northern New Mexico. The modified mantle, followed by a significant fractionation of comparison of these two case studies reveals different evolution ferromagnesian phases such as pyroxene and hornblende. histories for U in surface waters. In the Jemez Mountain region Petrological and geochemical evidences including hornblende- where human impacts are minimal, U isotope ratios in surface rimmed quartz ocelli, pervasive acicular apatites in mafic enclaves, waters are largely controlled by rhyolite weathering, and both U compositional disequilibrium in plagioclases and high Mg# features 234 238 concentrations (0.01-0.19 ppb) and ( U/ U) activity ratios (1.5- of the host rocks, demonstrate that mixing between mantle magma 3.0) vary systematically with elevation (2600-2900 m). Here, and crustal melts have played an important role in the formation of solutes in streams largely represent mixing of two sources: young monzogranite-porphyry. The quartz-porphyry dykes show high SiO2 surface water (e.g., several months old) with low U concentrations concentrations, low Mg#, conspicuous negative Eu anomalies and 234 238 and high ( U/ U) ratios and relatively old shallow groundwater relatively flat REE patterns. The contemporaneous diorite dykes, 234 238 that has higher U concentrations and lower ( U/ U) ratios. however, show geochemical and isotopic characteristics similar to 234 238 Similar ranges of U concentrations and ( U/ U) ratios are the mafic enclaves. The two kinds of dykes probably have been observed for the headwater regions of the Rio Grande. U originated from melting of lower crust and mantle source, concentrations in the Rio Grande increase significantly downstream respectively, in a late stage when the monzogranite-porphyry 2+ 2+ - (0.12 to 5.97 ppb) and correlate well with Ca , Mg , and HCO3 batholiths was solidified. ions, revealing a control of carbonate dissolution/precipitation on In summary, the Aolunhua igneous complex formed due to the river water chemistry. This is probaly due to a change of lithology. In reactivation of the juvenile CAOB in the Early Cretaceous when the 234 238 addition, both ( U/ U) ratios (1.6-2.1) and U concentrations in Paleo-Pacific oceanic slab subducted beneath eastern China, and the Rio Grande waters show strong seasonal patterns, reflecting the triggered the upwelling of asthenosphere, which resulted in human impacts on river chemistry, such as the regulation of river lithospheric thinning and extensive magmatism in the eastern CAOB. flows by reservoirs and dams, agricultural irrigation return flows, and pumping of cold/geothermal aquifer waters.

Mineralogical Magazine | www.minersoc.org 2047 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Investigations into temporal and Metagenome-enabled investigation of spatial variations in atmospheric microbial sulfur precipitation in a helium isotopes carbonate aquifer

1* 1 1 1* 1 J.C. MABRY , B. MARTY , P. BURNARD JENNIFER L. MACALADY , DANIEL S. JONES , IRENE 1 2 2 SCHAPERDOTH , CLARA CHAN AND KEVIN CABANISS 1CRPG-CNRS, 54501 Nancy, France (*correspondence: [email protected]) 1Penn State University, Geosciences Dept., University Park, PA, USA (*presenting author, [email protected]) This work describes the development of a method to measure 2Univ of Delaware, Earth, Ocean & Environment, Newark, DE, USA atmospheric helium isotopes at a very high precision (0.2% or better). The primary motivation is to look for potential temporal or Microbial coupling between carbon and sulfur elemental cycles spatial variations in the helium isotopic composition of the in iron-poor, carbonate-rich environments results in the dissolution atmosphere. Since crustal helium has a large excess of 4He relative of carbonate minerals, precipitation of gypsum, and/or the to atmospheric helium, recent anthropogenic activities such as fossil precipiation and dissolution of elemental S. In particular, the fuel exploitation may give rise to a change in the atmospheric incomplete oxidation of sulfide to elemental S strongly affects the composition [1, 2]. However, previous measurements have put an availability of H2S and H2SO4, acids which contribute to limestone upper limit on this near current measurement abilities [3, 4]. There dissolution. The sulfidic Frasassi caves provide a superb model are significant analytical challenges to improving the precision of environment for understanding biotic and abiotic controls on the atmospheric helium measurments as helium is only present in trace balance of these processes, which affect porosity development and quantities in the air (5.24 ppm) and there are are many of orders of fluid flow in sedimentary aquifers and the diagenesis of marine magnitude difference in the abundance of the two isotopes carbonates. 3 4 -6 ( He/ Heair = 1.38 ×10 ). In the Frasassi system, four types of sulfide-oxidizing biofilm To improve our ability to measure helium isotopes precisely, communities develop in separate niches defined by dissolved we have constructed an automated extraction line which can rapidly sulfide:oxygen ratios and hydrodynamic shear [1]. Elemental switch between measuring aliquots of sample with standards. For analyses suggest that S precipitates most rapidly in locations where each measurement we purify a relatively large amount of gas (~20 turbulent mixing brings sulfidic water in contact with cave air, cm3) so that we can make many repeat analyses of the same sample resulting in biofilms that are 40-80% sulfur by mass. Major gas. A major component of our method features an adjustable populations in the biofilms include members of widely-dispersed bellows on the sample aliquot volume that enables us to adjust the and uncultivated sulfur-oxidizing clades, including size of a sample aliquot to precisely match the standard, eliminating Gammaproteobacteria related to "Thiobacillus baregensis" (Tbar) and biases arising from nonlinear pressure effects in the mass Sulfurovumales-group Epsilonproteobacteria. Based on FISH spectrometer. population counts with genus and group-specific probes, Prior to analysis we remove the neon (and any other gases Sulfurovumales are successful only when the sulfide:oxygen ratio remaining after purification) with a cryo trap. This lowers the exceeds 150. In contrast, Tbar populations are not correlated with pressure in the mass spectrometer and makes it easier to be sure that concentrations of sulfide, oxygen, or the dissolved sulfide:oxygen the standard and sample aliquots are the same size. There is an ratio. additional cryo trap on the mass spectrometer volume to maintain To further investigate the geochemical and ecological factors low background levels. Adding the cryo trap reduced the statistical that favor the growth of Tbar and Sulfurovumales populations, and errors of repeated standard analysis within one day from 0.5% to implications for sulfur precipitation and limestone dissolution, we 0.3% (2σ). Meanwhile the absolute scatter of measurements over investigated the metabolic capabilities of the sulfur-precipitating several days fell from ~5% before the addition of the cryo trap to biofilms using enrichment culturing and metagenomics. Initial better than 0.5%. We believe much of this remaining scatter can be enrichment culturing efforts suggest that Tbar and Sulfurovumales attributed to an instability discovered in the high voltage power populations are autotrophic or mixotrophic, and that batch (rather supply of the source. than flow-through) culturing methods favor the growth of Tbar over All of the previous measurements were made on a GV Sulfurovumales. Four metagenomes derived from biofilms naturally Instruments Helix split flight tube multi-collector mass enriched in Tbar and Sulfurovumales populations are currently in spectrometer, which was specifically designed for helium isotope production, and will provide genetic clues necessary to enhance measurements. Future measurements will be made on a new version enrichment culturing efforts and constrain the metabolic potential of of the same machine built by Thermo Scientific and recently these ecologically successful groups, including pathways for partial installed in our lab (January 2012). The new machine has already or complete S oxidation, S reduction, C and N fixation, demonstrated approximately three times higher sensitivity as well as heterotrophy, and biofilm formation. better electronic stability. First results with the new machine will be presented at the conference. [1] Oliver et al. (1984) GCA 48, 1759-1767. [2] Pierson- [1] Macalady (2008) ISME Journal 2, 590-601. Wickman et al. (2001) EPSL 194, 165-175. [3] Sano et al. (2010) GCA 74, 4893-4901. [4] Lupton and Evans (2004) GRL 31, L13101.

Mineralogical Magazine | www.minersoc.org 2048 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Isotopic and mineralogical properties In Situ Determination of Sulfide of surface sediment from the circum Oxidation Rates in the Green Sulfur Arctic Bacterium Chlorobaculum tepidum

1* 1 1* 1 1 JENNY MACCALI , CLAUDE HILLAIRE-MARCEL Daniel J. MacDonald , Alyssa Findlay , Kevin Shuman , 1 1 1 1 Daniel Hess , Thomas E. Hanson , and George W. Luther GEOTOP-UQAM, Montréal, Canada, [email protected] (* presenting author) 1College of Earth, Ocean, and Environment, University of Delaware, Lewes, DE 19958

*[email protected] Radiogenic isotopes (RI) have been used to trace sediment origin in various ocean basins [1, 2, 3, 4, 5, 6]. This method is Sulfur cycling in many environments is regulated by particularly useful in sites where ire-rafting deposition (IRD) microbial activity. As the most reduced form of sulfur, H2S, is toxic represents an important sediment transport mechanism, as illustrated to many aerobic organisms; however, Chlorobaculum tepidum uses recently by RI-analyses in cored sediments from Fram Strait [7], the sulfide as an electron donor during photosynthesis. Microbial main sea-ice exit pathway from the Arctic Ocean towards the North sulfide oxidation is a major sulfide removal mechanism, yet the relevant microbial oxidation rates are relatively unknown. In a Atlantic. Mineral-lattice bound Pb-, Sr- and Nd- isotopes (i.e., linked recent study biological sulfide oxidation rates were determined to to detrital sediment supplies) from this sedimentary sequence exceed abiotic oxidation rates by several orders of magnitude1. displayed two distinct temporal trends since the Last glacial Voltammetric data will be presented that examines the rate of Maximum [7]. In this study, three main detrital supply areas were sulfide loss due to microbial uptake and oxidation over a variety of defined, based on literature data, respectively, the Canadian and physical and biochemical parameters, such as the effects of light Russian margins, and northern Greenland. Broad sea-ice intensity, biomass concentration and total sulfide concentration. Speciation of sulfide oxidation products, such as elemental sulfur paleocirculation patterns were then proposed based on the Fram and polysulfides, and the rates at which these products form, will be Strait RI-record. In order to refine sea-ice paleo-circulation presented. Initial data show that these organisms follow Michaelis- reconstructions, we have undertaken a more detailed survey of Menten kinetics with an approximate apparent saturation rate of 100 potential circum-Arctic sediment sources, using surface-sediment PM sulfide. samples from the Canadian Arctic Archipelago, the Beaufort Shelf, Bering Strait, the Chukchi Sea, the East Siberian, Laptev, Kara and Barents seas. Nd- and Sr- isotope data now define more detailed isotopic domains with, for instance, low epsilon Nd values corresponding to North American cratons, and high epsilon Nd [1] Luther et. al. (2011) “Thermodynamics and Kinetics of sulfide values linked to Pacific inputs through Bering Strait. These domains oxidation by oxygen: a look at inorganically controlled reactions are compared with relevent mineralogical information (e.g. iron- and biologically mediated processes in the environment” oxides) from Darby [8]. This ‘RI-mapping’ data set should improve Frontiers in Microbiology. 2. quantitative estimates of IRD sources and mixing in sedimentary records from the Arctic, thus of the dynamics of surrounding continental ice-margins during the Quaternary.

[1] Fagel et al. (2004) Paleoceanography 19, 1-16. [2] Frank et al. (2002) Reviews of Geophysics 40, 1-38. [3] Haley et al. (2008) Paleoceanography 23. [4] Tütken et al. (2002) Marine Geology 182, 351-372. [5] Winter et al. (1997) Geochimica and Cosmochimica Acta 19, 4181-4200. [6] O’Nions et al. (1978) Nature 273, 435-438. [7] Maccali et al. (2012) Paleoceanography 27. [8] Darby (2003) Journal of Geophysical Research: Oceans 108, 13-1.

Mineralogical Magazine | www.minersoc.org 2049 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Natural-abundance stable Surface complexation modeling of carbon isotopes of small-subunit Na+ and Rb+ adsorption by rutile to ribosomal RNA (SSU rRNA): 250oC 1 2 first results from Guaymas MICHAEL L. MACHESKY *, MILAN PŘEDOTA , MOIRA K. 3 4 Basin (Mexico) RIDLEY , AND DAVID J. WESOLOWSKI 1Univ. of Illinois, Illinois State Water Survey, Champaign IL, USA, BARBARA J. MACGREGOR*, HOWARD MENDLOVITZ, [email protected] (* presenting author) DANIEL ALBERT, AND ANDREAS P. TESKE 2Univ. South Bohemia, České Budějovice, Czech Republic,

University of North Carolina, Dept. of Marine Sciences [email protected] 3 *[email protected], [email protected], Texas Tech Univ., Dept. of Geosciences, Lubbock, TX, USA, [email protected], [email protected] [email protected] 4Oak Ridge National Laboratory, Oak Ridge, TN, USA, Introduction [email protected] Small-subunit ribosomal RNA (SSU rRNA) is a phylogenetically informative molecule found in all cells. Being poorly preserved in most environments, it is a useful Surface complexation models (SCMs) provide the means to marker for active microbial populations. At Guaymas Basin, rationalize and extend (to uncharacterized conditions) cation hydrothermal fluids interact with abundant sedimentary adsorption data, and increasing use is being made of molecular level organic carbon to produce natural gas and petroleum. Where experimental and/or modeling results to constrain SCM parameter this reaches the sediment surface, it can support dense space. One rather surprising finding of this molecular-level patches of seafloor life, including Beggiatoa mats. We report here on the stable carbon isotopic composition of SSU rRNA information is that monovalent alkali metal cations can bind in inner- from a Beggiatoa mat transect, a cold background site, and a sphere fashion to oxides such as rutile. Given the very common use warm site with high oil concentration. Our initial hypotheses of alkali metal salts as background electrolyte media for adsorption were that rRNA isotopic composition would be strongly experiments, it therefore becomes necessary to incorporate inner- influenced by methane supply, and that archaeal rRNA might sphere adsorption of alkali metal cations into SCMs to best be lighter than bacterial due to contributions from methanogens and anaerobic methane oxidizers. represent molecular-level reality. Ridley et al [1] demonstrated that the CD-MUSIC model of Results and Conclusion Hiemstra, van Riemsdijk and co-workers can successfully The central part of the mat overlay the steepest temperature accommodate inner-sphere binding of Na+, K+, and Rb+, as gleaned gradient, and was visually dominated by orange Beggiatoa. from ab initio constrained classical molecular dynamics (CMD) This was fringed by white Beggiatoa mat and bare, but still + + simulations (for Na , Rb ) and X-ray reflectivity measurements (for warm, sediment. Methane concentrations were saturating + o beneath the mat and at the oily site, lower beneath bare Rb ) in fitting 25 C rutile surface titration data. We have extended sediment, and below detection at the background site. this CD-MUSIC approach to rutile surface titration data collected to 250oC in NaCl, NaTr(Tr=triflate) and RbCl electrolyte solutions. CMD results that track Na+ and Rb+ adsorption by the 110 surface of rutile at 25, 150, and 250oC and several charge states are used to constrain the allowable CD-MUSIC model parameters and it is shown that the resulting SCM can adequately mirror most of the CMD results over the broad ambient to hydrothermal temperature range. Figure 1. Stable carbon isotope composition of rRNA captured by magnetic bead capture hybridization [1].

We used biotin-labeled oligonucleotides to capture [1] Ridley et al. (2009) Geochim. Cosmochim. Acta 73, 1841-1856. Bacterial and Archaeal SSU rRNA for isotopic determination (Fig. 1). Background-site rRNA was isotopically heaviest, and bacterial RNA from below 2 cm at the oily site was lightest, consistent with control by methane. Within the mat, however, rRNA from the bare periphery was lightest. There was no consistent isotopic difference between the probes, although RNA recoveries were too low for capture at depths where methanogens and methane oxidizers are expected. Our prediction that rRNA isotopes would correlate directly with methane supply was clearly oversimplified. Future work will include the isotopic characterization of other potential carbon substrates. We are also investigating Gulf of Mexico sediments, where methane is significantly more 13C-depleted than at Guaymas Basin.

[1] Miyatake et al. (2009) Appl. Environ. Microbiol. 75, 4927-4935.

Mineralogical Magazine | www.minersoc.org 2050 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Discharge-driven harmful algal Nanodiamonds and carbonaceous blooms in the NE Gulf of Mexico grains in Bull Creek Valley, 1* 2 2 H.L. MACINTYRE , J.D. LIEFER , L. NOVOVESKA , W.C. Oklahoma 3 3 3 4 4 BURNETT , N. SU , K.T. ELLER , W.L. SMITH , C.P. DORSEY , 1* 1 5 5 ANDREW S. MADDEN , ANDREW L. SWINDLE , LELAND C. R.H. PETERSON AND R.F. VISO 2 3 4 BEMENT , BRIAN J. CARTER , ALEX R. SIMMS , AND MOURAD 5 1Dalhousie University, Halifax, Canada, [email protected] (* BENAMARA presenting author) 1University of Oklahoma, Norman OK, USA, [email protected] (* 2Dauphin Island Sea Lab, Dauphin Island, USA, presenting author), [email protected] [email protected], [email protected] 2Oklahoma Archaeological Survey, Norman OK, USA, 3Florida State University, Tallahassee, USA, [email protected], [email protected] [email protected], [email protected] 3Oklahoma State University, Stillwater OK, USA, 4Alabama Department of Public Health, Mobile, USA, [email protected] [email protected], [email protected] 4University of California Santa Barbara, Santa Barbara CA, USA, 5Coastal Carolina University, Conway, USA, [email protected], [email protected] [email protected] 5University of Arkansas, Fayetteville AR, USA, [email protected]

The state of Alabama (USA) has only 100 km of coastline

but has had recurring harmful algal blooms (HABs) at two shallow- Sediments in the Bull Creek Valley document the Pliestocene- water hot-spots. Both are in the same hydrological unit on the Holocene transition, including the period corresponding to the eastern margin of Mobile Bay. The first, Weeks Bay, is a sub-estuary Younger Dryas climate anomaly. Conflicting reports of on the eastern margin of Mobile Bay and is the site of diverse nanodiamond presence/ absence, spatial/ temporal distribution, and dinoflagellate blooms that cause hypoxia and fish-kills. The second, polymorphic phase identification [e.g., 1,2] are perhaps not the Gulf of Mexico shoreline adjacent to Little Lagoon, a shallow surprising given the challenges of recovering and identifying such and saline lagoon, is the site of toxic blooms of the diatom Pseudo- materials within bulk sediments. Nanodiamonds form nitzschia spp. Initiation of both dinoflagellate and diatom blooms is extraterrestrially; their distribution in Earth sediments may relate to correlated with discharge from the aquifer. the intensity of extraterrestrial bombardment. It has been suggested Microalgal community composition appears to be driven by that a nanodiamond spike in Younger Dryas strata records an impact the interaction of temperature and submarine groundwater discharge. event, contributing to cooling on a global to regional scale [1]. Dinoflagellates bloom in Weeks Bay during periods of low For this study, sediments corresponding to alluvial, paleosol, discharge in both winter (Prorocentrum minimum) and summer and loess horizons were collected from multiple profiles across the (Karlodinium veneficum). Pseudo-nitzschia spp. bloom Bull Creek Valley at approximately 10 cm intervals. Carbon dates predominantly in the spring after periods of high discharge [1], as ranged from ~33,000 years before present to recent. The clay part of a cohort of diatoms that includes other bloom-forming taxa fraction was separated from the bulk soil and then digested by a [2]. Comparison of community composition with physico-chemical series of strong acid treatments. Residues were resuspended in characteristics of Little Lagoon showed a very high correlation ammonium hydroxide and prepared for transmission electron between the degree of dominance by diatoms and water age (inferred microscopy (TEM) by centrifugation onto grids with carbon support from the excess 224Ra:223Ra ratio) when subsurface resistivity films. Grids were analyzed with TEM, high-resolution TEM showed that the water table was high. There was no correlation (HRTEM), energy-dispersive x-ray analysis (EDS), and electron between community indices and water age when the water table was energy loss spectroscopy (EELS). low. Nanodiamonds were identified in multiple horizons, including The surficial aquifer is contaminated with very high N (up to sediment dated to the Younger Dryas. Individual grains ranged from c. 5 mM DIN plus DON) and the sediments in Weeks Bay and Little approximately 3-50 nm, although most grains were 5-10 nm. Most Lagoon have even higher concentrations of both N and P. Although or all grains correspond to the n-diamond polymorph, as suggested the supply of nutrients by groundwater is important in supporting by lattice fringe spacings. Lesser amounts of cubic nanodiamonds very dense blooms, the magnitude of discharge is likely as important qwere also tentatively identified. EELS of these particles was in structuring the community. The conditions under which both consistent with sp3-bonded carbon. Other micron-scale particles dinoflagellate and diatom blooms occur are consistent with morphologically similar with those previously identified as ordination of their niches in terms of habitat productivity and hexagonal diamond [3] were graphene/graphane mixtures based on stability [3]. Because global climate change is predicted to alter electron diffraction and EELS. seasonal patterns of precipitation, hence aquifer discharge, it is

likely that the niches for these HAB taxa will expand. [1] Kennett et al. (2009) Science 323, 94. [2] Daulton et al. (2010) PNAS 107, 16043-16047. [2] Kennett et al. (2009) PNAS 106, 12623-12628. [1] Liefer et al. (2009) Harmful Algae 8: 706-714. [2] MacIntyre et al. (2011) J. Plankt. Res. 33: 273–295. [3] Grime (1977) Amer. Natur. 111: 1169-1194.

Mineralogical Magazine | www.minersoc.org 2051 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Reactive transport in compacted Modeling Eu(III) sorption on granite 1* 1 1 2 bentonite: porosity concepts, K. MAEDA , K. FUKUSHI , Y. HASEGAWA , Y. YAMAMOTO , 2 2 experiments and applications D. AOSAI AND T. MIZUNO 1 1 1 2 Kanazawa Univeristy, Kanazawa, Japan, [email protected] URS MÄDER *, ANDREAS JENNI , RAÚL FERNÁNDEZ , AND 2 u.ac.jp (presenting author) ISABEL DE SOTO GARCÍA 2Japan Atomic Energy Agency, Mizunami, Japan 1University of Bern, Geological Sciences, Bern, Switzerland * [email protected], [email protected] There have been very few researches for the trace elements 2Universidad Autonóma de Madrid, Departamento de Geología y sorption on complex mineral assemblages such as rocks, sediments Geoquímica, Madrid, Spain, and soils. In order to make predictions for the trace elements [email protected],[email protected] migration on geologic media, it is crucial to understand the nano- scale interaction of trace elements with complex mineral Porosity concepts and scales assemblages, and to construct the thermodynamic sorption models Chemical and transport processes in compacted bentonite are based on the molecular-scale information. In the present study, the operating at the nanometer scale of smectite interlayers but cannot batch sorption experiments of Eu(III) on granite were conducted as be resolved at this scale by analytical or imaging techniques. function of pH and ionic strength. The sorption behavior was Porosity concepts are treated as macroscopic averaged properties modeled based on our microscopic observation (Hasegawa et al. this but are based on the microscopic scale using electrostatics and volume). explicit or averaged Poisson-Boltzman theory for the distribution of The granite sample was collected from a borehole at a depth of electrolyte species adjacent to mineral surfaces bearing permanent 400 m from the Mizunami Underground Research Laboratory charge. Implementation into reactive transport numerical models is constructed by Japan Atomic Energy Agency in central Japan. The debated, ranging from an averaged single-phase solid-liquid granite was visually fresh. However, the microscope observation and electrolyte [1] to complex multi-porous models assigning transport the X-ray diffraction analysis of clay fraction show the occurrences parameters specific to each type of porosity [2]. Here, we examine of smectite, chlorite, vermiculate, calcite and hydrous iron oxides. the relative merits and limitations of different multi-porous models Eu(III) sorption experiments on granite in the Teflon vessels were as applied to experimental data of various complexity. conducted as function of pH (2 to 8), ionic strength (I=0.01 and 0.1)

and Eu concentration (1 and 10 uM) under ultra-pure N2 atmosphere Reactive transport modelling of experimental data in room temperature. A long-term multi-component advective-diffusive reactive The experiments and modeling results are shown in the Figure. transport experiment with compacted bentonite can be modelled Sorption ratio of Eu(III) was almost zero at pH 2. They abruptly satisfactorily with either a dual porous concept (small proportion of increase with pH up to 3.5. Above pH 3.5, the sorption ratio charge-balanced “free” eletrolyte, large proportion of interlayer- indicates almost constant. The sorption strongly depends on ionic type electrolyte with Donnan approximation), or more complex strength at the pH more than 3.5. Our microscopic observations model assigning separate porosities to the interlayers and a pore show that Eu(III) is selectively scavenged by biotite and that sorption space close to external surfaces of smectite particles. Transport of mode of Eu(III) is identified to be exchange reaction with inter-layer the solvent was additionally constrained by a D2O tracer. K in biotite and Eu(III). The sorption behaviors at pH more than 3.5 Modelling of short-term simple major-component through- are consistent with the cation exchange reaction. At low pH diffusion experiments is not discriminating between models of conditions, less than pH 3.5, the release of the Al and/or Fe must various complexity and leads to a strong dependency of transport occur with dissolution of minerals. The Al and/or Fe should be coefficients on the porosity concept. competed with Eu(III) 100 PHREEQC and Crunchflow were used as numerical models, on the exchange site both capable of treating multiple porosities, electrostatics in the of biotite. The 80 form of diffuse-layer theory, and species-specific and porosity- sorption modeling is 60 specific transport properties. simply considering ( ion exchange reaction 40 Sorption (%) References [1] Birgersson M. & Karnland O. (2009) Geochim. and solubility of Eu1ȣMࠉNaCl0.01M Cosmochim. Acta, 73, 1908-1923. [2] Tournassat C. & Appelo 20 Eu1ȣMࠉNaCl0.1M hydrous iron oxide. Eu10ȣMࠉNaCl0.01M C.A.J. (2011) Geochim. Cosmochim. Acta, 75, 3698-3710. Eu10ȣMࠉNaCl0.1M The model reasonably 0 2 3 4 5 6 7 reproduces the pH overall sorption Fig. Sorption behavior of Eu(III) on granite behavior.

Ref.: Y. Hasegawa, K. Fukushi, K. Maeda, Y. Yamamoto, D. Aosai and T. Mizuno: “Identification and characterization of phase governing Eu(III) uptake in granite by microscopic observations”, In this volume

Mineralogical Magazine | www.minersoc.org 2052 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts More than just "brown layers": SIMS sputter pit volume estimation Manganese in Quaternary Arctic in SHRIMP zircon analysis using an 18 - Ocean sediments O2 primary beam

1,2,* 2 3 1* 2 2 C. MÄRZ , A. STRATMANN , J. MATTHIESSEN , S.W. CHARLES W. MAGEE JR. , JIM FERRIS , CHARLES W. MAGEE 1 2 2 2 POULTON , A.-K. MEINHARDT , S. ECKERT , B. SCHNETGER , 1 4 3 2 Australian Scientific Instruments, Canberra, Australia, C. VOGT , R STEIN AND H.-J. BRUMSACK [email protected] (* presenting author) 1School of Civil Engineering and Geosciences, Newcastle 2Evans Analytical Group, East Windsor NJ, USA University, UK, [email protected] (* presenting author) 2Institut für Chemie und Biologie des Meeres, Carl-von-Ossietzky- Abstract Universität Oldenburg, Germany A novel method of estimating the volume of sputtered material 3Alfred-Wegener-Institut für Polar- und Meeresforschung, was discovered while performing SHRIMP (Sensitive High- Bremerhaven, Germany Resolution Ion MicroProbe) zircon U/Pb geochronology using an 4 18 - ZEKAM, Fachbereich Geowissenschaften/MARUM, Universität O2 primary beam. During analysis, the ratio of Th and U oxide Bremen, Germany isotopologues was found to be equal for each individual spot. Assuming that the U16O/U18O (or Th16O/Th18O) ratio was equal to In Quaternary deposits of the Arctic Ocean, brown Mn-rich the 16O/18O ratio of the sputtered material, multiplying this by the layers are well-known, widespread, but also debated features. Both total 18O primary beam fluence (true beam current times analytical glacial-interglacial climatic variations (in river runoff, bottom water time) yields total sputtered oxygen. Dividing by the density of ventilation etc.) and early diagenetic processes might explain the oxygen in the zircon crystal lattice (about 63 atoms per nm3) yields sedimentary Mn distributions. We applied inorganic geochemical an analytical volume. analyses to pore waters and sediments of two sediment cores from Comparison with pit volumes from AFM (Atomic Force the western Arctic Mendeleev Ridge (RV Polarstern Expedition Microscopy) shows that this isotopic volume estimation agrees with ARK-XXIII/3) [1]. Our results show that most brown layers are AFM pit measurements to within 10%. This relationship holds for associated with detrital (ice-rafted) and biogenic carbonate primary beam impact energies from 5 to 15 kV. enrichments. In addition, all Mn-rich layers are enriched in Fe This agreement in volume between isotopic and AFM (oxyhydr)oxides, and in Co, Cu, Mo and Ni that were most probably measurements suggests that oxygen migration in the sputtering scavenged by Mn/Fe (oxyhydr)oxides. Distinct bioturbation patterns process is limited. As oxygen activity is crucial to governing the (i.e., brown burrows into the underlying sediments) suggest these Pb/U vs UO/U calibration that makes accurate SIMS U/Pb metal enrichments formed close to the sediment–water interface. geochronology possible, further investigations are planned into We infer that the metal-rich layers formed under warmer minerals such as baddeleyite, which calibrate poorly. (interglacial/interstadial) conditions with an intensified continental As the SHRIMP duoplasmatron consumes only $50-$100 of 18 hydrological cycle and only seasonal sea ice cover. Metals were O2 per day, this method appears to be cost-competitive with paying delivered to the ocean by rivers/sea ice/coastal erosion [2], while for analytical time on a second instrument for analytical volume seasonal productivity increased the reactive organic matter export to determination. However, it requires that the sample and the primary the sea floor. The coeval deposition of organic matter and Mn/Fe beam are the only sources of oxygen in the sputtering process. (oxyhydr)oxides triggered an intense diagenetic Mn and Fe cycling at the sediment-water interface. These climate-induced primary and secondary processes resulted in the enrichments of Mn/Fe (oxyhydr)oxides, scavenging of trace metals, and the degradation of labile organic matter. With the onset of glacial/stadial conditions, the riverine/erosive delivery of metals strongly decreased, a solid sea ice cover terminated the production and export of fresh organic matter, and gray-yellowish sediments with lower metal contents were deposited. Our data do not support glacial/stadial bottom water oxygen depletion that might have affected the Mn distribution. Despite the climatic control on the composition of the brown layers, pore water data show that diagenetic redistribution of Mn and Mo is still affecting the deeper sediments. The degree of Mn remobilisation (potentially causing complete dissolution of existing, and formation of new Mn layers) largely depends on the availability and reactivity of Mn (oxyhydr)oxides and organic matter.

[1] C. März, A. Stratmann, J. Matthiessen, A.-K. Meinhardt, S. Eckert, B. Schnetger, C. Vogt, R. Stein, H.-J. Brumsack (2011) Geochim. Cosmochim. Acta 75, 7668-7687. [2] R.W. Macdonald and C. Gobeil (in press) Aquat. Geochem.

Mineralogical Magazine | www.minersoc.org 2053 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Measurement of nitrous oxide Oxygen isotopes from Chinese caves: isotopologues and isotopomers by the records not of monsoon rainfall but MAT 253 Ultra circulation regime

1* 1 1 1 , 2 PAUL MAGYAR , SEBASTIAN KOPF , VICTORIA ORPHAN BARBARA A MAHER * ROY THOMPSON 1 AND JOHN EILER 1University of Lancaster, Lancaster, UK, [email protected] 1California Institute of Technology, Pasadena, CA, USA, (* presenting author) [email protected] (* presenting author) 2University of Edinburgh, [email protected]

18 The global budget of nitrous oxide is dominated by terrestrial Current interpretation of cave Ɂ O records and marine biological sources and atmospheric sinks. Details of the Oxygen isotope variations in Chinese stalagmites have budget remain unclear, including the cause of increasing been widely interpreted as a record of the amount of East Asian summer monsoonal rainfall. This interpretation infers decreasing atmospheric N O concentrations. Marine sources of N O include 2 2 monsoonal rainfall from the mid-Holocene and large, dipolar denitrification and nitrification. Our understanding of the major 18 rainfall oscillations within glaciations. However, the cave G O microbial players in the nitrogen cycle has changed in recent years variations conflict with independent palaeoclimate proxies (cave (for example, the nitrifying Archaea), and the overall contributions G13C, loess/palaeosol magnetic properties, n-alkanes), which of these organisms to N2O production and their isotopic signatures indicate no systematic decline in rainfall from the mid-Holocene, are poorly constrained [1]. and no glacial rainfall maxima. Here we examine the suitability of the MAT 253 Ultra, a new high resolution gas source mass spectrometer [2], for measurements Mass balance calculations show moisture source is key of rare, previously unanalyzed isotopologues and isotopomers of control Using mass balance calculations, we demonstrate that the cave N2O, including ‘clumped’ species and high-precision direct analysis 18 of 17O-substituted species. Such measurements could provide G O variations cannot be accounted for by summer rainfall changes, nor rainfall seasonality nor winter cooling, but instead reflect additional constraints to the global cycle of N O, and in particular 2 changes in moisture source. A possible driver of the G18O variations offer a fresh opportunity for distinguishing among biosynthetic N2O in Chinese stalagmites is precessional forcing of inter-hemispheric sources. Preliminary experiments include examining N2O produced temperature gradients, in a mechanism similar to that of the modern by pure cultures of denitrifying bacteria. day Indian Ocean dipole. Through such forcing, Indian monsoon- In the instrument’s ‘medium resolution’ setting (16 μm entrance sourced G18O may have dominated at times of high boreal summer slit; resolving power ~16-18,000, M/∆M), [14N15N18O + 15N14N18O] insolation, local Pacific-sourced moisture at low insolation. is well resolved from 13C18O16O and the 15N18O fragment from Suppression of summer monsoonal rainfall during glacial stages may 17 18 reflect diminished sea and land surface temperatures and the O O. In zero-enrichment measurements, precision of 0.2‰ was radiative impacts of increased regional dust fluxes. achieved for mass 47 species and 0.4‰ for 15N18O; both equaled

counting statistics limits for the integration times used (11 and 17 minutes, respectively) and should be improved by increasing the source pressure, reducing resolution (e.g., using a 20 μm entrance 14 17 slit) or increasing counting time. At mass 45, N2 O is well resolved from [14N15N16O + 15N14N16O], with external precision of 0.03‰ achieved after 11 minutes of integration (again, counting statistics limited and potentially improvable). By measuring both these species (as well as unsubstituted and singly substituted isotopologues), the position-specific clumping (i.e., clumping of 15N with 18O, and its dependence on site preference of 15N) can be examined. Such measurements will

complement the information already available from N2O site preference measurements alone. Calculations suggest that site 15 preference of N in thermodynamically equilibrated N2O will differ by ~1‰ between 16O and 18O isotopologues [3]. A larger range of signals could arise from photochemical and biological fractionations. Precise measurement of 17O will enable detection of even subtle contributions of atmospheric mass-independent fractionation, or study of variations in mass laws of biological and other fractionations.

[1] Santoro et al. (2011) Science 333, 1282-1285. [2] Eiler et al. The MAT 253 Ultra — a novel high-resolution, multi-collector gas source mass spectrometer. Goldschmidt 2012. [3] Wang et al. (2004) Geochim. Cosmochim. Acta 68, 4779-4797.

Mineralogical Magazine | www.minersoc.org 2054 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Defining the chemical and physical Assessing limitations for PAH length and time scales that control biodegradation in long-term chemical fluxes from landscapes contaminated soils using 1* 1 1 KATE MAHER , CLAIRE KOUBA , ALEX K. HEANEY AND bioavailability assays 1 VALERIE B. ROSEN 1* 1 2 NAGISSA MAHMOUDI , GREG SLATER AND ALBERT JUHASZ 1 Dept. of Geological and Environmental Sciences, Stanford 1School of Geography and Earth Sciences, McMaster University, University, Stanford, CA, USA, [email protected] (* 1280 Main St. W., Hamilton, ON, Canada presenting author) (*[email protected]) ([email protected]) As fluids move through the subsurface they acquire solutes at a 2Centre for Environmental Risk Assessment and Remediation rate that is controlled primarily by the available surface area, the (CERAR), University of South Australia, Adelaide, SA, Australia reaction kinetics of the individual minerals and the thermodynamic ([email protected]) departure from chemical equilibrium [1]. As a result, both the physical length scale (or cumulative mineral surface area) and the Polycyclic aromatic hydrocarbons (PAHs) are a class of time available for the fluid to react (or the fluid residence time) organic contaminants that are ubiquitous in the environment through should exert a coupled influence on the solute fluxes from a given the incomplete combustion of organic matter such as diesel, coal landscape. For example, if actual fluid residence times exceed the and wood as well as being present at industrial sites due to use in a theoretical time required to reach chemical equilibrium, then the range of industrial processes. Once PAHs enter the environment, the solute fluxes are optimized. However, because rivers and streams predominant mechanisms for removal are biological via microbial average over spatial domains that include an array of length scales activity, although physiochemical processes such volatilization can and fluid residence times, determining the length and time scales reduce the concentration of some PAHs. However, due to their that control solute generation has proven difficult. Defining and hydrophobic structure, PAHs have the potential to partition onto soil linking these length and time scales presents a key challenge to organic matter thereby decreasing their bioavailability to fields of geochemistry, geomorphology, biology and hydrology. Yet, microorganisms and limiting their degradation in the environment. if the length and time scales that control solute fluxes could be This explanation was felt to be the reason for a lack of evidence of defined, this knowledge may provide a mechanistic approach for PAH biodegradation in a study of long-term contaminated soils. interpreting catchment to global-scale solute fluxes. Instead, natural organic matter was being utilised as a carbon source A comparison between soil profile solute evolution from stable resulting in the persistence of PAHs at this site [1]. and eroding landscapes, and concentration-discharge relationships Although biodegradation may be limited by a variety of (C-Q) both for small rivers from the U.S. Geological Survey’s environmental factors, bioavailability is considered to be a major Hydrologic Benchmark Network (HBN) and large rivers from the limitation in contaminated soils. To test the hypothesis that Global Environmental Monitoring System (GEMS) database bioavailability was the limiting factor for biodegradation in theses suggests that even with increasing discharge and catchment area, the soils, PAH bioavailability was determined using non-exhaustive ratio between the physical and chemical length scales may remain extraction (propanol, butanol, hydrooxypropyl-β-cyclodextrin) and relatively constant. Catchments that show little variability in oxidation (persulfate) methodologies designed to determine the concentration with discharge (or “chemostatic behavior”) are fraction of contaminants within soil which are available for characterized by average fluid residence times that exceed the time biological uptake [2, 3]. By comparing the initial PAH required to reach chemical equilibrium. Chemostatic rivers may concentrations to the residual PAH concentrations following each also represent rivers that are at their optimal solute flux. Conversely, assay, it was determined that the majority of PAHs in the soils were decreases in concentration with increasing discharge are explained inaccessible to microorganisms which suggested that bioavailability by average residence times shorter than required to approach limitations were the primary cause for the lack of observed chemical equilibrium, resulting in dilution. In these systems, if fluid biodegradation at this site. residence times increase or chemical equilibration lengths decrease, These results highlight the importance of bioavailability to PAH solute fluxes are expected to increase to the optimum level. The degradation as well as the effectiveness of these assays as a rapid, fluid residence time model could provide an alternative framework and inexpensive method for determining the endpoints of PAH for assessing both the relationship between discharge and bioremediation. Such assays have the potential to provide a decision concentration for individual catchments and controls on the solute making tool on the suitability of bioremediation for soil treatment fluxes of larger rivers. However, more detailed studies of the with minimal cost and time impacts and high accountability. chemical and physical length and time scales and the development of scaling approaches are necessary to refine the simple model [1] Mahmoudi et al. (2011), submitted to Env Sci & Technol presented here. In particular, the time required to reach chemical [2] Juhasz et al. (2005) Biorem J 9, 99-114. [3] Dandie et al. (2010) Chemosphere equilibrium is perhaps the most poorly constrained variable in the 81, 1061-1068. fluid residence time model.

[1] White, A.F., et al. (2008) Geochim. Cosmochim. Acta, 73, 2769- 2803.

Mineralogical Magazine | www.minersoc.org 2055 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Aerosol impacts on climate and Characterization of Corn Rhizosphere biogeochemical cycles (Zea mays) Grown in

NATALIE MAHOWALD1, DANIEL WARD1*, SILVIA KLOSTER2, Metal-contaminated Soil MARK FLANNER3, COLETTE HEALD4, NICHOLAS HEAVENS1, PETER HESS5, JEAN-FRANCOIS LAMARQUE6, PATRICK CHUANG7 1 1 NAHED MAHROUS *, SHEILA MACFIE AND GORDON 1Earth and Atmospheric Science, Cornell University, Ithaca, United SOUTHAM1,2 States, [email protected] (* presenting author) 1 2Land in the Earth System, Max Planck Institute for Meteorology, Department of Biology, The University of Western Ontario, Hamburg, Germany London, Canada, N6G 5H4, [email protected] (*presenting 3Atmospheric, Ocean, and Space Sciences, University of Michigan, author) 2 Ann Arbor, United States Department of Earth Sciences, The University of Western

4Atmospheric Science, Colorado State University, Fort Collins, Ontario, London, Canada, N6G 5H4 United States As industrialization encroaches on agricultural settings, it has 5Biological and Environmental Engineering, Cornell University, become increasingly more important to investigate the microbe- Ithaca, United States mineral interactions within the rhizosphere. Currently, there is an 6Atmospheric Chemistry Division, National Center for Atmospheric incomplete understanding of metal contaminants and distribution Research, Boulder, United States (i.e., the bioavailability of different forms of metals) in soils that 7Earth and Planetary Sciences, University of California, Santa Cruz, result in the uptake and accumulation in plants [1]. A more focused study on metal concentrations in edible plants is important to avoid United States possible risks to human health [2]. In this study, the examination of

the rhizosphere was made possible by developing a new Aerosols play an important role in our understanding of the embedding procedure resulting in successful preservation of the Earth’s climate through direct interactions with atmospheric radiation inorganic and organic materials, i.e., structure and chemistry, and indirect interactions by modifying cloud properties. These within the rhizosphere (Figure 1). impacts take place on timescales in the troposphere of days to weeks. Longer timescale impacts of aerosols on climate through 100 μm biogeochemical feedbacks are less well understood. Aerosols transport mass which may include nutrients or toxins across long distances and have been shown to effect the production of ecosystems that are distant to the aerosol source. The purveyors of these important nutrients are often naturally emitted aerosols such as mineral dust, volcanic ash, or biomass burning aerosols. Natural Figure 1: A BSE-SEM micrograph of a soil core containing roots aerosols have generally received less study than anthropogenic and soil, i.e., rhizosphere. aerosols, but here we use model simulations of preindustrial and present day aerosols to isolate the relative importance of different ICP-AES analysis demonstrated that concentrations of aerosol types for various climate impacts. Radiative forcings for the bioavailable metals (Cd, Cu, Pb and Zn) were higher within the rhizosphere than the bulk soil. While the bacterial communities different aerosol types are estimated from the literature. We also give within the bulk soil and rhizosphere were capable of using similar estimates for the contributions of various aerosol sources and types to types of carbon for growth, i.e., biodiversity was not affected by nutrient transport in the atmosphere. the growth of corn, the activity of the bacterial community The impacts of aerosols on ecosystem production feedback onto inhabiting the rhizosphere (measured by using the Biolog TM the climate by changing the amount of carbon emitted or sequestered Ecoplate system) was greater than the soil control. This increase in activity, which was reflected by a decrease in pH in the by the affected ecosystem. In addition, aerosols modify the carbon rhizosphere, can presumably be expected to influence heavy metals uptake capacity of the land surface and the ocean by altering climate uptake by plants. The use of scanning electron microscopy through these biogeochemical effects and the more commonly combined with energy dispersive spectroscopy (SEM-EDS) and referenced direct and indirect cloud effects. wavelength dispersive x-ray spectroscopy (SEM-WDS) revealed Here we present the first quantitative assessment of the total the presence of particles containing lead (Pb). Under these conditions, the use of micro-synchrotron x-ray fluorescence indirect effects of aerosols onto climate through their effects on (micro- XRF), x-ray absorption fine structure (XAFS) and x-ray biogeochemical cycles. The aerosol indirect biogeochemistry effect is absorption near edge structure (XANES) are required to probe the found to be similar in magnitude to the aerosol direct effect, with spatial and chemical relationships of plant roots and the soils in higher uncertainties, and yet the impacts on climate could be even which they grow. greater because the biogeochemical impacts take place over longer

time scales. The cooling influence of the indirect biogeochemical [1] Chen & Cutright (2001). Chemosphere. 45, 21-28. [2] Kamnev effects suggests that abatement costs for projected CO2 & Lelie (2000). Bioscience Reports. 20, 239-258. concentrations could be underestimated. Due to the potential importance for our understanding of the land-atmosphere-ocean coupled climate and for policy, aerosol indirect effects on

biogeochemistry warrant greater consideration in studies of aerosol and climate interactions.

Mineralogical Magazine | www.minersoc.org 2056 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts U(VI) sorption on montmorillonite in Radiocarbon Analysis of Microbial the presence of phosphate. DNA and PLFA from Arsenic

F. MAILLOT1*, J.G. CATALANO1, D.E. GIAMMAR2 Impacted Aquifers in Bangladesh. 1* 1 1Earth & Planetary Sciences, Washington Univ., St. Louis, MO BRIAN J. MAILLOUX , ELIZABETH TREMBATH-REICHERT , 1 1 1 63130, USA, [email protected] (*presenting author), JENNIFER CHEUNG , MARLENA WATSON , AUDRA DOCHENETZ , 1 2 3 [email protected] MARTIN STUTE , GREG A. FREYER , ANDREW FERGUSON , 2 4 4 5 Energy, Environmental and Chemical Engineering, Washington KAZI MATIN AHMED , MD, J. ALAM , BRUCE A. BUCHHOLZ , 6 6 7 Univ., St. Louis, MO 63130, USA, [email protected] GREG F. SLATER , LORI A. ZIOLKOWSKI , JAMES THOMAS , 8 9 9 ALICE LAYTON , YAN ZHENG , ALEXANDER VAN GEEN Uranium (U) contamination of soils and groundwater is a serious 1Environmental Science Department, Barnard College, NY, NY environmental concern due to past mining, processing, and waste 10027, USA. [email protected] disposal activities. In oxidizing environments, U(VI) is the most 2Environmental Health Science, Columbia University, NY, NY stable valence state for uranium, occurring in the linear uranyl ion, 10032, USA UO 2+. Among the in-situ remediation strategies for oxic subsurface 2 3Department of Civil Engineering and Engineering Mechanics, environments, phosphate-based treatments have generated significant Columbia University, NY, NY 10027, USA interest. U(VI) has a strong affinity for phosphate, which can lead to 4Department of Geology, University of Dhaka, Dhaka 1000, the nucleation of low-solubility U(VI)-phosphate minerals or enhance Bangladesh U(VI) sorption to subsurface minerals via the formation of ternary 5 surface complexes. In addition, U(VI)-phosphate associations are Center for Accelerator Mass Spectrometry, Lawrence Livermore National Lab, Livermore, CA 94551-9900, USA common forms of U(VI) in contaminated soils and sediments at U.S 6 Department of Energy (DOE) facilities, and have been observed in Geography & Earth Science, McMaster University, Hamilton, ON L8S 2S4, Canada the Hanford 300 Area, the Oak Ridge Reservation, and the Fernald 7 Site. However, the molecular mechanisms controlling U(VI) Hydrologic Sciences, Desert Research Institute, Reno, NV, 89512, speciation in heterogeneous phosphate-bearing systems are currently USA 8 poorly constrained, which hinders the design of efficient remediation Dept of Microbiology and Center for Environmental Biotechnology, strategies and the prediction of uranium transport in treated systems. University of Tennessee, Knoxville, Tennessee, USA 3- 9 Previous work by coworkers in the U(VI)-PO4 -goethite (D- Lamont-Doherty Earth Observatory, Columbia University, FeOOH) system [1] has pointed towards the existence of ternary Palisades, NY 10964, USA surface complexes at the goethite surface. The characterization of Abstract these species was possible thanks to the use of extended X-ray It is generally agreed that microbial respiration drives the release absorption fine structure (EXAFS) spectroscopy at the uranium L - III of arsenic from the sediment to water in drinking water aquifers edge. Following a similar approach in the present work, we investigated the effect of phosphate on U(VI) sorption on throughout Southeast Asia. This microbial respiration requires montmorillonite, a dioctahedral 2:1 clay mineral. Montmorillonite organic carbon, and it is this source of organic carbon that is poorly was chosen because phyllosilicate clays are a common component of constrained. It has been hypothesized that the carbon could be the fine fraction of soils and sediments at many DOE sites. Previous derived from: 1) young anthropogenic sources, 2) carbon deposited work has also shown that montmorillonite is a strong sorbent for with the sediments, 3) carbon from organic rich peat lenses, or 4) U(VI) [2,3]. In order to identify chemical divides that separate regimes where older petroleum byproducts. However, no method is currently specific mechanisms (e.g. ternary surface complexation or available to directly determine the source of organic carbon. In order precipitation of U(VI) phosphates) dominate, we determined U(VI) to better constrain the source of organic carbon we developed a 3- adsorption isotherms as a function of [PO4 ], pH, P CO2, and method to determine the radiocarbon signature of microbial DNA electrolyte cation. To further characterize the nature of U(VI) and phospholipids fatty acids (PLFAs) from groundwater samples. speciation in these separate regimes, relevant samples were analyzed in more detail using EXAFS and XRD. Besides providing new The radiocarbon signatures of the DNA and PLFA will reflect the 3- knowledge of the U(VI)-PO4 -montmorillonite system, comparison source of organic carbon utilized by heterotrophic microbes. For with the previously studied goethite system will allow determinations DNA, the method includes filtering over 2,000 liters of groundwater of how sorbent structure influences uranium-phosphate reactions in onto a 0.2 μm filter followed by DNA extraction and purification. heterogeneous systems, which is fundamental for potential remediation applications involving real soils and sediments. For PLFAs the method includes filtering over 1,000 liters of This work is supported by the U.S Department of Energy, Office groundwater onto a newly developed carbon free filter. The DNA of Biological and Environmental Research, Subsurface method enables us to collect, extract, and purify over 150 μg of DNA Biogeochemistry Research Program through grant DE-SC0006857. with an absorbance at 260/280>1.8 and an A260/230>2; indicating pure DNA. The new method was utilized at Site F in the Lashkardi [1] Singh et al. (2010) Geochim. Cosmochim. Acta 74, 6324-6343. Village, Araihazar, Bangladesh. The site represents an area where [2] McKinley et al. (1995) Clays and Clay Minerals, 43, 586-598. [3] Turner et al. (1996) Geochim. Cosmochim. Acta 60, 3399-3414. rapid recharge of anthropogenic carbon might occur. Results indicate that in the Holocene Aquifer the DNA is significantly older than groundwater ages and does not contain modern carbon but is younger than estimated sediment ages. We hypothesize that the carbon in the aquifer is recharged at the water table and is significantly retarded as it is tranported to depth. Further utilization of this novel method should help to better constrain the carbon sources driving arsenic release in the shallow aquifers of Southeast Asia.

Mineralogical Magazine | www.minersoc.org 2057 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Constraining E- and N-type Identity of oxidation products on components in Baffin Island picrites surface of metallic antimony 1* 2 3 1* 1 MELISSA MAISONNEUVE , DON FRANCIS , AND JOHN STIX FRANTISEK MAJS ,ANASTASIA G. ILGEN ,AMANDA J. 1,2 2 1 BARKER ,THOMAS A. DOUGLAS , AND THOMAS P. TRAINOR 1McGill University, Earth and Planetary Sciences, [email protected] (* presenting author) 1University of Alaska Fairbanks, Chemistry and Biochemistry, 2McGill University, Earth and Planetary Sciences, [email protected]*, [email protected], [email protected] [email protected], [email protected] 3McGill University, Earth and Planetary Sciences, 2US Army Corps of Engineers, Cold Regions Research and [email protected] Engineering Laboratory, Fort Wainwright, AK, [email protected] The Baffin Island picrites are interpreted to represent primitive magmas (up to ~22 wt% MgO) that are minimally changed since Introduction leaving their mantle source. Lead and neodymium-samarium Small arms bullets are predominantly made of lead (Pb) but isotopes indicate that these lavas may be melts of a primordial antimony (Sb) is commonly used to harden bullets and can comprise mantle reservoir (~4.45-4.55 Ga). Silicate melt inclusions (MIs) up to 10% of the total mass. The fate of Pb in firing range soils has trapped within olivine crystals during their crystallization are considered to be aliquots of their parental melts and thus their been investigated in a number of studies while the fundamental compositions provide a unique insight into the geochemical nature geochemical processes controlling the fate of Sb in soils and surface of the oldest known terrestrial mantle reservoir. water are largely unknown. Anthropogenic deposition of Sb to soils In this study, the ratio of potassium to titanium (K/Ti) is used as on military and recreational shooting ranges represents an an analog for trace element enrichment as both these elements are environmental risk due to Sb toxicity. Oxidation of bullet fragments incompatible in the olivine and plagioclase phenocrysts present in containing metallic antimony under surface soil conditions ultimately these lavas. We define depleted glass compositions (N-type) as leads to the release of Sb(V) to the soil solution and an accumulation those with K/Ti < 0.2 and enriched glass compositions (E-type) as those with K/Ti > 0.2, based on an apparent population minimum at ~ of Sb(V) in soil. While Sb(III) is usually absent from soil solution or 0.2. The N-type MIs are characterized by low K/Ti, La/Lu, Zr/Y and contaminated soil, its oxide (Sb2O3) precipitates readily during chlorine contents ( Cl ≤ 50 ppm) while the E-type MIs appear to be oxidation of Sb(0) under model conditions with deionized water and mixtures of two distinct liquids, one a depleted end-member similar simulated groundwater. Mechanisms controlling speciation of in composition to the N-type MIs and the other an enriched end- precipitated Sb2O3 as well as relationship between solid and aqueous member characterized by high K/Ti, La/Lu, Zr/Y and chlorine Sb speciation are not clearly understood. contents ( 50 ≤ Cl ≤ 200 ppm). The chlorine concentration increases with trace element enrichment in E-type MIs which may indicate a relatively high Cl content in the E-type component. Methods Whereas N-type MIs are hosted in olivines with a narrow range of The experimental study focused on understanding the effect of + 2+ forsterite contents, from Fo89 to Fo87, the E-type MIs are found common cations (Na , Ca ) on the formation of precipitates on an mostly in olivines with lower Fo contents (Fo87-Fo83), suggesting Sb(0) surface during oxidation in simulated groundwater. Solutions either the incorporation of the E-type component occurred later in were prepared at fixed ionic stregth (I = 0.01 mol L-1) and a range of the crystallization history of the N-type magmas or that the E-type environmentally relevant pH values. We compared these results to the component was less magnesian. same processes in background solutions containing either deionized

water or 30% hydrogen peroxide (H2O2). We determined the speciation and preferred orientation of the precipitates with grazing incidence x-ray diffraction and texture measurements, respectively. Results of the laboratory experiments were compared to Sb(0) weathered under field conditions in soils of varied texture and pH.

Results and Conclusion

The surface of Sb(0) oxidizes rapidly and within 24 hours we Figure 1: Melt inclusions in olivine crystal. Field of view is observed the formation of cubic and orthorhombic polymorphs of approximately 1 mm. Sb2O3 (senarmontite and valentinite) of which valentinite exhibited strong preferential orientation with the a axis normal to the Sb(0) The large variation in K/Ti (0.05 to 0.6) in multiple melt surfaces. An oxidation end member, hydrated Sb2O5, precipitated on inclusions within single olivine crystals suggests either that the Sb(0) surfaces only under the extremely oxidizing conditions of the growth of olivine phenocrysts during the magmatic differentiation of H O solution. The valentinite fraction in the precipitate increases the N-type magma records the incorporation of the E-type 2 2 component, or that the E- and N-type components were intermixed with increasing solution pH but no measurable difference in + 2+ on a fine scale. The presence of two finely intermingled magmatic speciation was found between Na and Ca background solutions. components in the mantle source of the Baffin picrites implies that Drawing a connection between environmental conditions like soil pH Earth’s primordial mantle was as heterogeneous as the and Sb(0) oxidation mechanisms helps to predict the fate of spent asthenospheric source of modern-day mid-ocean ridge basalts. bullets and assists land managers in identifying appropriate soils to use in constructing new shooting ranges.

Mineralogical Magazine | www.minersoc.org 2058 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Thermodynamic prediction of Fracture Mineral Investigation in aqueous As concentration in Crystalline Rock, SW Greenland 1* 1 2 scorodite-rich tailings W.R.M. MAKAHNOUK , S.K. FRAPE , A.R. BLYTH , 3 1 4 T. RUSKEENIEMI , M. CONIGLIO , AND R.J. DRIMMIE JURAJ MAJZLAN 1University of Waterloo, Earth & Environmental Sciences Institute of Geosciences, Burgweg 11, Friedrich-Schiller University, [email protected] [email protected] [email protected] D-07749 Jena, Germany, [email protected] 2Nuclear Waste Management Organisation (NWMO)

[email protected] Hydrometallurgical processing of As-rich ores for the 3Geological Survey of Finland (GTK) extraction of gold or other metals produce voluminous fine-grained, [email protected] As-rich waste which is disposed of in the tailing ponds and stored in 4Isotope Trace Technologies Inc. (IT2) these facilities over a long time. Under predominantly acidic [email protected] conditions, the principal As carrier in these tailings is the mineral

scorodite, FeAsO4·2H2O. Field and laboratory studies revealed a wide variation of the aqueous As concentrations in such tailings or in Abstract This current study is associated with the Greenland Analogue aqueous solutions with scorodite. This study explains these Project (GAP), an international collaboration between the Nuclear concentrations and their large scatter by thermodynamic modelling Waste Management Organization (Canada), Posiva (Finland), and of scorodite-rich waste. SKB (Sweden). The objective of this project is to further understand For the calculations, we have used recently measured or groundwater evolution in bedrock as influenced by the presence of a estimated thermodynamic properties from our work of As-rich continental ice-sheet. Physical and chemical characteristics of hydrous ferric oxide (As-HFO) [1], scorodite [2], crystalline iron secondary minerals within fracture networks in the bedrock were oxides goethite and lepidocrocite [3], and ferrihydrite [4]. examined to provide insights into paleo-hydrological processes (e.g. At pH < 2.5, scorodite dissolves congruently and controls and hydrothermal, metamorphic, or glacial events). aqueous As concentrations in the tailings. In this region, most of the Two boreholes were drilled into granitic gneiss near the margin experimental studies agree with respect to the measured and of the Greenland ice-sheet. The first was drilled beneath a talik lake predicted As concentrations. 3+ and instrumented to sample groundwater (GAP01). The second Above pH of ~2.5, Fe phases (As-HFO, goethite, borehole was drilled to ~350 m to determine the depth of the lepidocrocite, ferrihydrite) will start precipitating. These reactions 3+ permafrost (GAP03). Preliminary results, specifically, carbon drive the aqueous Fe concentration down, force further dissolution 13 18 5+ (G C) and oxygen (G O) isotope geochemistry of carbonate of scorodite, and hence elevate the aqueous As concentration. As fracture fillings, are now available (Fig. 1). Calcite analyses reveal a each of these phases has a different stability in the environment of 18 3+ vertical G O trend in the GAP01 borehole, indicative of the tailings, the influence of each phase on the Fe and As hydrothermal carbonates. This is further corroborated by the 18O concentration is different. Yet, we show that the majority of the depleted dolomite in that borehole. Dolomite in the GAP03 scattered experimental measurements fall into the field defined by borehole corresponds to a fracture filling that is coated with a thin the models where scorodite dissolves and Fe oxides precipitate. This layer of calcite (arrow identifies isotopic signature in Fig.1), field is bound for the curves which represent the scorodite-goethite indicative of two different crystallization events based on the large (scorodite dissolves, goethite precipitates) and scorodite- difference in G18O values. ferrihydrite model. These two phases are expected to constitute the Ongoing fluid inclusion studies are anticipated to elucidate boundaries of the field because goethite is the most stable and minimum carbonate mineral crystallization (trapping) temperatures ferrihydrite the least stable phase in the system. and fluid salinities. Formation temperatures are used to calculate the Hence, using our data and models, we can reconcile all isotopic composition of the parent fluids from which these published experimental and field data with the thermodynamic values carbonates precipitated. Estimates for G13C of DIC and G18O of for the participating phases. We can also show that the As paleo-fluids are powerful tools to distinguish meteoric or glacial concentrations is likely to change in time as the Fe oxides age and water from fluids that have been subjected to water-rock interaction. transform to more stable phases or phase assemblages.

[1] Majzlan, J. (2011) Environmental Science & Technology 45, 4726-4732. [2] Majzlan, J., Drahota, P., Filippi, M., Grevel, K.-D., Kahl, W.A., Plášil, J., Boerio-Goates, J., Woodfield, B.F. (2012) Hydrometallurgy (in press) [3] Majzlan, J., Grevel, K.-D., Navrotsky, A. (2003) American Mineralogist 88, 855-859. [4] Majzlan, J., Navrotsky, A., Schwertmann, U. (2004) Geochimica et

Cosmochimica Acta 68, 1049-1059.

Figure 1: G13C and G18O isotope signatures of carbonates sampled from Greenland core - calcite (red and blue) and dolomite (green).

Mineralogical Magazine | www.minersoc.org 2059 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts

Detrital zircons from the Higo and Chemistry and petrography of Abukuma metamorphic terranes, detrital magnetite applied to mineral Japan: implication for the sediment exploration in glaciated terrains

provenance S.MAKVANDI1*, G.BEAUDOIN2, B.MCCLENAGHAN3 1* 2 KENSHI MAKI , MAYUKO FUKUYAMA , KAZUHIRO 1Université Laval, Département de géologie et de génie géologique, 3 4 4 MIYAZAKI , TZEN-FU YUI , KUO-LUNG WANG , TADASHI 1100, avenue de la Medecine, Québec, Québec, Canada, G1V 4 1 5 USUKI , TAKAFUMI HIRATA , AND MARTY GROVE 0A6, [email protected] 2Université Laval, Département de géologie et de génie géologique, 1Kyoto University, Kyoto, Japan, k- 1100, avenue de la Medecine, Québec, Québec, Canada, G1V [email protected] (* presenting author) 0A6, [email protected] 2Akita University, Akita, Japan 3Geological Survey of Canada, 601 Booth St., Ottawa, Canada, K1A 3Geological Survey of Japan, AIST, Tsukuba, Japan 0E8, [email protected] 4Academia Sinica, Taipei, Taiwan 5Stanford University, Stanford, California, USA The spinel structure of magnetite has potential to carry unique chemical and petrographic signatures imposed by compositional and In the Cretaceous low-pressure and high-temperature physico-chemical conditions during crystallization and subsequently metamorphic terranes of Japan, the Higo (south-west Japan) and during metamorphism or weathering. The chemical composition of Abukuma (north-east Japan) metamorphic terranes are characterized detrital magnetite is applicable in provenance studies, in particular for by the occurrences of peraluminous metapelitic rocks and impure mineral exploration. Its ubiquity in mineral deposits, its resistance to marbles, and absence of chert, and zircon U-Pb age of ca. 260Ma, weathering and abrasion, and ease of magnetic separation have led suggesting that these terranes might be the eastern extension of the magnetite to be considered an indicator mineral. This study aims to North China-South China collision zone [1,2,3,4]. However, new determine the usefulness of chemistry and petrographic features of results of our zircon SHRIMP and LA-ICP-MS U-Pb dating do not detrital magnetite in mineral exploration in glaciated terrain. A total necessary support the possibility of eastern extension of the North of 186 grains from the 0.18-2.0 mm ferromagnetic fraction of till China-South China collision zone. Lu-Hf isotopic data for the deposited down-ice of the Halfmile Lake VMS deposit (Bathurst detrital zircon may imply that the possible provenance for the Higo Camp) were investigated. To find out the effect of erosion of and Abukuma metamorphic terranes is the South China Craton. surrounding lithologies on the formation of till, 176 grains from The metamoprhic age of ca. 260 Ma could not be replicated hostrocks and magnetite alteration zones in the area were examined. from the Higo and Abukuma metamoprhic terranes in this study. Mineral grains were liberated from rocks using a small plate crusher. Detrital zircons from the Higo and Abukuma metamorphic terranes Minor and trace elements of the grains in till and bedrock (K, Ca, Al, show an age peak around the Carboniferous to early Jurassic, wchich Si, Ti, Mg, Mn, Cr, V, Cu, Zn, Ni ) were measured using the Electron is agree with previous works [5,6; i.e. 330 to 184Ma and 280 to Probe Micro-Analysis. Various plots of these elements show that till 200Ma, respectively]. These lines of evidence may imply that the age of ca. 260 Ma shows a protoligh age for the metamoprhic samples generally form a cluster of very similar compositions that are terranes. Moreover, the Permian-Triassic detrital zircons from the different from magnetite in the Halfmile deposit country rocks Higo metamorphic terrane are characterized by positive εHf (T) especially because of their lower Si and higher Ti and V content. values (+7 < εHf(T) < +10) with high Th/U ratio (0.2 < Th/U < 0.5). Electron microscopy and Mineral Liberation Analysis (MLA) are Many Permian-Triassic granites are present within the Yangtze and also applied to study these till and bedrock grains to evaluate Cathaysia Blocks of the South China craton [7], and zircons with relationships between mineralogy, abundances and associations of positive εHf values were found in the Permian-Triassic felsic (T) minerals. Results indicate that up to 90 percent of magnetite in both rocks of the Emeishan large igneous province [8]. We concluded that the provenance for the Higo and Abukuma metamorphic terranes till and country rocks are polymineralic, and that detrital magnetite is may be indicative of the South China Block implying that they may Ti-bearing and is most often accompanied with titanomagnetite, not be the eastern extension of the North China-South China ilmenite and hematite. In the Halfmile deposit bedrock samples, in collision zone. contrast, magnetite is mostly in association with sulfide and/or silicate minerals. These heterogeneities in composition and mineral [1] Isozaki and Maruyama (1991) Jour. Geog. 100, 697-761. [2] associations of till and most of rock samples suggest that magnetite in till is largely derived from distant sources. Detrital magnetite shows Osanai et al. (2006) GR 9, 152-166. [3] Isozaki et al. (2010) Jour. the greatest chemical similarities with magnetite from nearby granitic Geog. 119, 999-1053. [4] Omori and Isozaki (2011) Jour. Geog. rocks.
120, 40-51. [5] Hiroi et al. (1998) Jour. Metamor. Geol. 16. 67-81. [6] Sakashima et al. (2003) Jour. Asian Earth Sci. 21 1019-1039. [7] Wang et al. (2005) Earth Planet. Sci Lett. 230, 339-354. [8] Xu et al. (2008) Geoch. Cosmoch. Acta 72, 3084-3104.

Mineralogical Magazine | www.minersoc.org 2060 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Geochemical characterization of Cu-isotope systematic of magmatic mineralized groundwaters in the PGE-Cu-Ni sulfide ores from the Aquitaine Basin (SW France): lateral Talnakh and Kharaelakh intrusions, and vertical variability of the Eocene Noril’sk Province (Russia) 1* 2 formations, hydrodynamic and KRESHIMIR N. MALITCH AND RAIS M. LATYPOV geochemical processes of acquisition of 1Institute of Geology and Geochemistry of the Uralian Branch the mineralization. of Russian Academy of Sciences, Ekaterinburg, Russia, [email protected] (* presenting author) 2Department of Geosciences, University of Oulu, P.O. Box 3000, Oulu, Finland, [email protected] 1,3* 2 ELINE MALCUIT , PHILIPPE NEGREL , EMMANUELLE PETELET- 2 3 3 GIRAUD , OLIVIER ATTEIA , MICHEL FRANCESCHI , ALAIN We have undertaken for the first time the examination of the Cu 3 DUPUY isotope composition of primary high temperature Cu-Ni sulfde ores

from world-class PGE-Cu-Ni sulfide deposits associated with the economic Talnakh and Kharaelakh intrusions and native copper ores 1BRGM, Regional Geological Survey Service Bordeaux, France, from the Noril’sk Province (Russia). Copper isotope ratios are 65 65 63 65 63 [email protected] (* presenting author) reported as δ Cu‰=(( Cu/ Cusample/ Cu/ CuNIST 976 standard)−1) x 2BRGM, Metrology Monitoring Analysis Department, Orleans, France, 103. The isotope measurements were carried out with an MC ICP- [email protected]; [email protected] MS (ThermoFinnigan Neptune) using sample-standard bracketing as 3EA 4592, ENSEGID - IPB, Pessac, France, outlined by Larson et al. [1]. 65 [email protected]; [email protected]; Main set of samples of this study form three major δ Cu 65 [email protected] clusters that well match δ Cu signatures of two distinct reservoirs as defined for iron meteorites and carbonaceous chondrites, 65 respectively [2-4]. The mean δ Cu value of massive sulfide ores at Talnakh forms the first cluster around zero ‰ (-0.1 ± 0.15 ‰, Section Heading: 22a. Tracing groundwater variability 65 respectively), close to the δ Cu signatures of the Bulk Earth and 65 iron meteorites. Similarly, the mean δ Cu value of disseminated In the sedimentary Nord Aquitaine Basin (SW France), the large sulfide ores at Talnakh forms the second cluster around –0.7 ‰ (– Eocene aquifer, mostly confined, is one of the main resources for 0.7 ± 0.4 ‰), matching that of the carbonaceous chondrites. The drinking water. In this aquifer, a large saline area has been identified, third cluster with the mean δ65Cu values, represented by massive and where the groundwaters show high values of mineralization and disseminated ores of the Kharaelakh intrusion (-1.52 ± 0.24 ‰ and - anomalous levels of critical elements, such as sulfates and fluoride, 1.6 ± 0.4 ‰, respectively) lie very close to the light-isotope end of the δ65Cu range expressed by the carbonaceous chondrites. A δ65Cu leading to difficulties of resource exploitation for drinking water supply. value measured in a sample and a replicate represented by native Geochemical and isotopic characterization of withdrawn groundwaters copper from the Arylakh deposit of the Noril’sk Province gave shows a common origin of the mineralization. indistinguishable result of -1.9±0.15 ‰. The Eocene aquifer formations include several geological layers, The determined δ65Cu variability is interpreted to represent a which have different lithological, mineralogical and hydrodynamic primary signature of the ores, though a magmatic fractionation of properties. Since the beginning of the century, many boreholes in the area copper isotopes and/or assimilation of the ore material from for drinking water supply have locally modified the natural water flows of external source (in case of the Kharaelakh ores) can not be ruled out. the system. Our investigation shows the need for a precise and detailed The study was supported by the Academy of Finland (grant No. knowledge of the vertical distribution of the hydrodynamic and 131619) and the Uralian Division of Russian Academy of Sciences geochemical properties of each layer. Indeed, the average concentration (12-U-5-1038). in the borehole water depends on the centimetre scale variation of water fluxes and concentrations. Geochemical models fully explain the [1] Larson et al. (2003) Chemical Geology 201, 337-350. composition of groundwaters across the study area and improve the [2] Luck et al. (2003) GCA 67, 143-151. understanding of geochemical processes taking place at the borehole [3] Luck et al. (2005) GCA 69, 5351-5363. [4] Wasson & Choi (2003) GCA 67, 3079-3096. scale.

To understand the acquisition of the groundwaters’ geochemistry,

it is necessary to consider the lateral and vertical variations in facies and

mineralogy, geochemical processes (mineral dissolution and/or

precipitation, phenomenon of diffusion in contact with low permeability

and mineralized layers) and local fluid mixing processes within the

borehole and its immediate surroundings.

Mineralogical Magazine | www.minersoc.org 2061 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Hafnium isotopic compositions of Genesis of alkaline magmas by Abyssal Peridotites from the reaction of MORB-eclogite derived Southwest Indian Ridge carbonated melt with lherzolite

1 1,2* 1 1 SOUMEN MALLICK , MICHAEL BIZIMIS ANANYA MALLIK* , RAJDEEP DASGUPTA AND VAIBHAV 1 1 MISHRA University of South Carolina, EOS, [email protected], [email protected] (* presenting author) 1Rice University, Houston, TX, USA (*[email protected])

We report Hf isotopic compositions of clinopyroxene mineral Ocean island lavas such as HIMU basalts are silica- separates from abyssal peridotites from the 9-25° E segment of the undersaturated [1] and present evidence of recycled oceanic crust in Southwest Indian Ridge (SWIR). Peridotites from 15.4° E are their mantle source. Partial melts of neither volatile-free peridotite plagioclase-free with low Na-Ti abundances and depleted chondrite nor subducted oceanic crust (MORB-eclogite) can explain the

normalized REE patterns in clinopyroxene (cpx) suggesting residual degree of silica-undersaturation and high TiO2 and high MgO, characteristics, The cpx show a limited variability and plot at the respectively of HIMU lavas. While reaction of MORB-eclogite radiogenic end of the MORB field in Nd-Hf isotope space (εNd ~ derived, volatile-free melts with peridotite produce alkalic basalts at 13.1, εHf ~ 18.5), consistent with the estimates for the DMM low melt-rock ratios [2], the reacted-melts are not low enough in

reservoir. However these peridotites are more radiogenic than SiO2 and Al2O3 and high enough in FeO* and CaO to explain most of spatially associated SWIR basalts, suggesting the presence of an the HIMU lavas. Here we explore whether MORB-eclogite derived

enriched component in the source of these basalts. A regression line CO2-bearing partial melts and volatile-free peridotite reaction can through these peridotites and co-located basalts in εNd-εHf space has a generate the required chemical attributes for primary HIMU-type 2 slope of 1.21 (R = 0.94), similar to the slope of mantle array, magmas. suggesting that the enriched component must lie within the mantle Reaction experiments were performed between lherzolite KLB- array. The un-radiogenic extension of the regression line in εNd-εHf 1 and two different MORB-eclogite-derived partial melts – (1) an

space passes close to the proposed local enriched endmember, similar alkalic melt with 8.5 wt.% CO2 (G2CPM1; [3]) and (2) a basaltic

to the Bouvet hotspot lavas. Assuming a Bouvet-like enriched andesite with 2 wt.% CO2 (G2CPM2) – at 1375 °C, 3 GPa, a composition in the source of the SWIR mantle, maximum 40% of the condition which is above the respective liquidii of both the melts but Hf budget in the basalts is contributed from the depleted peridotites below the solidus of peridotite. The amount of melt, mixed (15.4° E), which translates to a maximum of 10% enriched homogenously with peridotite, was varied from 8 to 50 wt.%. In all component in the basalt source. In contrast, peridotites from 9.98° E the experiments, the original melt underwent partial reactive

and 16.64° E have relatively high Na-Ti contents, high LREE/HREE crystallization, leading to CO2-enrichment in the reacted melt in ratios and are often plagioclase bearing, suggesting re-fertilization. equilibrium with a residue of garnet lherzolite to garnet-bearing The cpx from both locations plot towards the un-radiogenic end of olivine websterite. Reaction of G2CPM1-KLB-1 produced reacted

MORB field (εNd = 4.8-7.9 εHf = 9.9-14.2). They are however distinct melts which, on a volatile-free basis, show a decrease in SiO2 from

in Nd-Hf space and overlap with their co-located basalts. The above ~37 wt.% to ~35 wt.%, Al2O3 from ~7 wt.% to ~6 wt.%, FeO* from data is consistent with variable degree of equilibration between these ~17 wt.% to ~12 wt.%, Na2O from ~6 wt.% to ~3 wt.% and increase peridotites and local basalts. Model calculations show that 4% in TiO2 from ~6 wt.% to ~8 wt.%, MgO from ~15 wt.% to ~21 wt.%, addition of local basalts-like melt to the most depleted (15.4° E) local and Mg# from ~62 to ~75 with decreasing melt-rock ratio. The peridotites can explain the Nd and Hf isotopic compositions of re- reacted melts produced from 25-33 wt.% G2CPM2 have ~39 wt.% fertilized 9.98° E and 16.64° E peridotites, however, this estimate SiO2, 8.5-9.5 wt.% Al2O3, >10.5 wt.% FeO*, 15.4-16.5 wt.% MgO, does not match the REE patterns of the re-fertilized peridotites. This 9-10 wt.% CaO, and Mg# of 72-73. could indicate that local melts have reacted with a protolith, which is We demonstrate that carbonated MORB-eclogite derived mildly a residue of variable degree of melting but has an Nd-Hf isotope ratio alkalic melt evolves to more primitive, strongly alkalic similar to 15.4° E peridotites. compositions with variable melt:peridotite ratio. More importantly,

an andesitic melt with only 2 wt.% CO2 evolves to melts similar to The high Sm-Nd and Lu-Hf ratios of the depleted peridotites (15.4° melilititic, nephelinitic, and HIMU lavas. At a given MgO content, E) combined with their DMM-like Nd and Hf isotopes suggest recent the reacted melts evolved from G2CPM2 are a better match for depletion of a DMM – type mantle, likely related to recent melting alkaline ocean island lavas in terms of SiO2, Al2O3, FeO*, CaO, and underneath the SWIR. This observation is in contrast to the recently MgO as compared to partial melts of carbonated peridotites and reported highly radiogenic Hf isotopic compositions (εHf up to 291) of eclogites. We suggest that percolative flow of siliceous or mildly abyssal peridotites from the Gakkel Ridge, which have been alkalic carbonated melts in a subsolidus peridotitic mantle is a interpreted to reflect an ancient (> 1Ga) depletion and melt-rock widely occurring process, causing partial reactive crystallization of interaction processes. Our observation, together with Gakkel Ridge the original melts and leading to formation of primary alkalic peridotites indicates that earth’s mantle is more heterogeneous than magmas. The reacted melts have the potential to erupt as alkalic basalts suggest and investigation of Nd-Hf isotopic compositions of OIBs or to act as metasomatic flux to shallower source regions. abyssal peridotites from other areas will help us to better constrain the upper mantle composition. [1] Jackson and Dasgupta (2008) EPSL 276, 175-186. [2] Mallik and Dasgupta (in press) EPSL. [3] Gerbode and Dasgupta (2010) JPetrol 51, 2067-2088.

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high and low As occurrence in VICTORIA MANETA1* AND DON R. BAKER1 Murshidabad District, West Bengal: 1McGill University, Earth and Planetary Sciences, Montreal, Canada, India [email protected] (* presenting author), [email protected] 1 2 1 SANKAR M.S* , KATHERINE TELFEYAN , SOPHIA FORD , 3 2 ANDREW NEAL , TAHMINEH JADE HAUG , KAREN Introduction 2 1 JOHANNESSON AND SAUGATA DATTA According to the most prevalent models that explain the genesis of pegmatites, crystallization takes place after appreciable liquidus 1Kansas State University, Manhattan, KS, USA, [email protected] undercooling in a medium rich in fluxing components, such as H2O, B, F (* presenting author) and P [1, 2, 3]. The present study examines the potential of Li as another 2Tulane University, New Orleans, LA, USA fluxing agent and its effect on the formation of pegmatites. 3Virginia Water Resources Research Center, Virginia Tech, Pegmatitic textures are developed in experimental samples that Blackburg, VA, USA contain a starting material of common granitic composition, but enriched

in Li O, 3% seed crystals of K-feldspar, albite and quartz, and varying The assessment of incidence of arsenic (As) and the other major 2 ions is evaluated in the groundwaters of Murshidabad, West Bengal. amounts of H2O. The experimental procedure involves initially heating the This work is executed over an area of about ~497 km2. Water samples in a piston-cylinder apparatus to 1000˚C and 550 MPa for 1 hr, samples were collected from 39 hand pumped tube wells (~90- followed by cooling at 50˚C/min to temperatures from 600 to 900˚C and 110ft), 9 ponds and 6 irrigation wells (~60-80ft) along with 4 500 MPa and keeping those conditions constant for 100 hrs. sediment cores (~150ft) from these sites. Field sites are located The results show the formation of graphic intergrowths between east and west of the river Bhagirathi, a tributary of the river Ganges, quartz and K-feldspar that closely resemble the ones encountered in flowing N-S through Murshidabad. The western part of Bhagirathi pegmatites. Additionally, numerous K-feldspar crystals exhibiting river is mainly occupied by Suja formation, older alluvium of Pleistocene age (oxidized ferruginous sand, silt and clay with spherulitic and skeletal morphologies are formed in the experimental caliche), whereas the eastern part of the river is occupied by samples, suggesting rapid growth rates for the crystals that grow in the Li- Bhagirathi Ganga formation, newer alluvium of Holocene age (sand, enriched medium. The growth rates measured for the K-feldspar in the silt and clay). samples range from approximately 5 x 10 -11 m s-1 to 2 x 10-9 m s-1. Comparative study of major water quality parameters reveal high As Experiments conducted under the same conditions but with Li-free starting (10->500ppb) and low Mn (0.1-1.6ppm) in the areas like Beldanga, material do not exhibit the same tendency. Hariharpara (east bank of the river) while low As (0-30ppb) and higher Mn (0.2-8ppm) is found in Nabagram, Kandi (west bank of - the river). DO, NO3 and NH3 do not show appreciable variation among the high and low As areas and they range from 1.5-5ppm, 0- 2.7ppm and 0-0.06ppm respectively. TDS and conductivity do not show considerable variation among the high and low As areas and range from 0.001-6.2g/l and 2.6-988 μS/cm respectively. High As areas show a pH of 4.5-7.8 while pH in the low As areas is 5.1-8.2. Alkalinity values range from 10-18 mg/l at high and 10-180mg/l at 3- low As areas. PO4 values of high As areas range 0.2-11ppm and at low As areas the range is 0.3-1.3ppm. Cl- values are higher at low As areas (40-148ppm) and lower at high As areas (10-60ppm). Fe2+ values at high and low As areas are 0.05-6ppm and 0.1-1.4ppm respectively. Analyses show positive correlation of arsenic with 2+ 3- Fe , PO4 and TDS content in most of the high As areas, whereas the Mn and Cl- ions are negatively correlated with high As in most areas. During field work it is observed that there is good correlation Figure 1: Graphic intergrowth between K-feldspar and quartz developed between tube well platform color and high As concentration areas experimentally (2% added Li2O, 12% added H2O, P=500 MPa, T= 600˚C, which agrees with a recent study near Chakdaha, south of t=100 hrs) Murshidabad [2]. Stable isotope data from our sites show that groundwaters of this region are directly recharged by local Conclusion precipitation without significant evaporation [3]. Organic matter The experimental results indicate that the presence of Li in the system within aquifer sediments drive dissimilatory iron reduction reaction promotes the fast growth of crystals as well as the development of graphic and thus release As to the ground water [3]. quartz-feldspar intergrowths, both typical characteristics of pegmatites. [1] McArthur et al. (2012) ES&T 46, 669-676. [2] Biswas et al. (2012) ES&T 46, 434-440. [3] Datta et al. (2011) Geophys. Res. [1] Fenn (1986) American Mineralogist 71, 325-33. [2] Jahns & Burnham Lett., 38, L20404, doi: 10.1029/2011GL049301. (1969) Economic Geology 64, 843-864. [3] London (2008) Pegmatites, 347p.

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Response of methanogenic Oxygen and di-nitrogen (N2) communities to glacial-interglacial dynamics in the hypoxic zone of the climate changes in the Siberian Arctic St-Lawrence Estuary 1* 1,2 3 K. MANGELSDORF , J. GRIESS , A. GATTINGER 1 1* 2 3 AND D. WAGNER ROXANEMARANGER , MARK ALTABET , DENIS GILBERT , 4 5 4 ALFONSO MUCCI , LAURA BRISTOWE , BJORN SUNDBY 1GFZ Potsdam, Telegrafenberg, D-14473 Potsdam, Germany, 1Université de Montréal, Montréal, Canada, [email protected] (* presenting author) [email protected] (* presenting author) 2 AWI Potsdam, Telegrafenberg, D-14473 Potsdam, Germany 2University of Massachusetts at Dartmouth, Dartmouth, US 3 Helmholtz Centre Munich, Ingoldstädter Landstr. 1, D-85758 3Intitut Maurice Lamontagne, Mont Jolie, Canada Oberschleissheim, Germany 4McGill University, Montréal, Canada 5University Southern Denmark, Odese, Denmark Introduction

The Arctic has gained specific attention within the current Di-nitrogen (N2) is the terminal end product of denitrification debate on climate change. With the thawing of permafrost large and annamox, microbial processes that eliminates fixed-Nitrogen amounts of stored carbon become accessible again for microbial (N) from ecosystems. N loss is critical given the key role of N in degradation and will form a potential source for the release of CO2 coastal eutrophication. The Lower St-Lawrence Estuary (LSLE) is a and methane to the atmosphere having a positive feedback on the heavily stratified ecosystem, where persistent hypoxic conditions global warming. Therefore, it is of specific interest to understand have established and steadily increased over the last 80 years. In

the microbial driven greenhouse gas dynamics of the Siberian Arctic order to estimate fixed-N loss, we tracked the change in N2 and their response to glacial-interglacial changes in the past. concentrations along an isopycnal that progressively loses oxygen as Sample material was drilled on Kurungnahk Island (Russian- it moves landward from the Laurentian Channel into the LSLE. We

German expedition LENA 2002) located in the southern part of the found a very strong relationship between N2 excess and the O2

Lena Delta and in lake El’gyggytgyn (ICDP-project) in Northeast deficit in the LSLE, where excess N2 could be predicted linearly Siberia. The Kurungnahk samples comprise Late Pleistocene to from AOU with an r2=0.84. We estimate fixed-N losses from the

Holocene deposits, whereas the lake El’gyggytgyn samples cover change in N2 excess along the isopycnal of around 685-1370 μmol Middle to Late Pleistocene sediments. Samples were investigated N m-2 d-1. Compared with other methods estimating fixed-N loss, we applying a combine biogeochemical and microbiological approach. found that our lower estimate corresponds with the higher estimates determined in core incubations, whereas our higher estimate, Results and Conclusion corresponds to the lower estimate as predicted using N*. Using

The methane profile of the Kurungnahk core reveals highest excess N2 represents however the most integrative approach at the methane contents in the warm and wet Holocene and Late basin scale. Pleistocene (LP) deposits and correlates largly to the organic carbon (TOC) contents. Archaeol concentrations, being a biomarker for past methanogenic archaea, are also high during the warm and wet Holocene and LP intervals and low during the cold and dry LP periods. This indicates that part of the methane might be produced and trapped in the past. However, biomarkers for living microorgan- isms (bacteria and archaea) and microbial activity measurements of methanogens point, especially, for the Holocene to a viable archaeal community, indicating a possible in-situ methane production. Furthermore, warm/wet-cold/dry climate cycles are recorded in the archaeal diversity as revealed by genetic fingerprint analysis. In contrast to the results from the Kurungnakh core, in general the bacterial and archaeal biomarker profiles from the lake El’gygytgyn deposits reveal no distinct glacial-interglacial variability. This might be due to the fact that the overlying lake water buffers the temperature effect on the lake sediments which never became permafrost. The microbial abundance rather correlates to the TOC contents in the sediments forming the accessible carbon and energy source for the indigenous microbial communities. Also the diversity of methanogenic archaea, being still active in 400 ka old sediments, appears to vary with the organic carbon content. TOC-rich lake intervals seem to sustain a divers microbial ecosystem independent from glacial-interglacial climate cycles.

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during the injection and geological MARCANO N.1, OLDENBURG, T.B., MAYER, B1.

storage: an experimental approach AND LARTER S1.

1University of Calgary, Department of Geoscience, Calgary, Canada HERWIG MARBLER1, MICHAEL SCHMIDT1, KIRSTEN P. 1 1 1 ERICKSON , CHRISTOF LEMPP , AND HERBERT PÖLLMANN The growing trend of producing and refining large volumes of high- sulfur content petroleum leads to a need for exploring new ways of 1Martin-Luther-University Halle-Wittenberg, Institute for Geosciences, Von-Seckendorff-Platz 3, 06120 Halle, Germany meeting environmental regulations regarding the allowable sulfur [email protected] emissions and sulfur content of petroleum derivatives. Biodesulfurization is one of the new technologies currently being considered [1,2]. In this study, we use a natural biodegradation site Within the German national project COORAL* the behaviour of to examine the systematics of biodegradation of sulfur compounds in oil at reservoir conditions. The biodegradation of reservoir rocks from deep saline aquifers during the injection and alkylbenzothiophenes (alkylBT) and alkyldibenzothiophenes geological storage of CO2 with inherent impurities such as SOX (alkylDBT) were investigated in oil columns with progressively

and NOX is studied in laboratory experiments. Samples are taken biodegraded oil from top to bottom, using gas chromatography mass from sandstone outcrops of possible reservoir formations of spectrometry and sulfur isotopic compositions of bulk oil and oil fractions. The concentrations of alkylBT and alyklDBT decrease Rotliegend and Bunter Sandstones from the North German from hundreds of ppm to almost complete removal in biodegraded Basin. A combination of geochemical/mineralogical alteration oil columns with different ranges of biodegradation levels. The order experiments and geomechanical tests was carried out on these of sensitivity to biodegradation was found to be generally rocks to study the potential effects of the impurities within the dibenzothiophene (DBT), dimethylBT (DMBT) > trimethylBT (TMBT) > methylDBT (MDBT) > dimethylDBT (DMDBT). The CO pore fluid. Mineralogical alterations were observed within 2 preferential removal or preservation of some of the isomers gives the sandstones after the exposure to supercritical (sc)CO2 with insights into reaction mechanisms. Changes are also seen in

SOX/NOX and brine, mainly of the carbonatic, but also of the alkylated high molecular weight S and mixed SNO species observed silicatic cements, as well as of single minerals. Besides the using Fourier Transform Mass Spectrometry (FTICRMS), providing evidence for dealkylation of even very high molecular weight S partial solution effects, secondary mineral precipitations of bearing species. Despite multiple changes at the molecular level in carbonates and subsidiary silicates were observed within the the thioaromatic and NSO fractions, the bulk sulfur content of the oil pore space of the treated sandstones. The evaluation of the did not change significantly in the studied oil columns. The δ34S chemical composition of the reaction fluid during the course of values of bulk oil also did not change systematically with increasing biodegradation of sulfur compounds, while slight variations in the the autoclave experiments also indicate that dissolution and oil thioaromatic and asphaltene fractions may be related to the precipitation processes occur in the system fluid/rock/gas. The microbial alteration process. We propose a route forward for alterations affect the porosity and permeability of the treated studying the natural and industrial scale sulfur systematics of sandstones and also weaken their grain structure. Results of biologically altered crude oils.

geomechanical experiments on untreated samples indicate that

ŽŶĐĞŶƚƌĂƚŝŽŶ;ƉƉŵͿ the rock strength as well as the amount of injected scCO2 is Ϭ ϭϬϬ ϮϬϬ ϯϬϬ ϰϬϬ ϱϬϬ ϲϬϬ ϳϬϬ ϴϬϬ Ϭ influenced by the chemical composition of the pore pressure

fluid (scCO2 + SOX/NOX). After long-term autoclave treatment

with impure scCO , sandstone samples exhibit reduced strength 2 parameters and modified deformation behaviour compared to ϱ untreated samples. Dd ZĞůĂƚŝǀĞĞƉƚŚ;ŵͿ dDd d Dd Dd * The project “COORAL“ (“CO2 Purity for Capture and ϭϬ Storage”; acronym derived from German project title) is Figure 1: Progressive biodegradation of sulfur compounds in supported by the German Federal Ministry of Economics and progressively biodegraded oil towards the reservoir base. Technology on the basis of a decision by the German Bundestag. Third-party funding: Alstom, EnBW, E.ON, Vattenfall Europe, [1] Marcelis et al. (2003) Biodegradation 14 (3), 173-182. VNG. [2] Mohebali and Ball (2008) Microbiology 154, 2169-2183.

Mineralogical Magazine | www.minersoc.org 2065 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Making sense of large sets of XANES In situ Fe and multiple S isotope spectra analyses of an Archean pyrite nodule

1* 2 3 1,2 * 3 MATTHEW A. MARCUS ,THOMAS LENOIR ,PHOEBE J. LAM , JOHANNA MARIN-CARBONNE , CLAIRE ROLLION-BARD , 2 4 3, 1 ALAIN MANCEAU AXEL HOFMANN , EMILIE THOMASSOT , KEVIN MCKEEGAN , 5 6 ANDREY BEKKER AND OLIVIER ROUXEL 1Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley CA USA [email protected] 1 UCLA, Los Angeles, USA, [email protected], 2University of Grenoble 1 and CNRS Grenoble, France, [email protected] [email protected]; [email protected] 2Institut de Physique du Globe, Paris, France 3Department of Marine Chemistry and Geochemistry, Woods Hole 3 CRPG, Nancy, France, [email protected], Oceanographic Institution, Woods Hole, USA, [email protected] [email protected] 4University of Johannesburg, South Africa, [email protected] Natural materials are often heterogeneous, and must be sampled 5University of Manitoba, Winnipeg, Manitoba, R3G 2K4 Canada, at many points to be understood. We demonstrate new PCA-based [email protected] statistical techniques for estimating the number of end-member 6Universite de Bretagne Occidentale, Ifremer, Brest, France, components required to describe a dataset. Also, we have developed [email protected] a visualization tool which allows us to examine projections of the multidimensional dataset in such a way as to gain clues to the Studies of Fe and multiple S isotope composition of underlying statistical structure of the data. We show the example of sedimentary pyrites have placed important constraints on the the XANES analysis of Fe-bearing suspended marine particles from chemistry and the redox evolution of the ocean and the atmosphere two regions, 214 spectra from particles collected in the Northwest over the geological time [1,2,3]. Additionally, Fe isotopes have been Pacific, and 126 from the Southern Ocean. The data from the NW explored as a proxy for microbial metabolism [2]. Pyrite in black Pacific require more components to describe than those from the shales is predominantly formed either in the water column or during Southern Ocean. As shown in Figure 1, a well-chosen projection can early diagenesis close to the sediment-water interface and so let one identify distinct clusters of spectra having distinct features. potentially records chemical evolution of the ocean. Previous studies mostly used bulk samples, although individual pyrite nodules often show complex internal textures such as concentric lamination. Large isotopic variability within individual nodules has been shown for S isotopes [4] but not yet for iron isotopes. We have performed coupled situ Fe and multiple S isotope analyses of a pyrite nodule hosted by c. 2.7 Ga black shale from Zimbabwe. This mm-size nodule is composed of pure pyrite. Fe isotopes were measured with ims 1270 ion probes at both UCLA and CRPG [5]. We also performed multiple S isotope measurements Figure1: Stereogram of 3D projection of the first 6 PCA with the ion probe ims 1280 HR2 at CRPG. The measurements components of the NW Pacific dataset, with groups of spectra performed at CRPG and UCLA are in agreement with a colored in. Each dot represents one XANES spectrum, and nearby reproducibility better than 0.2 ‰ (2σ) in δ56Fe. Reproducibility for dots correspond to similar spectra. δ34S is ~ 0.2 ‰ (2 σ) and ~ 0.1 ‰ (2 σ) for Δ33S. The mean δ34S and δ56Fe values of this nodule are +2.9 ± 0.5 ‰ Figure 2: Averaged XANES and -1.08 ± 0.7 ‰, close to the bulk values of +3.2 ‰ and -1.46 ‰, spectra for the clusters shown respectively. Two profiles have been performed in one nodule and above. The colors correspond show large variations in both δ56Fe (~ 2.5 ‰) and δ34S (~5 ‰). The to those in Figure 1. δ56Fe profile shows 56Fe enrichment in the rim relative to the core. The δ34S profile shows large isotopic variation that have no Least-squares fits to the systematic relationship with the location. Δ33S values are negative in Norm. absorbance Norm. spectra shown in Figure 2 the core and positive in the rim. The pyrite nodule was likely formed indicate clays+poorly- in a closed system during diagenesis, under reducing conditions but crystalline Fe oxyhdroxide also record some iron oxidation in the water column. S isotopes 7100 7150 7200 7250 7300 (red), oxidized phyllosilicates reflect mixing and different reactivity of two sulfides pools (sulfate Energy (eV) (green), biotite+chlorite+clay and elemental sulfur photochemically produced in the atmosphere) (cyan) and magnetite+Fe2+ silicate+ Fe oxyhdroxide (purple). in sediments. Coupled S and Fe isotope composition at μm-scale Conclusion provides new insights into Archaean ocean chemistry. Statistical tools can allow one to see patterns in data which [1] Rouxel et al. (2005) Science, 307, 1088-1091, [2] Johnson et al. would otherwise be invisible when examining spectra individually. (2008) Annu. Rev. Earth Planet. Sci. 36, 457-493, [3] Farquhar et al. (2000), Science, 298, 756-758, [4] Kamber and Whitehouse We demonstrate how a complex XANES dataset can be simplified (2007), Geobiology, 5, 5-17, [5] Marin-Carbonne et al. (2011) so that important characteristics such as dominant minerals and their Chemical Geology, 285, 50-61 distribution may be identified.

Mineralogical Magazine | www.minersoc.org 2066 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts FREZCHEM: A geochemical model Post OIS6 climate-change records in the for cold aqueous solutions Lower Mississippi Valley and mid- 1* GILES M. MARION Atlantic Coastal Plain 1* 2 1Desert Research Institute, Reno, Nevada, USA, HELAINE W. MARKEWICH , MILAN J. PAVICH , DOUGLAS A. WYSOCKI3, RONALD J. LITWIN2 [email protected] (*presenting author) 1U.S. Geological Survey, Atlanta, GA, [email protected] FREZCHEM Model (* presenting author) 2 U.S. Geological Survey, Reston, VA, [email protected] , FREZCHEM is an equilibrium chemical thermodynamic model [email protected] parameterized for concentrated electrolyte solutions (to ionic 3 U.S. Department of Agriculture, National Soil Survey Center, Lincoln, strengths = 20 molal) using the Pitzer approach [1] for the NE, [email protected]

temperature range from –100 to 25°C (CHEMCHAU version has Published and on-going investigations allow comparison of post OIS6 temperature range from 0 to 100°C) and the pressure range from 1 chrono- and pedo-stratigraphic and palynologic records in the Lower to 1000 bars [2]. The current version of the model is parameterized Mississippi Valley (LMV) and mid-Atlantic Coastal Plain (MACP) of the unglaciated USA. Data indicate that in both regions W-NW winds were for the Na-K-NH -Mg-Ca-Fe(II)-Fe(III)-Al-H-Cl-ClO -Br-SO - 4 4 4 responsible for loess and eolian-sand deposition and that in both regions NO3-OH-HCO3-CO3-HSO3-SO3-HS-S-CO2-O2-CH4-NH3-SO2-H2S- depositional periods were coeval with Northern Hemisphere glaciations

Si-H2O system and includes 115 solid phases including ice, 16 and characterized by boreal environments. The LMV was the major meltwater conduit associated with the chloride minerals, 36 sulfate minerals, 16 carbonate minerals, six Laurentide Ice Sheet (LIS). Loess dominates the OIS6, 3, and 2 LMV sulfite minerals, five solid-phase acids, four nitrate minerals, seven stratigraphic record. Sand dunes are a minor component. The Susquehanna perchlorates, six acid-salts, five iron oxide/hydroxides, four and Delaware rivers were conduits for glacial meltwater that had an impact aluminum hydroxides, two silica minerals, two ammonia minerals, on the Chesapeake Bay area of the MACP. Eolian deposits are more spatially and temporally restricted in this area than in the LMV and are two gas hydrates, two bromide sinks, and one sulfide mineral most prevalent within 300 km of the glacial border. Eolian sand dominates (pyrite). Fortran codes and an Internet working model are available the OIS 3 and 2 MACP stratigraphic record. at http://frezchem.dri.edu. Applications for FREZCHEM can be very diverse because of its extensive physical ranges. For example, if ammonia/ammonium and methane are prevalent on Titan, that can lead to interesting chemistries over the temperature range of 173-273 K (Fig. 1).

Notice that SO4 largely precipitates, but CH4 (aq) increases, which may be why methane is a major component on the surface of Titan where the temperature is 94 K.

Figure 1: Age data for loess, eolian sand, and paleosols from the LMV[1] and the mid- Atlantic region[2][3][4].

Palynologic and paleowind data, along with the chrono- and pedo- Figure 1. The chemical compositions as temperature decreases stratigraphic records, are adequate to allow preliminary comparisons of from 273 to 173 K beneath Titan surface. Arrows on the X-axis late Pleistocene climates in the two regions. indicate when solid phases start to precipitate. [1] Markewich et al. (2011) Geo. Soc. Am. Bull. 123, 21-39. [2] Lowery et [1] Pitzer (1991) Activity Coefficients in Electrolyte Solutions al. (2010) Quaternary Sci. Rev. 29, 1472-1480. [3] Pavich et al. (2010) CRC Press. [2] Marion & Kargel (2008) Cold Aqueous Planetary Geo. Soc. Am. Abs. with Prog.42, 231. [4] Wysocki et al. (2010) Soil Sci. Geochemistry with FREZCHEM Springer. Soc. Am. http://a-c-s.confex.com/crops/2010am/webprogram/Paper60303.html.

Mineralogical Magazine | www.minersoc.org 2067 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Analysis of 33 Uranium Ore The Terceira Rift, Azores: a melt Concentrate Samples: A Case Study inclusion study of submarine lavas 1* 2 3,4 in Nuclear Forensics A.F.A. MARQUES , S.D. SCOTT , P. MADUREIRA , P. 4 4 5 1 1 1 CONCEIÇÃO , N. LOURENÇO , AND C.J.P. ROSA NAOMI MARKS *, IAN D. HUTCHEON , MARTIN ROBEL , LARS 1 1 E. BORG CREMINER (LARSyS) Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal, [email protected] (* presenting 1Lawrence Livermore National Lab, USA, [email protected] (* author) presenting author) 2University of Toronto, Dept. of Geology, Toronto, Canada

3Centro de Geofísica de Évora / Dept. Geociências da Universidade Nuclear forensics is a scientific discipline interfacing law de Évora, Évora, Portugal enforcement, nuclear science and non-proliferation. Information on 4EMEPC – Estutura de Missão para a Extensão da Plataforma the history and on the potential origin of intercepted nuclear Continental, Lisbon, Portugal material can be obtained through nuclear forensic analysis. Using 5LNEG – Laboratório Nacional de Energia e Geologia, Lisbon, commonly available techniques of mass spectrometry, microscopy Portugal and x-ray diffraction, we have gained insight into the processing and

origin of a suite of uranium ore concentrate (UOC) samples. The 33 UOC samples are in the form of ammonum di-uranate The Azores plateau, a bathymetric high seated on an anomalous (ADU). The sample suite is thought to represent a time series mantle domain is located in the Azores Triple Junction where the collected at the same location over a number of years. The rare American, EUR and AFR lithospheric plates meet. The cause for earth element (REE) patterns match the REE patterns for these anomalies is controversial but many authors consider the phosphorites reported in [1], implying that the samples are derived presence of an anomalously hot/wet enriched mantle probably from a phosphorite deposit (Figure 1). The REE patterns are fairly supplied by a plume [1]. The origin, size and present location of the consistent throughout the series, although absolute concentrations plume is under debate but an area near Terceira is the favoured of REEs decrease through the time sequence (Figure 1) suggesting plume centre [2]. The Terceira Rift (TR) defines the EUR/AFR plate improvments in metallurgy with time. boundary of the Azores triple junction. The TR is a 550 km long, generally ESE trending line of volcanic massifs (e.g. São Miguel, D. 10000 João de Castro, Terceira and Graciosa) alternating with deep basins (e.g. Hirondelle basin). The latter are interpreted to be volcanically 1000 unfilled rift valley segments [3]. Vesicular, porphyritic basalts were

100 sampled along the Terceira Rift during Portuguese scientific cruises (EMEPC 2007-2009). Initial studies focused on the adjacent areas 10 Don João de Castro - DJC (submarine volcano) and Hirondelle - Hir REE/ Chondrite (basin). Major and trace element data of phenocrysts (olivine, 1 Early clinopyroxene, plagioclase), groundmass and exposed melt inclusions in these vesicular lavas depict only slight differences 0.1000

Middle between the two sites although DJC samples have somewhat higher Late 0.0100 Fo and Mg# in olivine and clinopyroxene, respectively. Chondrite- normalized REE data indicate that groundmass material is LREE- 0.0010 La Ce Pr Nd Sm Eu Gd Tb Dy Ho Er Tm Yb Lu enriched in both Hir and DJC lavas. Exposed melt inclusions (MI) Figure 1: Chondrite normalized REE patterns for the suite of UOC show similar REE patterns compared to their hosts. Clinopyroxene samples. in both sites displays L-MREE enriched, HREE depleted sinusoidal The U purification process appears to be OPPA solvent patterns. MI were found in olivine, clinopyroxene and plagioclase extraction based on the form of the UOC (as ADU). The first few phenocrysts. MI are glassy to completely opaque and devitrified, samples in the time series have higher concentrations of almost all with one or more bubbles, and sulfide globules (SG). SG are impurity elements, and lower concentrations of U, than subsequent spherical, depict two-phase lamellar intergrowths of Fe-Ni and Cu- samples. Some of the later samples have on up to 40% higher Fe phases, and are ubiquitous in DJC and Hir lava samples. Some concentrations of alkali earths and alkali metals, indicating slight lavas display SG within clinopyroxene-hosted MI and dispersed in variations in feedstock. The consistency in trace element patterns, the groundmass. Preliminary data suggest that lavas found in these however, suggests the samples are derived from geologically related areas of the Terceira Rift were sulfur-saturated in different stages of ore bodies. This study illustrates one way in which nuclear forensic their evolution; during early fractionation and prior to eruption. The analysis can provide insight into the ore geology and production and geochemistry of melt inclusion will contribute to the understanding purification methods used to produce UOC. of mantle source, melting and mixing processes in the Terceira Rift, Azores. [1] Varga (2010) Talanta 80, 1744-1749. This work performed [1] Asimow et al. (2004) Geochem. Geophys. Geosyst. 5, Q01E16, under the auspices of the U.S. DOE by Lawrence Livermore [2] Jean-Baptiste et al. (2009) EPSL 281, 70-80. National Laboratory under Contract DE-AC52-07NA27344. [3] Vogt (2004) EPSL 218, 77-90.

Mineralogical Magazine | www.minersoc.org 2068 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Sorption of Lanthanides and trivalent Comparison of grain size and BET actinides on montmorillonite in the presence and absence of carbonate surface area trends in modern glacial 1* 1 1 and non-glacial fluvial sediments as a M. MARQUES FERNANDES , B. BAEYENS , R. DÄHN , T. 2 1 STUMPF AND M. H. BRADBURY proxy for deep-time climate 1 Paul Scherrer Institut, Villigen, Switzerland, *[email protected] 1* 1 2 KRISTEN R. MARRA , MEGAN E. ELWOOD MADDEN , Karlsruher Institut für Technologie, Eggenstein-Leopoldshafen, 1 1 GERILYN S.SOREGHAN , AND ALLISON R. STUMPF Germany 1ConocoPhillips School of Geology and Geophysics, University of The fate of released RNs in a deep geological radioactive waste Oklahoma, [email protected] (* presenting author)

repository is primarily controlled by sorption/desorption processes

onto mineral surfaces. Clay minerals are major constituents in both Chemical and physical weathering in sediments is highly the man-made engineered barriers and in the argillaceous host rock contingent upon erosion rates and climatic variables (temperature formations currently being considered for a deep high level and precipitation). Sediment grain size and surface area also impose radioactive waste (HLW) repository in Switzerland. In the near-field critical controls on mineral-water reaction rates, where finer grain of HLW repositories, reducing conditions are expected to prevail sizes are correlated to higher surface areas and thus increased and the RNs are present in their lowest oxidation states. Trivalent chemical weathering, even in glacial environments [1]. However, actinides such as Am(III), Cm(III) and Pu(III) make a significant sediment surface area is generally not evaluated or reported for contribution to the radiotoxicity of HLW. In natural environments, natural systems. Here we document grain size and BET surface area the predominant aqueous phase reactions of lanthanides and trivalent trends within the mud fraction (< 63 μm) of proximal fluvial actinides (Ln/An(III)) are hydrolysis and complexation with sediments in a cold-arid, glacial (Clark Glacier Stream, Wright dissolved inorganic ligands, such as carbonates. Such complexation Valley, Antarctica) and a warm semi-arid, non-glacial (Blue Beaver reactions could potentially decrease the metal ion sorption and thus Creek, Wichita Mountains, Oklahoma) environment. Both systems 2 increase the migration rates of these RNs. are of similar basin drainage size (40 km ), relief (360-465 m), and The sorption of Ln/An(III) on montmorillonite in the absence bedrock lithology (granitoid). and presence of dissolved carbonate was investigated by a In the polar glacial transect, the mud fraction coarsens with combination of different approaches. Batch sorption experiments, distance along transect, with a corresponding decrease in BET surface complexation modelling, Time-Resolved Laser surface area, indicating rapid dissolution of fines. In the non-glacial Fluorescence Spectroscopy (TRLFS) and Extended X-ray transects, grain size decreases downstream while surface area Absorption Fine Structure (EXAFS) spectroscopy were applied to increases, reflecting precipitation of clay-sized weathering products. investigate the uptake of Ln/An(III) on montmorillonite at low Aqueous chemistry of stream water samples collected surface loadings (d 3 mmol˜kg-1). The macroscopic sorption simultaneously with stream sediments supports the conclusion that experiments showed that the presence of carbonate leads to a silicate dissolution dominates in the glacial environment, whereas pronounced decrease of Ln/An(III) uptake on montmorillonite. incongruent chemical weathering of silicate phases is predominant Modelling the experimental data with the 2SPNE SC/CE sorption the non-glacial environment. The occurrence of opposing trends model under the assumption that carbonate complexes do not sorb, within climatically distinct settings indicates that the production and clearly under predicted the experimental data, suggesting the fate of fine-grained sediments may be diagnostic of glacial and non- formation of ternary Ln/An(III)–carbonate surface complexes. In glacial regimes and potentially evident in the rock record. order to verify this assumption, EXAFS and TRLFS were applied. Additionally, systematic quantification of sediment surface areas The differences in the TRLFS spectra obtained for samples in the provides critical constraints on evaluating the effect of chemical presence and absence of carbonate i.e. red-shift of excitation and weathering on modern and deep-time global carbon cycles. emission spectra, as well as the increase of fluorescence lifetimes, unambiguously showed the influence of carbonate, and were fully consistent with the formation of Ln/An(III)(III) surface species involving carbonate complexes. The EXAFS parameters derived by fitting the spectra of the carbonate free sample were consistent with [1] Anderson (2005) Geomorphology 67, 147-157. bond lengths from Am-O and Am-Si/Al backscattering pairs, and clearly indicated that An(III) forms inner sphere complexes at the montmorillonite surface. The EXAFS parameters obtained by fitting the spectra of the sample prepared in the presence of carbonate was consistent with the formation of an An(III) complex at the montmorillonite surface with 1 to 2 carbonate groups. The application of EXAFS and TRLFS clearly supported the macroscopic sorption experiments and modeling results and confirmed the

formation of ternary Ln/An(III)-CO3 complexes at the montmorillonite surface.

Mineralogical Magazine | www.minersoc.org 2069 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Sulfur isotopes in high-pressure rocks Warm Arctic Peatlands – Future 1* 1 HORST R. MARSCHALL , NOBUMICHI SHIMIZU Methane Factories? 1WHOI, Woods Hole, MA, USA, [email protected] (* CHRIS MARSHALL*1, DAVID J LARGE1, WILL MEREDITH1, presenting author), [email protected] COLIN E SNAPE1, BARUCH F SPIRO2 AND MALTE JOCHMANN3*

1 Chemical &Environmental Engineering, University of Nottingham, Models of the global sulfur cycle are afflicted with a lack of [email protected] knowledge on the efficiency and isotopic effects of subduction 2Natural History Museum, London processes. Primitive undegassed basalts, as well as sulfide [email protected] inclusions in mantle xenoliths and in eclogite-type diamonds display 3Store Norske Grubekompani AS Longyearbyen a relatively large variation in δ34S (Seal, 2006) providing evidence [email protected] (* presenting author) for significant mantle heterogeneities in S isotopes. It has been

speculated that recycling of sulfur in subduction zones is in part Palaeocene Arctic coal represents a unique terrestrial record of responsible for these variations. However, models of the deep peatland processes and carbon storage during the last period of Arctic mantle sulfur cycle ignore any processes operating during warmth. Modern high latitude warming is accelerated when subduction. Estimates on the subduction input into the mantle are compared to global averages [1] indicating future Arctic peatlands reduced to using the compositions of un-metamorphosed oceanic may bear closer resemblance to Palaeocene peatlands than those seen rocks, because little is known on the behavior of sulfur and sulfur at the present time.The Svalbard coals formed around 60Ma at isotopes during high-P metamorphism and subduction zone latitude 68°N. Previous studies of mid-latitude Paleocene coals, [2] devolatilization. This study aims to close this gap, and investigates provide evidence of significant methanogenic communities within the S isotope composition of sulfides in natural high-P rocks. peatlands before and during the PETM event. Modern high latitude Sulfur isotope analyses were conducted by SIMS on pyrite and methane fluxes have been linked to polar stratospheric cloud chalcopyrite. Based on petrographic evidence, the sulfides were formation [3] and accelerated Arctic warming This study aims to use attributed to formation during two contrasting stages of the organic petrology and geochemistry to find evidence of such methane subduction-exhumation cycle: (1) sulfides formed prior to or during fluxes in Palaeocene, Svalbard and study the implications for modern subduction, and (2) sulfides in revolatilization zones formed during peatlands exhumation, probably by fluids released from the subducting slab. The first type bears on the isotopic composition of sulfur in different lithologies subducted to various depths, while the second type complements these data by reflecting the composition of fluids released from the slab. Preliminary data from various samples investigated so far include both types of sulfide from various localities (Cycladic blueschist belt, Greece; Zermatt-Saas Fee, Italian Alps; Western Gneiss Region, Norway; New England Fold belt, Australia; Franciscan fm., California) and present the following picture: Figure 1: M/z 205 gas chromatograms showing 2 & 3 Methyl- (i) δ34S values of prograde pyrite and chalcopyrite in eclogites hopanes in Svalbard coal extracts. are mainly positive: ~0 to +14 ‰, although some individual pyrite

grains show negative values down to –3.4 ‰. The grains are typically Total hopane concentrations (bacterial biomarkers) in Svalbard coals unzoned in S isotopes. are 45- 125mg/g extract indicating the coals are massively enriched (ii) prograde pyrite and chalcopyrite from a high-P in microbial lipids compared to other source rocks (<2mg/g extract 34 metasediment shows grains unzoned in δ S with values as low as – [4]). High detrovitrinite contents in the Svalbard coals also indicate 31 ‰. high levels of biodegradation for the latitude. This is probably a 34 (iii) δ S values of retrograde pyrite show a heterogeneous feature of high peatland seasonality with winter productivity lowered picture with unzoned grains having negative (as low as –21 ‰) or but temperatures sufficient, to allow continued biodegradation. positive values, as well as mm-sized grains with ~8 permil δ34S core- Methanotrophic biomarkers, 3-methyl hopanes (figure 1) are to-rim zonation. enriched (1.26mg/g extract) significantly compared to other source The results obtained to date suggest that altered igneous crust rocks (<300μg/g extract, [4]). This increase is thought associated carries a positive δ34S signal down to the UHP eclogite stage, while with the general increases in biodegradation shown by the hopanes. sediments are probably depleted in 34S. Evidence for high-δ34S fore- This is reflected by 3Me/Total Hopane ratios of 2-3%, which are arc fluids is found in retrograde pyrite. However, some retrograde consistent with other source rocks [4]. Consequently, if future Arctic pyrite shows very low δ34S values, which may be related to peatlands evolve similarly, biodegradation would be expected to metasedimentary sources in the slab. High-P serpentinites and increase rapidly, increasing the Arctic terrestrial carbon flux and harzburgites will be one of the future foci of this ongoing study into accelerating subsequent high latitude warming. the subduction zone sulfur cycle. [1] Holland & Bitz (2003) Climate Dynamics 2, 221-232 [2] Pancost et al. (2007) Nature 449, 332-335. [4]Sloan & Pollard (1998) [1] Seal RR (2006) Sulfur isotope geochemistry of sulfide minerals. Geophysical Research Letters 25, 3517-3520 [4] Farrimond et al. MSA Reviews in Mineralogy and Geochemistry, 61: 633–677. (2004) Geochimica et Cosmochimica Acta 68, 3873-3882.

Mineralogical Magazine | www.minersoc.org 2070 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Uranium incorporation during iron Advanced Geological Applications (oxyhydr)oxide crystallisation at Using XRF Elemental Mapping and hyperalkaline pH Small Spot Analysis Al Martin 1*, Didier Bonvin 2, Chris Shaffer 3, Kurt Juchli4 T. A. MARSHALL1* , G.T.W. LAW2, K. MORRIS2, 1 J.F.W. MOSSELMANS3 AND S. SHAW1. Thermo Scientific, The Woodlands, TX, USA, [email protected] (* presenting author) 1ESSI, School of Earth and Environment, University of Leeds, UK. 2Thermo Fisher Scientific, Ecublens, Switzerland, [email protected] (*presenting author) [email protected] 2RCRD and CRR, Schools of Earth, Atmopsheric and Environmental 3Thermo Fisher Scientific, Ecublens, Switzerland, Sciences and Chemistry, The University of Manchester, UK. [email protected] 3Diamond Light Source, UK. 4Thermo Fisher Scientific, Ecublens, Switzerland,

[email protected] Geological disposal of the legacy of radioactive wastes stored at Earth's surface is now the accepted management pathway for these

materials and is a task of importance for nuclear power generating

countries. In many radioactive waste disposal scenarios, intermediate level wastes are grouted and the geological disposal facility (GDF) will have cement present as a ubiquitous engineering material. 23d. General geochemistry Further, cementitious grouts have been considered as backfill for the Geochemical and R&D applications offer interesting GDF. Therefore, post-closure leaching of cementitious materials in a analytical challenges in the sense that these materials can represent a GDF is expected to create hyperalkaline conditions in and around the repository. These high pH fluids will react with the repository wide elemental coverage, wide concentration ranges and varied components and host rock, resulting in mineral alteration and sample matrices and sizes. Analytical performance of wavelength crystallisation. Iron within the host rock derived from the alkaline dispersive X-ray fluorescence (WDXRF) instruments is being breakdown of Fe-bearing silicate minerals (e.g. biotite, chlorite) or constantly advanced in order to cope with such challenges. corrosion products formed within the repository will form iron (oxyhydr)oxide minerals. The formation and re-crystallisation of While traditionally WDXRF technique has always these reactive minerals, which may sequester radionuclides through demanded homogeneous samples, the latest developments permit reduction to less soluble forms and/or incorporation to more stable analysis of small spots down to 0.5mm as well as mapping of a secondary iron oxide phases [1], may prove key to the fate of selected area of a sample. These new possibilities open up the radionuclides in such environments. To evaluate the signficance of these processes, ferrihydrite was WDXRF technique to heterogeneous samples where segregations,

crystallised under CO2-free oxic and anoxic conditions, in two U(VI) defects or inclusions can now be determined. Coupling these amended synthetic cement leachates, representing early (pH 13.1) capabilities with standardless analysis permits quantification of up to and late (pH 10.5) stage cement evolution for a cementitious ILW GDF. Under oxic conditions ferrihydrite crystallised to hematite (pH 79 elements of the periodic table on selected points of the sample. 10.5) and goethite (pH 13.1). Under anoxic contitions in both In this presentation, several examples will be presented and leachates, and in the presence of Fe(II), ferrihydrite crystallised to finally tied into one thorough application in which the power and magnetite. X-ray Absorption Spectroscopy was used to characterise flexibility of new WDXRF instruments are fully exploited. uranium association with each of the iron (oxyhydr)oxide phases during the crystallisation reactions. Under oxic conditons at pH 10.5, U(VI) rapidly (hours) sorbed to the ferrihydrite. Thereafter, during crytallisation, analysis indicates that U(VI) became structually incorporated in the hematite lattice. At pH 13.1, U(VI) remained 0.22 μm soluble and did not sorb to either ferrihydrite or goethite. Under anoxic conditions, in both leachates, uranium was rapidly (minutes) removed from solution as the ferrihydrite crystallised to magnetite (catalysed by Fe(II) in solution). Here, U(VI) was reduced to U(IV) and XAS analysis suggests it was directly substituted into octhedral sites of the magnetite structure. These data have significant implications for the safety case for uranium behaviour in alkaline conditions in a GDF and in contaminated land scenarios. Details of uptake and bonding mechanisms of uranium in the iron oxide phases will be presented.

[1] Boland et al. (2011) Environ. Sci. Technol. 45, 1327-1333.

Mineralogical Magazine | www.minersoc.org 2071 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Chemical weathering fluxes through a Isotopic insight into volcanic sulfate coastal aquifer, the Pingtung Plain, formation in the troposphere. 1(*) 2 1 southwest Taiwan ERWAN MARTIN , SLIMANE BEKKI , CHARLOTTE NININ , 3 1 1 1 AND IYA BINDEMAN . CAROLINE MARTIN *, ALBERT GALY , NIELS HOVIUS , MIKE 1 2 3 1 BICKLE , IN-TIAN LIN , MING-JAME HORNG , DAMIEN ISTEP-UPMC, Paris, France. [email protected], 4 1 5 [email protected] CALMELS , HAZEL CHAPMAN AND HONGEY CHEN 2LATMOS-IPSL, Paris, France. [email protected] 1Dept. Earth Sciences, University of Cambridge, UK, 3Dprt of Geological Sciences, Univ. of Oergon, Eugene, USA. [email protected] (* presenting author) [email protected] 2 Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, We present analyses of oxygen and sulfur isotopic composition [email protected] of sulfate extracted from volcanic ash collected near volcanoes 3Water Resources Agency, Ministry of Economic Affairs, Hsin-Yi Road, Taipei, Taiwan few hours or days after eruptions. This study is based 10 volcanic 4Institute de Physique du Globe, Paris, France, [email protected] eruptions that occurred from the equator to 65°N. 5Dept. of Geosciences, National Taiwan University, Taipei, Very significant variability is observed in the dataset with SO4 [email protected] concentration ranging from 350 to 7500ppm, G18O from 0.2 to

17 34 Tracing groundwater offshore has resulted in a wide range of 13.2‰, Δ O from -0.14 to 0.35‰ and G S from 3.9 to 10.5‰. 34 submarine groundwater discharge (SGD) estimates for specific While G S of volcanic sulfate is expected to reflect processes marine locations, but complementary, similarly-focused studies that mainly occurred in the volcanic plume, the O-isotopes clearly measuring potential throughput on land are few. We analysed the trace the oxidation pathways of volcanic SO2 in the atmosphere and waters from 43 wells at varying depths through a 264 m window in more specifically in the troposphere for our samples. 17 18 the Pingtung Plain for major dissolved cations, anions, dissolved Assuming that Δ O = 0‰ and G O = 5-7‰ in SO2 coming out SiO2, and stable isotopic composition of oxygen and hydrogen of from the volcanoes, the resulting sulfate Δ17O would be signifi- water, and used Darcy’s Law to compute their subsurface fluxes. cantly different from 0‰ only if a substantial fraction of SO was Compared to chemical flux estimates from the adjacent Kaoping 2 River, results show that 1.1 to 12.3 % of combined surface runoff oxidized via mass-independent fractionating oxidation pathways 34 and potential subsurface discharge to the ocean can be attributed to (reaction with O3 or H2O2). On the other hand, the G S of sulfate groundwater-derived weathering fluxes. Estimated propagated errors was expected to fall within the initial volcanic SO2 range, which is at 2σ on subsurface fluxes are ± 30 % assuming the hydraulic G34S = 6-8‰. The fluctuations of about 2‰ outside this range in conductivity is known by ±10 %. Multi-year daily hydraulic head data gives the direction of groundwater flow through the plain, and the measured sulfate may reflect some Rayleigh distillation proc-

indicates that pumping has led to episodic reversals of flow, esses in the volcanic plume. facilitating seawater intrusion in the near-coast aquifer. The different volcanic events analysed here correspond to dif- Hydrological connectivity exists throughout the drilled depth of the ferent environmental conditions (latitude, season…) for the oxida- basin, whereas chemical gradients suggest that stratified flow is in + operation, with up to a two-fold increase in silicate-derived Na seen tion of volcanic SO2. We analyse, via 3-D chemistry-transport

in deeper horizons as compared to the near surface. For all ions model calculations, the expected levels of SO2 oxidants in the except Ca2+ and SO 2-, the average concentrations of dissolved 4 atmospheric column above the studied volcanoes. For each erup- species in the distal groundwaters exceed those of the river, ranging 17 17 from a factor of 1.2 in the case of Li+, K+ and Mg2+ to 5.4 in the case tion, we are able to compare the measured Δ O with the Δ O 2+ 2+ of Ba . At 12.3 %, the relative groundwater flux of Ba exceeds estimated in sulfate produced by SO2 oxidised in model-calculated that of all other elements by at least a factor of two. Furthermore, background conditions. Ba2+ concentrations in the near surface coastal aquifer exceed those Our results indicate that, for the vast majority of the cases, the in deeper horizons by up to a factor of 7.9. The observation of increasing Ba2+ in the shallow subsurface could be accounted for by main oxidant for volcanic SO2 in the troposphere is OH radicals 2+ a desorption mechanism. However, the correlation of Ba and ionic or, at least, that SO2 is not significantly oxidised via a mass- strength is poor, requiring an additional mechanism that could affect independent fractionating channel. OH in the very dry stratosphere Ba, (additional dissolution of Ba-bearing phases), and/or the ionic carries a substantial mass-independent isotopic anomaly while in strength (~Na+), such as reverse weathering. Results suggest that, with the exception of Ba2+, submarine groundwater chemical fluxes the humid troposphere this anomaly is thought to be lost through

into the Taiwan Strait are modest in comparison to those related to isotopic exchanges with H2O. It is likely that the low pH of vol- surface runoff. If reverse weathering is promoted in seawater- canic aerosol clouds could reduce very significantly the heteroge- intruded aquifers, the silicate weathering fluxes in the Pingtung Plain neous oxidation via the mass-independent O and H O in the tro- would still be underestimated after the incorporation of SGD. 3 2 2 posphere.

Mineralogical Magazine | www.minersoc.org 2072 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Fluid evolution along a cross section Evidence for the accumulation of through the Central Alps, Switzerland heterocyclic N compounds in 1* 1 1 K. MARTINEK , T. WAGNER , M. WÄLLE , temperate forest soils as a function of

1 AND C.A. HEINRICH depth

1 Geochemistry and Petrology, ETH Zurich, Clausiusstrasse 25, CH- CARMEN ENID MARTÍNEZ1* , JOSEPH DVORAK2 8092 Zürich, Switzerland, [email protected] 1The Pennsylvania State University, Department of Crop and Soil

Sciences, University Park, PA, USA, [email protected] (* The classical Alpine fissure veins, large cavities lined by presenting author) occasionally giant quartz crystals, occur in regionally 2 Brookhaven National Laboratory, National Synchrotron Light metamorphosed rocks in the Central Alps. They record important Source, Upton, USA, [email protected] information about the composition and evolution of metamorphic

fluids, and fluid sources and mass transfer during fluid-rock Leaching of dissolved organic nitrogen (DON) from forest interaction. The fluid composition shows a distinct evolution with (organic–rich) surface soils is likely the primary vehicle for the increasing metamorphic grade, where consecutive zones are observed movement of N into underlying mineral soils. Our goal is to dominated by (1) heavier hydrocarbons, (2) methane, (3) aqueous understand the accumulation and storage of nitrogen in soils. The fluids, and (4) aqueous-carbonic fluids [1]. This study addresses the overarching hypothesis that drives this research is that heterocyclic N chemical evolution of fluids in Alpine fissure veins in the Central compounds derived from the decomposition of litter are transported Swiss Alps by integrating field work, fluid inclusion studies and accumulate in the soil column. The analytical approaches (microthermometry and LA-ICPMS microanalysis of individual typically used to study N-containing compounds are not sensitive to fluid inclusions), and geochemical modeling. the presence of heterocyclic N. This has resulted in the general belief The field locations were selected along a cross section that amide-N (as in proteins/peptides) is the only N form important in through the Central Alps that covers different lithologies and N accumulation and storage in soils. Still, biomolecules such as DNA metamorphic conditions. This includes vein systems in the Aar are composed of heterocyclic N containing subunits and these massif (Gauli glacier, Gerstenegg vein, Tiefen glacier), the Bedretto molecules, although in lower concentrations than amide-N in valley, and the Cavagnoli and Faido region. The fluid inclusions from proteins/peptides, are chemically recalcitrant, sorb onto soil solids, the Aar massif are low-salinity aqueous two-phase, whereas the and are thus expected to accumulate and persist in natural soil Cavagnoli and Faido samples dominantly contain aqueous-carbonic environments. In this investigation, we used an innovative technique, fluid inclusions. The salinity increases from the Gauli samples with nitrogen X-ray absorption near edge structure (N-XANES) 4.5-5.0 wt% equivalent (eqv.) NaCl to those from the Gerstenegg spectroscopy, to determine the N chemical forms in temperate forest and Tiefen glacier with salinities of around 10-11 wt% eqv. NaCl. soils as a function of depth and varying mineralogy. The aqueous-carbonic fluids of the Faido and Cavagnoli region have Soil columns (down to approx. 1 meter) were collected from two very low salinities of around 3.4 and 0.4 wt% NaCl, respectively. forest locations in Pennsylvania. These include an Inceptisol soil with This differences in salinity are also reflected in their major and trace mineralogy dominated by illite and chlorite, and a Spodosol soil with element concentrations, as determined with LA-ICPMS. Higher mineralogy dominated by Fe oxides, illite and kaolinite, but that also salinities do systematically correlate with higher concentrations of contains organic matter accumulations at depths of about 25-50 cm. elements that are largely complexed by chlorine such as the alkali The N K-edge (409.9 eV) XANES spectra was collected at the and earth alkaline metals, and divalent transition metals [2]. The National Synchrotron Light Source, BNL. concentrations of base metals such as Pb, Zn and Ag are consistently The N-XANES spectra of these forest soils can be divided into higher in the fluid inclusions from the Gerstenegg and Tiefen glacier two regions: π* resonances at 398-404 eV and σ* resonances at 404- than in the Gauli samples. The Cavagnoli and Faido samples contain 420 eV. Furthermore, the spectra reveal two well-resolved π* even higher concentrations of ore metals (up to several tens of ppm) resonances, one (lower energy π*) corresponding to spectral features and sulfur, reflecting their higher metamorphic grade. The measured present in biomolecules such as DNA/RNA and their contituent fluid compositions will be compared with results from nucleic acids, and a second resonance (higher energy π*) which is multicomponent-multiphase fluid-mineral equilibria modeling to present in proteins and their contituent amino acids and polypeptides. evaluate the status of fluid-rock equilibrium along the metamorphic We observed an increase in the lower energy π* resonace with soil gradient. depth that was mirrored by a decrease in the higher energy π*

resonace. This trend is consistent for all soil columns, except when an [1] Mullis, J., Dubessy, J., Poty, B., O’Neil, J. (1994) Geochim. Cosmochim. Acta 58, 2239-2267. [2] Yardley, B.W.D. (2005) Econ. accumulation of organic matter occurs in deep soil layers. The lower Geol. 100, 613-632. energy π* resonance originates from molecular structures with extended π-electron systems and indicate the presence of heterocyclic N compunds. Thus, our results indicate N long-term leaching processes result in the selective accumulation of heterocyclic N compounds at soil depths. The accumulation of heterocyclic N at soil depths might be a consequence of its presumed recalcitrance and/or bonding to mineral surfaces.

Mineralogical Magazine | www.minersoc.org 2073 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts

11 Trace element mobility and root iron δ B-based atmospheric CO2 records plaque effects on rice growth in a coal during the Pliocene at orbital mining area of North Vietnam resolution 1* 1 RAUL E. MARTINEZ, J. EDUARDO MARQUEZ*, THI BICH MIGUEL A. MARTÍNEZ-BOTÍ , GAVIN L. FOSTER , 2 2 HOÀNG-HÒA , AND RETO GIERÉ MARCUS P.S. BADGER , RICHARD D. PANCOST , DANIELA N. 3 4 SCHMIDT , DANIEL J. LUNT Universität Freiburg, Geowissenschaften, 79104 Freiburg, Germany [email protected], 1Ocean and Earth Science, National Oceanography Centre [email protected] (* presenting author), Southampton, University of Southampton Waterfront Campus, [email protected], [email protected] European Way, Southampton SO14 3ZH, UK, M.A.Martinez- Botí@noc.soton.ac.uk (*presenting author), [email protected]. The Cam Pha area in Northen Vietnam is known for its coal 2Organic Geochemistry Unit, School of Chemistry, University of mining activities. The Coc Sau open pit coal mine has been operative Bristol, Cantock’s Close, BS9 1TS, U.K., in this area for at least the past 50 years. Rice paddies located ~2 km [email protected], [email protected]. away from the Coc Sau mine are irrigated with water contaminated 3 Department of Earth Sciences, University of Bristol, Wills by acid mine drainage. Bulk chemical analysis of rice paddy soil from the Cam Pha area shows relatively high concentrations of Memorial Building, Queen’s Road, BS8 1RJ, U.K, several toxic metals attributable for the most part to the coal mining [email protected]. activities, including Cr, Cu, Zn, As, Cd, and Pb (60, 27, 48, 14, 0.2, 4School of Geographical Sciences, University of Bristol, University and 35 ppm, respectively). Road, Bristol BS8 1SS, U.K., [email protected]. Preliminary experiments with model Oryza sativa cv. (Asia) rice species exposed to contaminated paddy soil from the Coc Sau mining area showed a hindered growth as a function of increasing The Mid-Pliocene is the most recent time in Earth's history soil concentrations added to rice growth media under controlled when mean global temperatures were substantially warmer and sea laboratory conditions. Figure 1 shows a clearly a detrimental effect of this soil on the growth of model Oryza sativa cv. (Asia) rice levels higher than they are today [1]. The subsequent intensification species. of the Northern Hemisphere Glaciation (iNHG) represents the key In the next step, we will perform sequential extraction analyses final step in the climatic transition from the warm Pliocene to the of the soil to determine the most mobile metals. Moreover, we are current “icehouse” climate. Recent modeling and proxy-based currently studying the effects of root iron plaques and the presence results [2-4] suggest that this climate shift was forced by a reduction iron oxide mineral phases in regards to toxic metal immobilization. in atmospheric CO concentrations (pCO ), which highlights the 2 2 relationship between climate and this important greenhouse gas.

Hence, there is significant potential in the use of the Pliocene as an analogue for future global warming in modeling studies and as a key

period to study the role of CO2 in driving major climatic shifts. Despite recent advances in the reconstruction of pCO2 change during this important period [3-4], detail at the orbital scale is currently lacking. Boron isotopes in planktic foraminifera are a proven proxy for surface oceanic pH [5], which has been shown to provide valuable insights into past changes in the ocean carbonate system and ultimately into past atmospheric pCO2. Here we will provide foraminiferal δ11B-based records to determine the temporal

evolution of pCO2 for an interval spanning the Pliocene Warm Period and the iNGH at orbital scale temporal resolution. Our record provides valuable insights into the causes and consequences Figure 1: Plot of dry rice plant root weight as a function of of the changes in the atmospheric concentration of this important concentration of Vietnamese rice paddy soil (VNS) from Cam Pha greenhouse gas. area. [1] Haywood et al. (2000) Geology 23, 1063-1066. [2] Lunt et al. (2008) Nature 454, 1102-1105. [3] Pagani et al. (2010) Nature Geoscience 3, 27-30, [4] Seki et al. (2012) Earth and Planetary Science Letters 292, 201-211. [5] Sanyal et al. (2001) Paleoceanography 16, 515-519.

Mineralogical Magazine | www.minersoc.org 2074 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Mercury methylation, pore water Computational study of the most geochemistry and legacy mercury stable pyrophyllite edge surfaces for contamination along the floodplain of metal adsorption 1,* 1 the Connecticut River DAVID M. S. MARTINS , MÁRIO A. GONÇALVES , JOSÉ 2 3 1* 2 1 MIRÃO , STEPHEN C. PARKER ANNA MARTINI , JON WOODRUFF , DANIEL KEKACS , 1 1 HANNA BOUBERHAN , AND CARYL ANN BERCERRA 1Department of Geology and CREMINER/LARSyS, Faculty of Sciences of the University of Lisbon, Lisbon, Portugal 1Amherst College, Geology, Amherst, U.S., [email protected] (*[email protected], [email protected]) (* presenting author) 2Department of Geosciences and Center of Geophysics, University 2University of Massachusetts, Geosciences, Amherst, U.S., of Évora, Portugal ([email protected]) [email protected] 3 Department of Chemistry, University of Bath, Bath BA2 7AY, Mercury has long been stored in the fine-grained sediment United Kingdom ([email protected])

along the various tributaries, ponds, lakes, and coves connected to

the Connecticut River. Concentrations rose above background (<80 Abstract ppb) by the dawn of the Industrial Revolution and have, for the most Metal adsorption on mineral surfaces is a topic extensively part, mirrored the rise and fall of atmospheric mercury pursued by researchers to improve the understanding of the concentrations[1]. Total mercury concentrations in the sediment environmental fate of metals, and provide natural low-cost peak upstream in the Oxbow at approximately 500 ppb and near the adsorbents for remediation as this is an active mechanism in mouth of the river, in Hamburg Cove, increase to nearly 3000 ppb. controlling the fate of metal ions in natural waters. Despite the This sixfold rise is further exacerbated by the changing wealth of available information focused mostly with basal surfaces, sedimentation rate from a low at the Oxbow (~1.5 cm/yr) to because edge surfaces are difficult to model, few studies were extremely high values for Hamburg Cove (~4.1 cm/yr)[1]. The rise devoted to edge surfaces of clays.[1-3] in sedimentation rates towards the Long Island Sound are due to the Pyrophyllite was chosen as a model because it is a non influence of tidal pumping, allowing significant quantities of expanding phyllosilicate with neutral layers that do not require sediment fines to accumulate in these depocenters. In comparing encapsulation of couter-ions, making it the best candidate for mass accumulation rates (as μg/m2/yr), Hamburg Cove accumulates calculations that intend to discern such an important and complex mercury at nearly an order of magnitude greater than at the upriver problem. Oxbow. In both locations, organic content ranges from 4 to 14%, The work presented herein follows on from experimental work but does not correlate well with mercury concentrations (R2 = done in our group,[4] and aims at interplaying with such results via 0.2664). Although mercury readily adsorbs onto organic matter, the the investigation of the metal adsorption mechanisms at the edge peaks in mercury concentration are more correlative with surface sites of pyrophyllite. Having been started with a non biased atmospheric loading and local mercury inputs than simply TOC. and systematic approach using atomistic simulation techniques, Methylmercury concentrations are also quite distinct in each initially, the static simulation code METADISE[5] was used to location, with Hamburg containing over 1.5 ppb in its uppermost cleave and hydroxylate low Miller index surfaces, and explore their sediments while Oxbow concentrations never rise above 0.5 ppb. structure and stability. Subsequent to ranking the cuts, classical Variations in MeHg concentrations do not, however, correspond to modeling of the hydrated clay-edge surfaces showed that from the those of total inorganic mercury, but instead suggest that SO4 in large set of Miller index planes cut, the (110), (-110), (010), and pore water and the actions of SRB are needed to methylate the (100) surfaces are the most stable leading to a pseudo-hexagonal stored inorganic mercury. qPCR results also indicate the presence crystal shape generated with the first three surface planes, as of sulfate reducers in these environments, just below the sediment documented for phyllosilicates. These edge surfaces were further interface. For Hamburg Cove this suggests that significant optimised using DFT within the VASP code,[6] to calculate the introduction of the bioavailable form of mercury is controlled by the energy of the diferent hydroxylated ensembles in oder to ascertain occasional influx of salt water (with its high SO4 concentration). the most stable and hence the most likely for metal surface complex With sealevel rise, it is likely that the magnitude of re-introduction formation. of legacy mercury will increase and will eventually effect other

floodplain waterbodies further up the Connecticut River Channel. [1] Bickmore B. R., Rosso K. M., Nagy K. L., Cygan R. T., and Tadanier C. J. (2003) Clays and Clay Miner. 51(4), 359-371. [2] Churakov S.V. (2006) J. Phys. Chem. B 110(9), 4135-4146. [3] Rotenberg, B., Marry, V., Malikova, N. and Turq, P. (2010) J. Phys.: Condens. Matter, 22, 284114. [4] Gonçalves, M. A. and Rodrigues, A. S., Submitted to Chem. Geol. [5] Watson G. W.,

Kelsey E. T., deLeeuw N. H., Harris D. J., and Parker S. C. (1996) J. Chem. Soc., Faraday Trans. 92(3), 433-438. [6] Kresse G. and Furthmuller J. (1996) Phys. Rev. B 54(16), 11169-11186. [1] Varekamp (2003) Environmental Geology Vol ume43, 268-282.

Mineralogical Magazine | www.minersoc.org 2075 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Nitrogen composition of the ancient The volatile element record of Earth's atmosphere from fluid inclusion accretion 1 analysis of Archean quartz B. MARTY

1* 1 1,2 3 B. MARTY , L. ZIMMERMANN , M. PUJOL , R. BURGESS 1CRPG-CNRS, Université de Lorraine, Vandoeuvre les Nancy, 4 AND P. PHILLIPOT France, [email protected]

1 CRPG-CNRS, Université de Lorraine, Vandoeuvre les Nancy, Isotope signatures of volatile elements France, [email protected] The stable isotopes signatures of terrestrial nitrogen and 2ETH, Zürich, Switzerland, [email protected] hydrogen suggest strongly that most volatile elements on Earth 3University if Manchester, UK, [email protected] originated from a cosmochemical reservoir that also sourced 4IPGP, Paris, France, [email protected] asteroidal bodies. However, in the Earth's mantle, a minor solar-like

Introduction volatile component is present and best seen in the Ne (and possibly N and H) isotope composition(s) of mantle-derived rocks. Ne Knowning the composition of the Archean atmosphere is isotopes in minerals from mantle plume provinces discriminate extremely important for a number of reasons. First, the Sun was ~25 against contribution of dust implanted with solar ions, and instead % fainter than Today and, because there is no evidence of glaciation support trapping of volatile elements directly from the nebular gas. in the Archean, rhe lower solar energy delivery was presumably Atmospheric escape to space has been long advocated to account for compensated by a stronger greenhouse effect. Such an effect is not the atmospheric 20Ne/22He isotope ratio lower than the Solar value. I recorded in geological proxies of the paleo partial pressure of CO2, shall argue instead that mixing between solar and chondritic and it has been proposed that doubling the pN2 in the Archean components accounts well for Ne isotope variations in the Earth- atmosphere could have broadened by Rayleigh scattering the atmosphere system. In a 20Ne/22Ne versus 36Ar/ 22Ne diagram, both adsorption line of radiatively active gases, strengthening the the atmosphere and the MORB mantle plot on a mixing line joining greenhouse effect [1]. Because nitrogen isotopes are fractionated by the solar and the chondritic (A-type component) end-members [1]. bacteria, the isotopic siganture of this element in old sedimentary Earth's accretion seen from volatile elements rocks is used to investigate the early development of the biosphere. The above geochemical compositions on one hand, and Thus the isotopic value of the atmosphere at different time periods dynamical modelling of planetary formation [2] on another hand, are is equally important to document. Previous works have proposed that consistent with the following scenario. Planetary embryos of the it remained constant through time within a few permil [2]. Nitrogen and argon isotopes in irradiated Archean size of Mars accreted and differentiated in a few Ma [3], while the quartz nebular gas was still present. Solar-like atmospheres were gravitationnally bound and solar gases were dissolved in molten We have analyzed nitrogen and argon isotopes in 3.5 Ga old silicates, imposing reducing conditions that participated to metal hydrothermal quartz from the North Pole area, Pilbara, NW segregation. Such conditions might have also permitted the trapping Australia. In the same sample we have previoulsy determined a Ar-Ar of minor amounts of solar, isotopically light, N and H. Such plateau age of 3.0±0.2 Ga indicating that the age of trapped fluids is contribution is larger than the late veener advocated in the case of within 3.0-3.5 Ga. The Xe isotope signature intermediate between PGEs. Giant shocks that characterized the accretion of Earth, but not Chondritic and Atmospheric was interpreted as representing of Mars, did not completely dry up the proto-Earth : volatile atmospheric Xe trapped ≥ 3.0 Ga ago [3]. Gases were extracted by elements were gravitationnaly bound as were less volatile, or non vacuum crushing and heating of the remaining powder, nitrogen and volatile, elements also vaporized during the Moon-forming impact. noble gases were purified independently, and nitrogen and argon Delayed accretion of asteroidal bodies or of volatile-rich dust isotopes and abundances were sequentially analyzed by static mass orginating from close to the snowline added chondritic-like volatiles spectrometry (overall G15N error : 1-2 ‰). In a first step we : a contribution of 2±1% carbonaceous chondrite-type material is analyzed non-irradiated samples, and data are consistent with mixing indeed sufficient to supply water, carbon, nitrogen, halogens, and between an hydrothermal end-member and a paleo-atmospheric most noble gases to the Earth (including the surface reservoirs) [1]. component having a G15N value close to the modern one. We then In the light of existing data, the contribution of comets might not irradiated a second batch of samples in order to quantify the have exceeded a few percents of that of asteroidal material. The chlorine and potassium contents of the extraction steps from 37Ar, isotopic fractionation of atmospheric xenon (and, to a lesser extent, 38Ar and 39Ar and to correct data for mixing (and ageing for Ar). The of atmospheric krypton) is probably related to non-thermal escape G15N values are very similar to the ones obtained from the non- processes involving selective ionization, possibly on embryos, or irradiated sample runs, showing neglible production of nitrogen during the Hadean-Archean eons [4] when the young Sun was more isotopes during neutron irradiation. Premiminary results confirm energetic than Today in the far UV range [5]. G15N values between 0 ‰ and 5 ‰, and suggest a partial pressure of

atmospheric nitrogen comparable to the present-day one. [1] Marty, B., (2012) EPSL 313-314, 56-66. [2] Walsh, K.J., et al., (2009) Nature 475, 206-209. [1] Goldblatt, C., et al., (2009) Nature Geosci. 2, 891-896. [3] Dauphas N. & Pourmand, A., (1990) Nature 473, 489-493. [2] Sano, Y. & Pillinger, C.T. (1990) Geochem. J. 24, 315-325. [4] Pujol, M., et al., (2011) EPSL 308, 298-306. [3] Pujol, M., et al. (2011) EPSL 308, 298-306. [5] Ribas, I., et al., (2011) Astrophys. J. 714, 384–395.

Mineralogical Magazine | www.minersoc.org 2076 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Mercury stable isotope time trends in Characterization of combustion cryogenically archived ringed seal products from biomass pellets livers from the Alaskan Arctic 1* 1 CHRISTOPH MASCHOWSKI , RETO GIERÉ , AND GWENAËLLE 2 1* 1 1 2 TROUVÉ J. MASBOU , D.POINT , J.E. SONKE , P.R. BECKER 1 Universität Freiburg, Geowissenschaften, 79104 Freiburg, 1 Observatoire Midi-Pyrénées, Geosciences Environnement Germany, [email protected] (* presenting author), Toulouse, CNRS-IRD-Université de Toulouse 3, France. [email protected] [email protected] (* presenting author) 2 Université de Haute-Alsace, Laboratoire de Gestion des Risques

et Environnement, Mulhouse, France, [email protected] 2 National Institute of Standards and Technology, Hollings Marine

Laboratory, Charleston, South Carolina, USA Two different types of biomass pellets (a DIN+ wood pellet and

a new pellet made of the Miscanthus grass) and their combustion Because of its long residence time in the atmosphere, gaseous products (bottom ash and fly ash) were investigated by Atomic mercury (Hg) emitted from distant anthropogenic sources reaches Absorption Spectroscopy (AAS), Scanning Electron Microscopy high latitude regions carried by air flow [1]. Springtime atmospheric (SEM), Electron Microprobe Analysis (EMPA), and X-ray Hg depletion events (AMDEs) were early on recognized as a diffraction (XRD). Also, an attempt was made to characterize potential key control on Hg entering the Arctic ecosystem. Even if a combustion-derived particles in the exhaust gas by using SEM large amount of AMDE Hg deposited is immediately re-emitted to images and EDX spectra. the atmosphere, the remainder is mobilized by meltwater [2] and The fuels were combusted in a glass tube reactor using a heating transformed by bacteria into methyl-Hg. This neurotoxic form is ramp (20-820°C @ 20°C/min). The particles were collected by an able to bio-accumulate along the trophic chain and high Electrical Low Pressure Impactor (ELPI) on twelve stages concentrations are observed in top predators. Global emission Hg depending on their aerodynamic diameter. The main focus was put trends and AMDEs alone are however unable to explain observed on the alkali, alkaline earth and silicon contents as these compounds temporal trends in biota Hg in Western and Eastern Arctic sectors commonly lead to the formation of corrosive deposits in biomass [4]. Marine mammal’s exposure to MeHg therefore needs additional power plants and may also contribute to hazardous primary and consideration of physiological, ecological and climate change secondary particulate matter in the atmosphere. factors such as feeding behavior, habitat utilization, and sea-ice The results reveal relatively higher potassium and calcium dissappearance. Recent work on arctic seabird eggs [5] has shown a contents in the Miscanthus fuel and its combustion products. On the possible link between sea-ice cover and biota Hg isotope signatures. other hand, the silicon contents of the fuel and the combustion It was inferred that by blocking UV radiation the sea-ice diminishes products are almost identical for the two pellet types. The photochemical breakdown of bioavailable surface ocean MeHg. unexpected high silicon content in the wood pellet is inferred to Here we further explore the potential influence of climate change on result from contamination during harvesting and pellet production, a Arctic Hg biogeochemistry. We focus on ringed seals, a sea-ice hypothesis supported by the presence of extraneous quartz grains dependent species considered as apropriate Hg biomonitors in the observed by SEM. In the Miscanthus pellet potassium and silicon Arctic region. Indeed, their high degree of site fidelity allows were also found inside the cells, and thus represent inherent spatio-temporal analysis of biomarkers. Hg speciation (inorganic inorganic material. In the bottom ash of the Miscanthus pellet, a Hg, MMHg) and stable isotopic composition (C, N, Hg) multitude of mineral phases, predominantly lime, have been measurements were made on 53 ringed seal liver samples archived at identified by XRD, and evidence for ash melting was obtained from the US Marine Environmental Specimen Bank. Sampling covers a SEM observations. In the bottom ash of the DIN+ wood pellet, only period of 14 years (1988-2002), allowing an accurate time trend quartz and calcite were detected, with no indication for ash melting. analysis. The isotopic signature ∆199Hg, which is a tracer for The inorganic particles collected from the flue gas were inorganic or methyl Hg photochemistry in surface waters, varied classified on the basis of their chemical composition and shape in from 0.05 to 1.04 ‰.This variation was not related to in-vivo order to assign them to a probable mineral phase. In the Miscanthus metabolic effects or ecological effects such as feeding habitat particulate matter samples, twelve different inorganic particle types (δ13C) and trophic level (δ15N). ∆199Hg shift from +0.37±0.08‰ with mean diameters from 1-20μm were identified. In the DIN+ (SE, n=5) in 1988 to +0.59±0.07‰ (SE, n=7) in 2002, and show a particulate matter sample, a total of seven different particle types significant increase of 4.8% yearly (R2=0.70, p*<0.05) in this were found, but the main fraction (~80%) is represented by quartz period. We suggest that this reflect the progressive decrease in sea- grains with mean diameters > 10μm. ice cover between 1988 and 2002. This is coherent with our The major part of the inorganic (ash-forming) fraction of the previous study [5]. DIN+ pellet is represented by extraeneous material, whereas

significant amounts of the inorganic constituents of the Miscanthus [1] Macdonald et al. (2005) Sci Total Environ, 342, 5-86 [2] Steffen et al. (2002) Atmos Environ, 36, 2653-2661. pellet are located inside the biostructures. This may lead to higher [3] Loseto et al. (2004) ES&T, 38, 3004-3010. reactivity during combustion and the formation of secondary phases [4] Gaden et al. (2009) ES&T, 43, 3646-3651 such as lime and melilite, and the formation of a wide variety of [5] Point et al. (2011) NGS, 4, 188-194. particle types.

Mineralogical Magazine | www.minersoc.org 2077 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Speciation of commercial CeO2 Towards a new clinopyroxene nanocomposites during aging. geothermometer for alkaline, 1,2* 3 2 1,2 A. MASION , L. SCIFO , P. CHAURAND1, , M.A. DIOT , J. differentiated magmas 1,2 1,2 1,2 1,2 LABILLE , M. AUFFAN , J.Y. BOTTERO AND J. ROSE MATTEO MASOTTA1*, SILVIO MOLLO2, CARMELA FREDA2, 1CEREGE, CNRS-Aix Marseille Univ., France. [email protected] MARIO GAETA1,2 AND GORDON MOORE3 2 iCEINT, Aix en Provence, France 1 3 Sapienza Università di Roma, Rome, Italy TECNALIA, Montpellier, France [email protected] (* presenting author)

2Istituto Nazionale di Geofisica e Vulcanologia, Rome, Italy In many commercial nanoproducts, nanoparticles are 3Department of Chemistry and Biochemistry, Arizona State surface modified to obtain new properties and/or to facilitate their University, USA dispersion in a matrix. Regular use, aging, and improper handling

may cause the release of residues into the environment. As a In the last decades several clinopyroxene geothermometers have consequence, assessing the risks associated with a given been proposed with the aim to constrain pre-eruptive conditions of nanoproduct needs to take into account these residues throughout volcanic systems [1]. However, the compositional bounds of the the entire life cycle of the product. calibration dataset represent a serious limitation in their use. In fact, For example, outdoor wood paint contains CeO2 the more the composition of the investigated natural rocks deviates nanoparticles as long-term UV-absorber to stabilize paints against from the compositions in the calibration dataset, the larger the degradation. The nanoparticles are citrate coated for better uncertainty in the estimate of temperature will be. dispersion in the aqueous paint. This work aimed at investigating the At the present, clinopyroxene geothermometers are mainly transformation occurring at the nanoparticle surface during calibrated on magma compositions ranging from basalt to rhyolite, simulated aging in the lab. leaving poorly constrained or even unconstrained, alkaline Two sets of experiments were conducted: aging of the Ce differentiated composition. Moreover, the effect of melt-water based nanocomposite in aqueous suspensions, and aging of a paint content on phase compositions is usually neglected. Given the containing CeO2 nanocomposites. magnitude of the alkaline, explosive volcanism, these two factors In both cases, the experiments were carried out over several cannot be ignored in future calibrations of geothermometers. months, with UV/Vis illumination to simulate sunlight, and, in the In this study, we present a new clinopyroxene geothermometer case the paint samples, included rain cycles at fixed intervals. During specifically calibrated for hydrous, alkaline compositions ranging the aging, the samples were analyzed in terms of leached Ce content from phonolite to trachyte. This model is based on a broad dataset (paint), and physical-chemical properties (size, charge...) and consisting of 35 phase equilibria experiments, carried out at 200 chemical nature of the residues using mainly microscopy and MPa, in the temperature range 850-1000°C and at variable XH2O-XCO2 spectroscopy techniques. (H2O ranging from 0 to 6 wt.% and CO2 ranging from from 0 to 0.5 wt.%). The equations have been obtained by means of least squares regression analysis of the experimental dataset, yielding a better accuracy of temperature estimate than previous models. Notably, the accuracy of the model largely increases by including the water-melt

content parameter in the equations, whereas the presence of CO2, which actually does not affect the composition of clinopyroxene and melt, scarcely influences the temperature estimate.

[1] Putirka (2008) Rev. Mineral. Geochem. 69, 61-120.

Mineralogical Magazine | www.minersoc.org 2078 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Classification of Groundwater from a Petolorogical diversity of chromian Coastal Granitoidic Fracture Network spinel bearing Matsue Basalt in 1* 2 FRÉDÉRIC MATHURIN , BIRGITTA KALINOWSKI , MATS Shimane Prefecture, Japan. 3 4 ÅSTRÖM AND MARCUS LAAKSOHARJU ICHIRO MATSUMOTO1*, TOMOYUKI TSUBOTA2, ATSUSHI KAMEI3 1Linnaeus University at Kalmar, Sweden, [email protected] AND DAISUKE SATO4 (*presenting author) 1 Department of Education, Shimane University, Matsue, Japan, 2Swedish Nuclear Fuel and Waste Management Co, Sweden [email protected] (* presenting author) [email protected] 2 Saidaiji Junir High School, Okayama, Japan 3Linnaeus University, Sweden, [email protected] 3 Department of Geoscience, Interdisciplinary, Shimane University, 4Nova FoU, Sweden, [email protected] Matsue, Japan

4 Introduction Institute of Geology and Geoinfomation, AIST, Tsukuba, Japan

A groundwater classification system, using the distribution of 18 Matsue Alkaline Basalt the two groundwater conservative parameters Cl and δ O was Matsue city located in Japan Sea coast side of southwest Japan developed at Äspö Hard Rock Laboratory (Äspö HRL). arc. There are many alkaline basic-intermediate lavas that we called Groundwater from boreholes was sampled during the years “Matsue Basalts” in Matsue city area. The activity of the Matsue 1987-2009 from a total of 284 packed-off sections representing Basalt is about 10 Ma ago. Matsue basalt basically consist of 6 basic depths of 8 m to 984 m below the sea level. The groundwater lavas and some it’s pyroclastic deposite (sandstone and tuff) [1, 2]. classification system was based on the conceptual hydrological The purpose of this study is clarifying geochemical characteristics of understanding of the region, including five end-members which, in Matsue basalt. We here report the Bulk rock chemical composition, ascending order with respect to their age, are: deep saline water of and mineral assemblage and chemistry of Matsue Basalt. And we old age [1] but unknown origin (referred to as “old-saline water”), classified Matsue basalt into five groups. And we found chromian glacial melt water formed during the last Pleistocene glaciation, spinels from two groups. This study adds a new data and idea to the Littorina Sea water (mid-Holocene), current meteoric water and Tsubota and Matsumoto (2008) [2]. Baltic Sea water. Results and Conclusions Results and discussion Most of the samples in Fig 1 plot in the Mixed class indicating Bulk rock chemical compositions of Matsue Basalt are divided influences from several end-members. The Meteoric, Marine and into 6 groups, which are 3 basalt groups (Chausuyama, Hanamagari Saline classes are also well represented by the samples. Few and Agenogi groupes), 2 basaltic andesite groups (Tsuda and samples plot close to the Littorina and Glacial end-member Rakuzan groups) and 1 andesite group (Toukodai groupe) based on indicating less influence in the sampled water.” their volcanic Stratigraphy. However, Tsuda and Rakuzan groups are The groundwater classification and results presented here are show same chemical feature. That is Matsue Basalt is chemically relevant for recognition of conditions of importance in terms of consists of 5 groups. Chausuyama and Agenogi basalts show bedrock disposal of toxic waste materials as technical barriers may particularly with respect to their low FeO*/MgO ratios and high Cr be influenced by hydrogeological and hydrochemical changes over content. And these two basalts have chromian spinels in and around time. olivine grains. Chromian spinels from Chausuyama and Agenogi basalts have Cr# (Cr/(Cr+Al) atomic ratio) of 0.16-0.40, and olivines from these basalts have Fo of 88-76. Arai (1987, 1994) proposed that Fo-Cr# relations depend on the tectonic setting, due to differing melting conditions (pressure, temperature and water vapour conditions) [3, 4]. That is Chausuyama and Agenogi basalts of Matsue Basalt derived from the relatively depleted lerzolitic mantle. Furthermore, above two basalts may be the different magma origins by Cr and Ni bulk rock chemical composition. After 5 Ma of activity of Matsue basalt, eruption of adakite magam enters active time at the almost same location as Matsue basalt [5]. That is, it may be able to explain the chemical diversity of Matsu basalt in which it is related also with motion of a Philippine Sea Plate and activity of adakite magma in Japan sea coast side south west Japan arc. Fig. 1. Sampled groundwater plotted according to the established classes: Saline, Glacial, Marine, Meteoric and Mixed. [1] Miyajima et al. (1972) Mem. Fac. Lit. & Sci., shimane Univ., Nat. sci. 5, 131-138. [2] Tsubota & Matsumoto (2008) GCA, Abstract Vol. [1] Laaksoharju et al (2008) Applied Geochemistry 23, 1921-1940. 72, A960. [3] Arai (1987) N. Jb. Miner. Mh. 347-354. [4] Arai (1994) J. Volcanol. Geotherm. Res. 59, 279-294. [5] Sato et al. (2011) Jour. Geol. Soc. Japan. 117, 439-450.

Mineralogical Magazine | www.minersoc.org 2079 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Zn isotope fractionation in Archean Ni partitioning between olivine and komatiites and associated lava-flows high-MgO silicate melts:

N. MATTIELLI1,*, P. HAENECOUR1,2 AND V. DEBAILLE1 Implications for Ni contents of 1Laboratoire G-Time, Université Libre de Bruxelles, Brussels, forsteritic phenocrysts in basalts Belgium (*correspondence : [email protected]) 2Laboratory for Space Sciences, Washington University in St. Louis, A.K. MATZEN, M.B. BAKER, J.R. BECKETT, E.M. STOLPER* St. Louis, USA. California Institute of Technology, Pasadena, CA, USA [email protected] (* presenting author) Komatiites are volcanic ultramafic rocks with high MgO content (>18Wt.%), which make up the first few blocks of the Archean crust There has been considerable interest in the presence in basalts of and are indicative of the earliest stages of the Earth mantle dynamics. forsteritic olivine (ol) phenocrysts with elevated NiO contents (i.e., The present study reports high-precision MC-ICP-MS up to 0.5-0.6 wt. % NiO, substantially higher than in normal perido- measurements of Zn isotopic compositions in whole rocks and titic ol, [typically 0.35-0.40 wt. % NiO]). It is difficult to produce mineral separates from Fred’s Flow and Theo’s Flow, two thick such high NiO contents in peridotitic ol via simple melting processes; Archean differenciated flows (2.7 Ga) located in the Abitibi so assuming that ol phenocrysts that crystallize at low P mimic the greenstone belt (Munro Township, Canada). Fred’s Flow has a compositions of ol in deeper residual magmatic sources, the existence komatiitic affinity, and is classified as Al-undepleted type, whereas of phenocrysts with such elevated NiO contents would require that ol Theo’s Flow has an Fe-rich tholeiitic affinity and is classified as Al- in these sources contain comparably elevated NiO contents. This has depleted type. Their geographical relationship as well as their led to several hypotheses to explain NiO-rich ol in mantle sources of complementary geochemical compositions suggest that they are basalts (e.g., contamination of the lower mantle by the core; metaso- genetically related. Characterizing fractionation processes of their Zn matism of normal mantle by silica-rich melts of eclogite). If, howev- isotope compositions would provide constraints on diffusion er, the partition coefficient of NiO between ol and melt (D ) depends transport, crystallisation processes, and melting conditions involved Ni strongly on T and/or P, ol phenocrysts that crystallize at lower P’s in the komatiites petrogenesis. and T’s than those at which their host magmas last equilibrated with Small but significant shift in δ66Zn values for whole rocks is mantle need not mimic the compositions of ol in their residual systematically observed between Fred’s flow (mean δ66Zn = sources. This would provide an explanation for NiO-rich ol pheno- +0.30±0.04‰ (2SD)) and Theo’s flow profiles (mean δ66Zn = crysts that does not require NiO-enriched mantle ol. +0.39±0.03‰). For each flow, the Zn isotopic profile is relatively We measured D between ol and picritic liquid at 0.001-30 kbar; monotonous, except for the gabbroic units with slightly lower δ66Zn Ni by adjusting the T at each P, we kept liquid MgO contents similar (down to +0.28±0.04‰) and the basal ultrabasic units where (~17-18 wt. %) for all experiments. This experimental feature was enrichments in heavy Zn isotopes are clearly obvious (δ66Zn up to critical because D is a strong function of liquid MgO content; so by +0.55±0.05‰). Ni keeping the MgO content essentially constant, we isolated the de- Zn isotopic compositions in mineral separates vary on a large range pendence of D on P and T from its dependence on MgO. D in our of 1.6 δ-unit, and their relative modal contributions can explain the Ni Ni experiments decreases from 5.0 to 3.8 (by wt.) as T increases from whole rock isotopic trends. As a whole, mineral separates reproduce 1400 to 1550°C. Our results are well described by a simple Ni-Mg the same isotopic shift between the two flows, as previously shown exchange equilibrium assuming (1) ideal models for the liquid and ol by the bulk rocks, suggesting a fractionation control by the and (2) the standard state V and C of the reaction are zero. Pre- crystallisation/melting conditions. Individually, chromites show Δ Δ P vious measurements of D are scattered, but the same model can especially strong enrichments in light Zn isotopes, relative to the Ni describe simultaneously our isochemical results and the literature silicates. Olivine, clinopyroxene and plagioclase exhibit generally smaller isotopic fractionation with respect to each other, but are data in which T and MgO (and P) vary considerably. characterized by contrasted δ66Zn values suggesting correlation with Using our model, we calculated the NiO contents of Hawaiian ol the polymerization degree. No relationship has been observed phenocrysts that would crystallize at 1 kbar from primary magma between the Zn isotope fractionation and (light) alteration degree of separated from its residue at ~35 kbar. If the T difference between the the lava flow or mineral. residue and the conditions of phenocryst crystallization is ~150°C Further analyses are needed to discriminate secondary Zn and the NiO content of residual ol is 0.37±0.02 wt. %, the calculated mobilization, crystallisation or cooling rate effects, and establish NiO content of ol phenocrysts is 0.47±0.025 wt. %. This is not as interesting comparison with Mg and Fe isotopic results reported by high as the highest NiO contents of Fo-rich Hawaiian phenocrysts, Dauphas et al. (2010) on Alexo komatiites. but it matches most of the data (0.44±0.07 wt. % NiO; 2σ). This simple calculation demonstrates that the effect of T on DNi can ex- [1] Dauphas et al. (2010) Geochimica et Cosmochimica Acta 74, plain much of the range in NiO contents of Hawaiian ol phenocrysts 3274-3291. without invoking processes that enrich mantle ol in Ni. Although such Ni-enrichment processes may operate, their contributions to basalt genesis need not be as large as suggested by models that do not consider the effects of T differences between source regions and the environments of phenocryst formation. A similar calculation repro- duces the moderate enrichment in NiO in komatiitic ol assuming komatiitic magmas are dry, deep, and hot melts of the upper mantle.

Mineralogical Magazine | www.minersoc.org 2080 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Geochemical signature and evolution Experimental investigations of the of granitic rocks in Sulawesi Island, structural environment of metal (Nb, Indonesia: evidence for Gondwana Ta) ions in silicate glass-water systems involvement to high P-T conditions 1,4 1 2 1* 2 ADI MAULANA , KOICHIRO WATANABE , AKIRA IMAI , ROBERT A. MAYANOVIC , ALAN J. ANDERSON , MANELICH 1 3 1 2 1 KOTARO YONEZU ,TAKANORI NAKANO LUNA , GIULIO SOLFERINO AND HAO YAN 1Kyushu University, Fukuoka, Japan, 1Missouri State University, Springfield, MO, U.S.A., [email protected] (* presenting author) [email protected] (* presenting author) 2Akita University, Akita, Japan, [email protected] 2St. Francis Xavier University, Antigonish, NS, Canada, 3Research Institute of Human and Nature, Kyoto, [email protected] Japan,[email protected] 4Hasanuddin University, Makassar, Indonesia, adi- The study of silicate and aluminosilicate glasses and water [email protected] systems at high P-T conditions has importance for understanding natural systems and for technological applications. The interrogation of the interaction of water in silicate melts and glasses on the structural level is critical for establishing a better understanding of Tertiary granitic rocks from Sulawesi record series of complex the effect of dissolved water on the thermodynamic and physical history where subduction and collision occur and are still active. properties of water-saturated magmas and of industrial glasses that One of the products of these events is granitic magmatisms which are in contact with high P-T aqueous fluids. In this work, we discuss are widely dispersed from southern part to northern part of the island. The granitic rocks were exposed to form a NS trending belt our in situ Ta L3 and Nb K-edge x-ray absorption spectroscopic along the west to north plutono-volcanic arc province. The granitic (XAS) investigations of the structural environment of metal (Nb, Ta) rocks are of particular interest since they provide an insight into the ions in haplogranitic glasses, water-saturated melts, and silicate-rich geological processes that were operating at the eastern margin of aqueous fluids at high temperatures and pressures. The starting Eurasian Plate. materials, which consisted of water and a Ta (~1400 ppm)- or Nb In this study, major- and trace- element chemistry of granitic (~5000 ppm)-bearing haplogranitic glass of peraluminous pluton from nine areas which represent the whole granitic composition, were loaded into an hydrothermal diamond anvil cell distribution in Sulawesi Island were studied in order to elucidate the geodynamic evolution. In addition, the geochemical signatures and subjected to temperatures between 25 and 960 °C, and pressures coupled with isotopic results are used to determine the up to 600 MPa. Pre-edge peak analysis of the Nb K-edge x-ray corresponding constraint on Gondwana involvement in the evolution absorption near edge structure (XANES) measured from the Nb- of the island. bearing glass+water system to 760 °C shows a transition (in the 300 The results indicate that the granitic rocks ranges from acid to to 400 °C range) from a double to a single peak in the vicinity of the intermediate (granitic to tonalitic in composition) and are dominated glass transition. In addition, the overall intensity of the pre-edge by granodiorite with enclave of microdiorite and gabbro. They are peak feature of the Nb-bearing glass+water system increases identified as medium- to high-K, calc-alkaline, metaluminous and I- type granitoid emplaced as volcanic arc granites. With the exception monotonically with increasing temperature. A doublet occuring in of tonalitic rocks in Gorontalo area in the northern part of the island, the white line feature of the Ta L3-edge XANES is present in the all granitic samples resemble the upper continental crust pattern in spectra measured from the hydrous glass/melt to 700 °C and from their trace and rare earth element normalized pattern. Enrichment of the silicate-rich aqueous fluid at 960 °C. The white line feature large ion lithophile elements (Rb and Sr) and depletion of high field results from dipole allowed transitions of the Ta 2p3/2 core electron strength element (especially Nb and Ta) suggests an arc magma to empty quasi-bound states in the continuum having Ta 5d atomic affinity. Negative Eu anomaly in most of the samples shows the occurrence of plagioclase fractionation in magma chamber. Most of character. The Ta L3-edge XANES spectra measured from a the samples show high 87Sr/86Sr value but low 143Nd/144Nd peraluminous silicate glass and water system have been analyzed suggesting strong upper crustal component source. In addition, they using multi-peak fitting techniques. The normalized XANES spectra have high 206Pb, 207Pb and 208Pb isotope ratios. However, were fit in the vicinity of the white line using pseudo-Voigt peak microdioritic enclave and tonalitic rocks from Gorontalo shows functions. The relative intensities of the individual peaks in the Ta lower 87Sr/86Sr value but higher 143Nd/144Nd and relatively higher L3-edge XANES white-line doublet vary with increasing temperature 206Pb, 207Pb and 208Pb value, significantly different from other of the glass+water system, suggesting a shift in occupation of the samples. The magma sources of these granitic rocks were interpreted electronic density of states in the vicinity of Ta 5d states probed by derived from the upper continental crust. The most plausible nature the 2p3/2 core photoelectron. In situ XANES is shown to be a of such affinity was Gondwana fragment which were dispersed sensitive probe of the modifications in the structural environment during Cenozoic. They were then emplaced above subduction zone surrounding the metal (Nb, Ta) ion in the hydrated peraluminous during the syn- to late collision stages with eastern part of glass/melt and in the silicate enriched aqueous fluid with increasing Sundaland. P-T conditions. We discuss the results of modeling of the XANES The overall geochemical signature of the Sulawesi granitic spectra and calculations of the projected angular momentum density rocks suggests the evidence of Gondwana fragment involvement in geodynamic evolution of the island, particularly in the western and of states (l-DOS) for the glass+water systems using FEFF code. central Sulawesi.

Mineralogical Magazine | www.minersoc.org 2081 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Pb and Hf isotope composition of Sources and Seasonal hornblende-bearing lavas (Central Transformations of Nitrate in Lake European Volcanic Province): a Winnipeg (Manitoba, Canada)

lithospheric mantle source? BERNHARD MAYER1* AND LEONARD I. WASSENAAR2 1* 1 2 BERNHARD MAYER , STEFAN JUNG , ROLF L. ROMER , 1University of Calgary, Calgary, Alberta, Canada, 3 CARSTEN MÜNKER [email protected] (* presenting author) 2Environment Canada, Saskatoon, Saskatchewan, Canada, 1 Universität Hamburg, Mineralogisch-Petrographisches Institut, current e-mail: [email protected] Hamburg, Germany, [email protected] (*

presenting author)

2 Deutsches GeoForschungsZentrum, Potsdam, Germany Lake Winnipeg (Manitoba, Canada) is in an eutrophic state from 3 Universität zu Köln, Institut für Geologie und Mineralogie, Köln, a century of increased riverine loadings from agricultural and urban Germany nitrogen (N) and phosphorus (P) sources. This study investigated

seasonal patterns of the isotopic composition of nitrate (NO -) in Lake 3 Winnipeg and its contributing rivers to gain insight into current N Primitive alkaline mafic volcanic rocks – like the hornblende- nutrient sources and in-lake N dynamics. Elevated NO - bearing basanites from the Rhön area (Central European volcanic 3 concentrations in Lake Winnipeg tributaries between 0.36 and 2.44 Province; CEVP) – provide important information about the mg/L NO --N were associated with high δ15N values between +5.0 chemical composition in the Earth’s mantle. The presence of 3 and +13.9 ‰, while δ18O values were <+15.0 ‰. The three major amphibole requires wet melting conditions; hence the source for the NO3 riverine inputs had distinctive mean δ15N values of +8.1 ‰ for the hornblende-bearing lavas is thought to be located in the lithospheric NO3 Red River, -0.6 ‰ for the Winnipeg River, and +5.0 ‰ for the mantle. Strontium and Nd isotope compositions are well within the Saskatchewan River. The isotopic composition of NO - in Lake range commonly observed in CEVP magmas (HNd: +3.4 to +4.4; 3 Winnipeg was partly controlled by the isotopic composition of the 87Sr/86Sr: 0.7034-0.7041) and, although moderately evolved, are not riverine nitrate for instance via the predominant nitrate input to the indicative of crustal contamination. South basin from the Red River. Nitrate assimilation and late season Beside some differences in major and trace element mineralization of phytoplankton and N fixing cyanobacteria were geochemistry and Sr and Nd isotopes relative to other primitive 2 identified as important additional processes affecting the isotopic volcanic rocks in CEVP, the Pb isotope composition is broadly composition of lake NO - resulting in low δ15N values, especially similar to lavas from other volcanic centers located in the eastern 3 NO3 in the North basin. In the South basin, elevated δ15N values in part of the CEVP (i.e., Vogelsberg, Hessian Depression) in having NO3 spring that changed to lower values by summer indicated a dynamic 206Pb/204Pb ratios < 19.5, which contrasts to the Pb isotope N cycle within the lake. This study demonstrates the need for composition of volcanic centers in the west (Eifel, Siebengebirge, sesoanlly resolved concentration and isotope analyses on samples Westerwald) with 206Pb/204Pb ratios > 19.5. The Rhön lavas have Pb from a large number of sampling sites to assess the highly dynamic isotope compositions (206Pb/204Pb: 19.1-19.4, 207Pb/204Pb: 15.61- in-lake fate of nitrogen inputs to Lake Winnipeg. 15.64, 208Pb/204Pb: 38.9-39.2) that plot slightly above the NHRL

(Northern Hemisphere Reference Line) in the 206Pb/204Pb-

207Pb/204Pb and 206Pb/204Pb-208Pb/204Pb diagram, indicating that the

source of the western CEVP must have a slightly higher U/Pb and

Th/Pb ratio than the source of the eastern CEVP. In general, the Pb

isotope compositions of the lavas plot at the unradiogenic end of Pb isotope range obtained on mantle xenoliths from the CEVP. The hornblende-bearing lavas have initial HHf values ranging from +4.6 to +6.6, which is at least one HHf unit lower than in other lavas from the CEVP having similar HNd values and Pb isotope compostions. Since the Lu/Hf ratios of the hornblende-bearing lavas are similar to other lavas from the CEVP, the Hf isotope composition must be a source feature which is related to distinct Lu/Hf ratios in the mantle. The less radiogenic Hf isotope composition requires a source with a time-integrated lower Lu/Hf ratio relative to the mantle that produced other CEVP lavas with more radiogenic Hf isotope compositions. This inferred lower Lu/Hf ratio is compatible with a mantle with less or even no garnet, i.e. the spinel-bearing lithospheric mantle. Alternatively, participation of metasomatism-related minerals with low Lu/Hf ratios can explain the inferred slightly lower Lu/Hf ratios of the mantle source.

Mineralogical Magazine | www.minersoc.org 2082 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Delivery and release of organic Hydrogen production from low carbon associated with iron temperature (55-100ºC) water-rock oxyhydroxides in the Mississippi reactions 1* 1 2 River-Delta L. MAYHEW , E. ELLISON , T. MCCOLLOM , AND A. 1 TEMPLETON

1 1 1 University of Colorado-Boulder, Geological Sciences LAWRENCE M. MAYER *, LINDA L. SCHICK , MARGARET L. 2 3 1 [email protected] (* presenting author) ESTAPA , ROTA WAGAI , MATTHEW STEVENSON 2 University of Colorado-Boulder, Laboratory for Atmospheric and 1 University of Maine, Walpole ME USA [email protected] (* Space Physics presenting author) 2Woods Hole Oceanographic Institution, Woods Hole MA USA Hydrogen (H2) produced from water-rock reactions at ~150- [email protected] 3 300ºC is known to support thriving microbial communities on Earth National Institute for Agro-Environmental Sciences, Tsukuba, Japan, [email protected] (e.g. Lost City hydrothermal vents [1,2]) and similar geochemical

process have been suggested to occur on Mars and Europa [3,4]. Iron oxyhydroxides commonly associate with organic However, the potential for mafic rocks and minerals to produce matter in terrestrial environments, but can become reductively enough H2 to support microbial life at temperatures below 100ºC dissolved in coastal environments. We examined the organic carbon remains a matter of debate (e.g. [4,5]) and is relatively unexplored in content of these reducible phases using two carbon-free extraction the laboratory. approaches in Mississippi River suspended particulates and in its We are conducting laboratory experiments to assess the adjoining deltaic sediments. Contents of reductively dissolved iron potential of 12 rock and mineral substrates to produce H2 when decreased from river to depocenter and with distance from river reacted with seawater under anoxic conditions at 55 and 100ºC. outfall, and accompanied by similar losses of reductively soluble Time series measurements were obtained for key gaseous and organic carbon. Both also decreased with depth in coastal cores. The aqueous constituents. Magnetite, hypersthene, fayalite, San Carlos ratios of organic carbon to iron released were less than the 0.22 g- olivine and San Carlos peridotite produce 20-180 nmol H2/gram -1 OC g-Fe that represents the approximate sorption limit of iron mineral at 55ºC. The same 5 substrates as well as chromite produce oxyhydroxides for dissolved organic matter, suggesting that the 50-210 nmol H2/gram mineral at 100ºC. In contrast, hortonolite, released organic matter was adsorbed. At these ratios, the solid hedenbergite, augite, enstatite, diopside, and basalt do not produce phase iron and organic carbon are in approximate redox balance, so significant H2. Our H2 measurements agree with previously reported that import of either oxidant or reductant may not be necessary for results from mineral-water reactions at 30, 50, and 70ºC [4,6]. metabolism. The reductively soluble organic carbon generally made However, previous studies did not conduct an analysis of the mineral

up <5% of total organic carbon and its loss thus accounted for small products thus the reactions responsible for H2 gas production are fractions of total organic carbon losses during sediment transport unknown. To address this issue and define the reaction pathways, we and diagenesis. Extrapolation to global scale suggests a greater are using synchrotron-based PXRF and PXANES investigations to impact of perhaps 10% of global river delivery of particulate organic identify Fe-bearing secondary phases and to constrain the

carbon in this form. partitioning of Fe and the mechanisms of H2 generation as a function of mineral composition and temperature. Investigations into the effect of the starting materials (e.g. surface area of the substrates

and substrate and fluid composition) on H2 production are also being undertaken. This work will allow us to constrain the reactions that

produce H2 under low temperature conditions and will provide insight into the potential for water-rock reactions to support microbial life in the deep subsurface and on other planetary bodies.

[1] Kelly (2001) Nature 412, 145-149. [2] Boston (1992) Icarus 95:300-308. [3] McCollom (1999) J. Geophys. Res. 104, 30729- 30742. [4] Stevens & McKinley (2000) Env. Sci. Tech 34, 826-831. [5] Anderson (2001) Env. Sci. Tech 35, 1556-1557. [6] Neubeck (2011) Geochem. Trans. 12:6.

Mineralogical Magazine | www.minersoc.org 2083 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Carbon dioxide degassing and Evidence of paleo sulfate methane estimation of thermal energy release transition zone in marine sediments 1 1* 1 from White Island volcano , New A.PEKETI , A. MAZUMDAR , R. K. JOSHI , H. JOAO, D. J. 2 2 2 Zealand PATIL , L.S. SRINIVAS , A. M DAYAL 1 Gas Hydrate Research Group, Geological Oceanography, National AGNES MAZOT1,SIMON BLOOMBERG2*, TRAVIS HORTON2, Institute of Oceanography, Donapaula, Goa-403004, India CLINTON RISSMANN3, CHRISTOPHER OZE2, DARREN GRAVLEY2 [email protected] (* presenting author) AND BEN KENNEDY2 2National Geophysical Research Institute, Uppal Road, Hyderabad- 1GNS Science, Wairakei, NZ 500606, India [email protected] 2University of Canterbury, Geological Sciences, NZ The sulfate methane transition zone (SMTZ) denotes a redox [email protected]* interface within the anoxic sediment column where pore water 3Environment Southland, Invercargill, NZ sulfate and methane concentration profiles intersect and are depleted to non detectable concentrations. This depletion in sulfate and methane concentrations are attributed to the anaerobic oxidation Accurate quantification and mapping of the total carbon of methane (AOM) performed by a syntrophic consortium of CH4- dioxide (CO ) emitted from a variably permeable volcano still 2 oxidizing archaea and sulfate-reducing bacteria [1]. AOM causes remains a challenge. We used high resolution measurements of CO2 - flux and heat flow within the crater floor of White Island to marked enrichment in H2S and HCO3 ion concentrations in the characterise the mass (CO2 and steam) and heat released. White porewaters within the SMTZ, resulting in precipitation of Fe- Island is an andesite stratocone and New Zealand’s most active sulfides, Ca-Mg-carbonates. Sulfate concentration profile, depth to volcano. Frequent phreatic, phreatomagmatic and magmatic SMTZ and thickness of SMTZ depend on the methane flux. High eruptions have occurred throughout the 19th and 20th century. White Island’s most recent magmatic explosive eruption occurred in 2000. methane flux results in linear sulfate concentration gradient and Currently, the hydrothermal system is manifested by localised shallow SMTZ and vice versa. In the Krishna-Godavari (K-G) basin, vigorous fumarolic activity, mud pools and mounds, and an acidic Bay of Bengal, seismic data [2] show regional presence of gas (pH ≈–0.4) 200 m diameter crater lake, and diffuse degassing through hydrates manifested in the form of a bottom simulating reflector the crater floor. (BSR). Sediment cores for the study were collected on-board

Marion Dufresne and JOIDES Resolution as part of the gas hydrate CO2 flux degassing and thermal budget exploration program in the K-G basin offshoe. Our results show In 2011, we performed 691 measurements of CO2 flux multiple carbonate bearing zones in the sediment with pronounced using the accumulation chamber method. CO2 flux values measured -2 -1 carbon isotopic depletion typical of AOM. Biogenic methane with were ranged between of 0.1 – 29,896 g m d . Total CO2 emission 13 rate estimated by stochastic simulation was 116 ± 2 td-1 within the G C ranging from -80 to -100‰ (VPDB) have earlier been crater floor (0.31 km2). The δ13C range (-10 and -2‰) reflects the reported [3] from K-G basin. In contrast, we have not recorded any spatial variance in magmatic CO2 contribution. Based on CO2 flux appreciable barium front in any of the cores. The barium front data and a mean H2O/CO2 wt ratio of 15.3, the flux of thermal energy possibly diappeared whenever the SMTZ moved up across an released from the crater floor totals 54 ± 1MW. The associated rate of existing Ba front. However carbonate layers are not subject to such steam condensation is 1760 ± 25td-1. The spatial distribution of surface heat flow, soil gas δ13C, surface hydrothermal features and dissolution. The zones with deplted carbon isotope ratios are CO2 flux indicates high gas and thermal permeability at old crater enriched in pyrite with heavy sulfur isotope ratios suggesting 34 margins, and breaks in slope (crater floor/wall, crater floor/mound). Rayleigh fractionation in a closed system. The sharp rise in SCRS We suggest that areas of high degassing are associated with advective indicate focussed sulfate reduction in SMTZ. In the long core gas transport adjacent to persistent fumarole pathways. Areas of low NGHP-01-10D several such zones with heavy sulfur isotope ratios permeability are associated with sulphur/anhydrite and iron oxide- silica precipitation crusts which limit gas diffusion to the surface. In have been noted indicating paleo SMTZ transition zones We propose addition, we explore the influence of sea water and meteoric water that content and stable isotope ratios of authigenic carbonate and influx into the hydrothermal system. pyrite in marine sediments may serves as an ideal tool to detect fossil sulfate methane transition zone in the absence of barium front.

[1] Boetius et al. (2000) Nature, 407, 623– 626. [2] Ramana et al. (2004) International Jour. Enviormental Studies 64, 675-693. [3] Mazumdar et al. (2009) Geophy.Geochem.Geosys., 10, 1-15.

Mineralogical Magazine | www.minersoc.org 2084 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Pore-water chemistry in clays and Investigating marine corrosion shales: Methods and applications communities using tagged 1* 1 MARTIN MAZUREK , H. NIKLAUS WABER AND TAKAHIRO pyrosequencing and single cell 2 OYAMA genomics 1 Institute of Geological Sciences, University of Bern, Switzerland, 1* 1 JOYCE M. MCBETH AND DAVID EMERSON [email protected] (*presenting author), [email protected] 1 2CRIEPI, Abiko-shi, Chiba, Japan, [email protected] Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA [email protected] (* presenting author) A suite of techniques to extract pore waters from clays and [email protected] shales and to analyse them for major ions and isotope ratios have been developed over the last decade. Sophisticated techniques are It was recently discovered that members of the Fe(II)-oxidizing needed to obtain the full pore-water composition, while simple Zetaproteobacteria (Zetas) rapidly colonize mild steel surfaces that crush/leach tests and other laboratory protocols provide information represent a ready source of Fe(II) [1], and that a robust on conservative chemical constituents, such as Cl-, Br-, G18O, G2H microbiologically influenced corrosion (MIC) community develops and dissolved noble gases. Concentration profiles of these on steel that includes Zetas and Epsilonproteobacteria [2]. Here we constituents across shale formations are typically curved, indicating summarize our efforts to expand our understanding of marine steel a transient state of diffusive exchange with the embedding aquifers. MIC bacterial and archaeal communities. We present results from Transport modelling is used to quantify the time scales related to two time series incubations, the first conducted in Great Salt Bay this process, using initial and boundary conditions based on palaeo- salt marsh in summer 2010, and the second conducted below the hydrogeological evidence [1]. This procedure provides insights on marine intertidal zone in Boothbay Harbor, ME in summer 2011. transport processes and on the upscaling of laboratory-derived We used tagged pyrosequencing (V4 region, SSU rRNA gene) to transport parameters to the formation scale. examine bacterial and archaeal communities on mild steel surfaces A comprehensive set of pore-water data has been obtained from from the salt marsh time series (2010). Zetas were identified in drillcores of the Schlattingen borehole, penetrating a Mesozoic, both sediment and steel sample pyrosequencing libraries, and unique clay-mineral rich, low-permeability sequence in NE Switzerland. Zeta OTUs on the steel reflected the numbers observed in the Squeezing tests at 200-500 MPa yielded sufficient water for sedimentary Zeta communities we analyzed. Epsilonproteobacteria chemical and isotopic analysis (Fig. 1), in spite of low water (in particular Sulfurimonas and Arcobacter relatives) were enriched contents (3-5 wt.-%). Salinity decreases with squeezing pressure, on the steel in comparison with sediments. Unique which is an artefact related to the membrane properties of the rocks. Deltaproteobacterial OTUs present increased with incubation time The decline of salinity in the lower part of the profile indicates the to near sediment levels, likely reflecting colonization of the steel by presence of a low-salinity boundary below 1000 m depth, leading to Fe(III)-reducing and sulfate-reducing bacteria (SRB). Archaeal out-diffusion of Cl- from the low-permeability sequence. The time results were dominated by a potentially novel order of scales related to this process are evaluated by transport modelling. Euryarchaeota, most closely related to the Thermoplasmatales. Quantiative PCR of these samples and associated sediments with 16S rRNA gene primers for Zetas and functional gene primers for SRB showed that, on average, Zeta gene copies in sediments were an order of magnitude less abundant than SRB. Zeta gene copies on the steel increased rapidly over the first 10 days, exceeding copies quantified in the sediment by an order of magnitude. The SRB numbers on the steel were 10 fold lower than in sediments during the first days of incubation, but increased to near the sediment levels by 40 days. A 9 day sample from the 2011 time series was subjected to whole genome amplification. Screening of single amplified genomes (SAGs) for bacteria identified 148 bacterial SAGs; 18 (12%) Zetas, 61 (42%) Epsilonproteobacteria (near relatives of Sulfurimonas sp.), and 46 (32%) Gammaproteobacteria (notably 15 relatives of

Hydrogenovibrio sp., an autotrophic H2-oxidizing bacterium). When compared to previous work [2], this study provides evidence for rapid development of a core corrosion community on mild steel. Use of tagged pyrosequencing and single cell genomics enhances our understanding of MIC community richness and provides the possibility of exploring the genomes of individual community - Figure 1: Cl concentrations in pore waters from the Schlattingen members. borehole obtained by squeezing experiments

[1] McBeth et al (2011) Appl Env Microbiol 77, 1405-12. [1] Mazurek et al. (2011) Appl. Geochem. 26, 1035-1064. [2] Dang et al (2011) Env Micro 13, 3059-74.

Mineralogical Magazine | www.minersoc.org 2085 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts The origin and composition of Extreme Fractionation of Rare Earth polyphase inclusions in tourmaline Elements in Volcanogenic Massive from the Greenbushes pegmatite Sulfides of the Bathurst Mining Camp: Evidence from Europium TRAVIS J. MCCARRON1* and ALAN J. ANDERSON2 Anomalies in Hydrothermal Apatite

1 Carleton University, Ottawa, Canada, 1* 2 SEAN MCCLENAGHAN , DAVID LENTZ , AND [email protected] (* presenting author) 3 2St. Francis Xavier University, Antigonish, Canada, PAUL SYLVESTER

[email protected] 1 New Brunswick Geological Surveys Branch, Bathurst,

[email protected] (* presenting author) The (2.527 Ga) Greenbushes rare-element pegmatite in Western 2University of New Brunswick, Department of Earth Sciences, Australia is an important source of lithium and tantalum. The Fredericton, [email protected] pegmatite, which was emplaced syngenetically into the Donnybrook- 3Memorial University of Newfoundland, Department of Earth Bridgetown shear zone within the Western Gneiss terrain of the Sciences, [email protected] Yilgarn Craton, consists of five distinct petrologic zones. Zoned tourmaline crystals in the Ta-rich albite zone of the pegmatite Rare earth element (REE) mobility in hydrothermal systems has been the focus of numerous studies [1,2], with the most direct contain numerous solid-liquid-vapor inclusions. The inclusions evidence coming from active hydrothermal vents [3], which display occur within an inner brown-green pleochroic growth zone and are prominent enrichments in Eu and LREE. Exhalative sedimentary distributed as planar arrays in healed microcracks, oriented rocks generally contain small quantities of REE when compared to subnormal to the c-axis, and as isolated groups. The inclusion- volcanic and clastic sedimentary lithotypes; e.g., massive sulfides of the Bathurst Mining Camp (BMC) have ∑REE contents that average bearing tourmaline is overgrown by an inclusion-free blue-green 36.8 ppm, and range from 0.93 to 249 ppm. Nevertheless, REE in growth zone. Solid phases in the inclusions were identified using massive sulfides of these exhalative horizons can exhibit Raman spectroscopy and one representative polyphase inclusion was considerable fractionation, with chondrite-normalized REE profiles analysed using a dual beam focused ion beam-scanning electron [4] displaying prominent Eu anomalies. Values of EuN/Eu* calculated for massive sulfides are consistently positive with values microscope (FIB-SEM) for three-dimensional textural and chemical as high as 36.7 (ave., 6.26). A positive EuN/Eu* correlation (n=286) characterization. Fluid inclusion assemblages (FIA) show highly with Sn (r'=0.55) and In (r'=0.40) suggests enrichment in primary variable liquid-vapor-solid phase proportions. Measurements of hydrothermal fluids associated with base-metal sulfide precipitation. phase ratios using a petrographic microscope and image analysis Petrography and micro-analytical data for massive sulfides have shown that exhalative gangue and accessory minerals, in particular system show a direct relationship between inclusion size, percent phosphates control REE contents; this is supported by a strong volume solids and mineralogy. Large inclusions (>300Pm2) correlation (bulk) between ∑REE and P2O5 (r'=0.53). Fluorapatite is containing >50% volume solids are dominated by a silicate the most abundant phosphate in exhalites of the BMC, occurring as assemblage, which may contain quartz, pollucite, lepidolite, nodular to colloform masses and intimate mixtures with carbonate and sulfide minerals. Imaging of fluorapatite reveals a distinct zabuyelite and an arsenic-antimony rich phase (predominantly native cathodoluminescence consistent with the substitution of Mn2+ and arsenic, senarmontite, paakonenite and/or arsenolite) and aqueous Eu2+ in the fluorapatite mineral structure and suggests formation carbonic fluid. Intermediate sized inclusions ranging from 5-50% under reducing hydrothermal conditions. volume solids may contain zabuyelite, an arsenic- bearing phase and In situ laser-ablation ICP–MS analyses (n=169) reveal elevated 2 ¦REE contents in fluorapatite, averaging 1,548 ppm, and ranging aqueous carbonic fluid. The smallest inclusions (<100Pm ) have from 250 to 24,038 ppm. Europium accounts for approximately ¼ less than 5% volume solids and contain aqueous carbonic fluid and of all REE substitution in apatite, with Eu contents as high as 1,554 an arsenic-bearing solid phase. Rare nahcolite and lithiophosphate ppm (ave., 295 ppm). Chondrite-normalized REE profiles display were also identified in some inclusions. The variability in inclusion prominent enrichment in Eu, with EuN/Eu* values as high as 222 (ave., 19.0). To date, these anomalies represent the largest reported size and phase proportions within a FIA is attributed to mineral fractionation of Eu in the solar system, exceeding values for precipitation prior to trapping and inclusion necking. The inclusions mesosiderites, and both terrestrial and lunar anorthosites [5]. This are interpreted to represent the products of a silicate-rich aqueous extreme fractionation of Eu suggests protracted growth of apatite or carbonic fluid that was entrapped during the growth and some precursor phase (i.e., francolite) under reducing (low fO2) and high temperature hydrothermal (>250ºC) conditions, further recrystallization of the early brown-green tourmaline. corroborated by the prevailing pyrrhotite-pyrite-chalcopyrite stockwork assemblage. Apatite associated with lower temperature assemblages exhibits diminished Eu signatures, reflecting a more- distal hydrothermal environment and defining a vector for mineralization.

[1] Graf (1977) Econ Geol 72, 527-548. [2] Campbell et al. (1984) Chem Geol 72, 181-202. [3] Michard (1989) Geochim Cosmochim Acta 53, 745-750. [4] McDonough and Sun (1995) Chem Geol 120, 223-253. [5] Mittlefehldt et al. (1992) Science 257, 1096-1099.

Mineralogical Magazine | www.minersoc.org 2086 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Serpentinization and the flux of Investigating biomineralized reduced volatiles to the seafloor structures and morphology 1* 2 THOMAS M. MCCOLLOM , FRIEDER KLEIN , WOLFGANG associated with laminated freshwater 3 4 5 BACH , BRUCE MOSKOWITZ , THELMA BERQUÓ , AND stream terraces: Stromatolites? 1 ALEXIS TEMPLETON C. MCCORT1*, E. CHI FRU2, S. GOUDEY3, AND C.G 1University of Colorado, Boulder, CO, USA, WEISENER1 [email protected] (* presenting author) 2Woods Hole Oceanographic Institution, Woods Hole, MA, USA 1Great lakes Institute for Environmental Research, University of 3University of Bremen, Bremen, Germany Windsor, Windsor, Canada, [email protected]; 4Institute for Rock Magnetism, University of Minnesota, [email protected] Minneapolis, MN, USA 2 Department of Paleozoology, Swedish Museum of Natural History, 5Concordia College, Moorhead, MN, USA Stockholm, Sweden, [email protected] 3Limnos Ltd., Calgary, Canada, [email protected] Serpentinization of ultramafic rocks has long been recognized Introduction to be a source of reduced volatile compounds, particularly hydrogen Biogeochemical cycles are considered the driving force behind (H2) and methane (CH4). Over the last couple of decades, there has how elements are transported and buried in sediments. A principle been increasing scientific interest in the capacity of these reduced mechanism in the addition and removal of elements in compounds to support chemolithoautotrophic biological biogeochemical cycles involves biomineralization. In the strict communities, both now and on the early Earth. In the deep sea, context we can classify biomineralization as extracellular, serpentinization of ultramafic rocks can serve as a source of H and intracellular or as catalytically induced depending on the organisms 2 in question. Investigation of the Erickson Creek watershed BC CH4 to biological communities living within the ocean crust, at the Canada, has led to the discovery of interesting phenomena involving seafloor where fluids are discharged from serpentinites, and in the cementation of the streambeds possibly affecting aquatic habitats overlying water column. The abundance and spatial distribution of adjacent to coal mine impacted riparian zones. serpentinite-supported autotrophic communities depends on when, These mineralized mats are calcareous in nature and have where, and how much reduced volatiles are generated. managed to form densely layered sequences associated with proliferation of freshwater mosses/biofilms. The streams support The production of reduced volatiles during serpentinization localized assemblages charaterized by benthic, alkaliphilous diatoms depends strongly on the fate of Fe as the reaction proceeds, since with relatively low species richness. To investigate the process the generation of reduced compounds is directly linked to the attributing to the biomineralized event, samples were collected to oxidation of Fe(II) to Fe(III). Serpentinization is often portrayed as determine the casual relationships been the mosses, bacteria and the a fairly straightforward process whereby ultramafic rocks are in situ mineralization that is taking place (Figure 1). SEM and Raman microscopy provide structural, morphological, and chemical converted to a limited set of minerals dominated by serpentine information about the biomineralized structure within aged layers. In polymorphs, brucite, and magnetite. Within this rather simple addition, DNA extraction, species richness and identification, was framework, however, there is a lot of room for complexity. In used to determine biological composition. particular, it is increasingly clear from petrologic studies, laboratory experiments, and numerical modeling that the distribution of Fe among reaction product minerals, and the oxidation state of Fe in those products, is highly variable, and is dependent on a complex mixture of factors including temperature, kinetics of dissolution, precipitation and diffusion, bulk rock and mineral compositions, extent of reaction, and thermodynamic constraints. A recent bevy of laboratory experiments by both ourselves and others [e.g., 1-3] focusing on the fate of Fe during serpentinization is providing new

insights into pathways leading to generation of H2 and other reduced compounds, and will provide the basis for improved models of the Figure 1: (A) laminated structure of biomineralized mat, (B) top flux of reduced volatiles from serpentinization environments within down surface showing freshwater moss, (C) SEM micrograph the ocean crust. We will present results from a series of suggesting the existence of localized chemically reduced experiments that examine production of H2 and concurrent mineral microhabitats with S/Fe precipitation. alteration during serpentinization of olivine and peridotite at temperatures from 230 to 320 ºC. Conclusion This data will provide insight and address questions pertaining to [1] Seyfried et al. (2007) Geochim. Cosmochim. Acta 71, 3872- the cementation process at this location and its affects on aquatic 3886. [2] Marcaillou et al. (2011) Earth Planet. Sci. Lett. 303, 281- habitats influenceing the biogeochemistry and microorganisms that 290. [3] Malvoisin et al. (2012) J. Geophys. Res. 117, live in this environmental system. doi:10.1029/2011JB008612.

Mineralogical Magazine | www.minersoc.org 2087 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Microbially-accelerated carbon Compositional models of the Earth sequestration and early planetary evolution 1* 2 JENINE MCCUTCHEON , IAN M. POWER , ANNA L. WILLIAM F. MCDONOUGH 2 2 1 HARRISON , GREGORY M. DIPPLE AND GORDON SOUTHAM Geology, Univ Maryland, College Park, USA [email protected] 1Department of Earth Sciences, The University of Western Ontario, London, ON CANADA, [email protected] (*presenting author) New chemical data along with a broad range of other chemical, 2Department of Earth and Ocean Sciences, The University of British isotopic and physica data that have come to light over the last decade Columbia, Vancouver, BC CANADA will be integrated into a coherent planetary model. Present day compositional models for the planet are non-unique and strongly This investigation modelled microbially-accelerated carbon influenced by the method used in its construct: cosmochemical, sequestration through the precipitation of carbonate minerals. A geochemical/petrological, and geophysical. Cosmochemical models microbial consortium, collected from a natural hydromagnesite examine candidate accretion materials (i.e., chondrites) from which playa near Atlin, British Columbia, Canada, was used to inoculate a the Earth was built and compares these compositional input against 10 m long flow-through bioreactor. The consortium contained physical data that describes the planet to minimize the misfit. cyanobacteria, which are able to mediate magnesium carbonate Geochemical models deconvolve compositional data from samples of precipitation by changing the water chemistry, particularly by the mantle and crust to estimate the concentration of elements in the increasing pH. A bicarbonate-rich nutrient solution containing 1 g/L primitive mantle and then compares these input against chondrite data Mg was added to the bioreactor at a rate of 5 L/day for 7 weeks. to describe the core composition with a minimum misfit. Geophysical Major ion concentrations, pH, dissolved oxygen, and conductivity models use the present day boundary condition for the Earth to find were monitored weekly along the length of the bioreactor. The consistent solutions to the thermal evolution of the planet and the concentration of Mg2+ and other major cations was determined using mineralogy of the mantle. inductively coupled plasma atomic emission spectroscopy, while ion Recently reported geoneutrino data are consistent with most chromatography was used for major anions. An alkalinity titration existing Earth models, and now exclude, at the 67% confidence level, was used to quantify the bicarbonate concentration. The precipitation models that invoke a homogeneous, fully radiogenic Earth model. of carbonate minerals was inferred by the measured decrease in Stable (O, Ca, Ti, Cr, Ni, Mo) and radiogenic (142Nd, Sr, Hf) isotope [Mg2+] and alkalinity along the length of the bioreactor. Carbonate data for chondrites provide a perspective and perhaps a constraint on precipitation occurred, primarily as dypingite, which was confirmed which group of chondrites best fit the bulk Earth composition. using light microscopy, scanning electron microscopy, and x-ray Increasingly, these data find the greatest misfit between the diffraction. The first 3 m of the bioreactor, dubbed the active zone, composition of the Earth and that of carbonaeous chondrites, whereas was responsible for removing over 37% of the Mg added to the better fits are observed for the Earth and enstatite and ordinary bioreactor from solution, versus 61% Mg removed from the entire chondrites. Models that describe the planetary proportion of Fe, O, system. A mass of 0.362 kg of Mg carbonate precipitated in the Si, Mg (>90% of the Earth’s mass) define the mass of core and active zone via microbially-mediated mineralization. This amount of mineralogy of the mantle, with the latter potential describing a mineral precipitation over the course of the experiment translates to compositionally layered state. No chondritic material, present in our 2 a carbon sequestration rate of 5.88 kg of CO2/m of microbial collections, are consistent with data for the Earth and demonstrate mat/year. that adhoc adjustments are needed to describe the nature of the This investigation demonstrated the process of microbe-induced building blocks of the Earth. Matching compositional models of the carbonate precipitation on a larger scale than previous studies [1,2]. primitive mantle with that for the continental crust constrains the This biogeochemical process may have industrial applications if it family of permissible compositional and mineralogical models for the can be implemented on the scale of mine tailing storage facilities present day mantle and any potential stratification. Data and such as those at the Mount Keith Nickel Mine in Western Australia. uncertainties will be presented for quantitative models that describe Magnesium weathered from ultramafic waste rock would react with the concentration and distribution of elements, particularly the heat

CO2 in the presence of the microbes and aqueous chemistry producing elements, in the present day mantle. Models invoking conditions studied in this investigation. The Mount Keith Mine deep mantle reservoirs (BMOL, 142Nd-layer, primitive mantle produces tailings at a rate of 11 Mt/year, with tailings covering an regions, upper/lower boundaries) will be assessed quantitatively. All area of ~19 km2 [2,3]. Application of the biogeochemical process model predictions from the three approaches described above are studied in this investigation to the Mount Keith Mine could result in presently permissible given uncertainties, however ever accumulating

a CO2 sequestration rate of over 111 700 t/year. Globally, there are geoneutrino data sets will provide tighter bounds by which one can many mine sites with microbially-accelerated carbon sequestration critically assess the viability of Earth model compositions. potential, making the results of this study relevant to the current efforts to reduce net greenhouse gas emissions.

[1] Power et al. (2007) Geochem. Trans. 8:13 [2] Power et al. (2011) Env. Sci. and Technol. 45, 9061-9068. [3] Grguric (2003) Aust. J. Mineral. 9, 55-71.

Mineralogical Magazine | www.minersoc.org 2088 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Episodic, post-supereruption Lacustrine cave carbonates: novel, resurrection of the Peach Spring absolute-dated paleohydrologic magmatic system (western Arizona, archives in the Bonneville Basin USA) over ~2 Ma (Utah, USA) 1* 1 1,* 2 3 SUSANNE M. MCDOWELL , CALVIN F. MILLER , CHARLES A. DAVID MCGEE , JAY QUADE , R. LAWRENCE EDWARDS , 2 3 4 3,5 FERGUSON , AND JOE WOODEN WALLACE S. BROECKER , HAI CHENG , AND ELENA 1 STEPONAITIS 1Vanderbilt University, Earth & Environmental Sciences, [email protected] (* presenting author) 1Massachusetts Institute of Technology, Cambridge, USA, 2Arizona Geological Survey, [email protected] [email protected] (* presenting author), [email protected] 3Stanford University, [email protected] 2Univ. of Arizona, Tucson, USA, [email protected] 3Univ. of Minnesota, Minneapolis, USA, [email protected] The Silver Creek caldera (southern Black Mountains, western 4Columbia Univ., New York, USA, [email protected] Arizona) is the source of the 18.8 Ma supereruption that produced 5Xi'an Jiaotong Univ., Xian, China, [email protected] 3 the Peach Spring Tuff (PST), a t700 km ignimbrite that crops out in northwestern Arizona, southern Nevada, and southeastern California Records of past changes in closed basin lake levels and lake 2 [1, 2, 3]. Intruding the caldera’s eastern margin is a ~30 km water isotopic composition provide key insights into past variations epizonal, intermediate to felsic plutonic complex. The complex in the hydrological cycle; however, these records are often limited reveals a ~2 Ma history of episodic, post-PST magmatic recharge, by dating precision and temporal resolution. Here we present data suggesting that this magmatic system was periodically revitalized from lacustrine cave carbonates, a novel class of carbonates that long after its colossal eruption. comprise a promising new archive of past hydrologic changes in the Indications of magmatic rejuvenation are evident throughout the Bonneville Basin of the northeastern Great Basin (U.S.A.). These intrusive complex, which consists of two primary, texturally-diverse dense carbonates precipitated within caves, crevices and other units: the coarse-grained Moss porphyry (~62-68 wt. % SiO2) in the protected spaces flooded by Lake Bonneville during its highstand in north, and the fine- to coarse-grained, commonly granophyric Times the last glacial period. We focus on deposits in Cathedral and porphyry (>70 wt. % SiO2) in the south. The Moss displays locally Craners caves, located ~50 km apart at a similar elevations abundant, 2-10 cm rounded enclaves (59 wt. % SiO2). Near the approximately 100 m above the modern Great Salt Lake and almost Moss/Times contact along Silver Creek, a crystal-rich Times matrix 200 m below Lake Bonneville’s highstand shoreline. Carbonates consisting of rounded feldspars set in a fine-grained groundmass from the two caves show similar chronologies, mineralogical hosts 0.5-2 m enclaves with intermediate compositions. Rapakivi transitions, isotopic compositions and trace element concentrations. feldspars appear in both units, and mafic, intermediate, and felsic These findings suggest that lacustrine cave carbonates record porphyry dikes crosscut the entire complex. changes in lake level and in the isotopic composition and chemistry U-Pb SHRIMP zircon ages and mineral geochemistry support of lake water. Importantly, the deposits can be precisely dated by U- field evidence for magmatic recharge. The Times, the Moss, and a Th methods, providing the first high-precision, absolute-dated distinctive porphyry similar to the Moss yield zircon age spectra of records of Lake Bonneville’s water balance changes. ~16.8-19 Ma (coeval with nearby volcanics), though PST-age We use dates for the onset and cessation of lacustrine cave zircons are notably scarce. Probability density analysis indicates two carbonate deposition to offer new constraints on past changes in main age peaks at ~17.4 and ~18.2 Ma, with the Moss containing a lake level and the carbonate saturation state of lake water. We also larger population of older grains than the Times. Moss zircon and present precisely dated, high-resolution oxygen and uranium isotope sphene record increasing concentrations of Ti and Zr, respectively, records from the deposits. Within a first phase of deposition from core to rim, consistent with reheating. reflecting the lake’s transgression between 26 and 18 ka, our A preliminary interpretation of the data is that the Moss was isotopic data suggest a large influx of freshwater during Heinrich emplaced in the shallow crust at ~18 Ma and substantially reheated Stadial 2. A hiatus in deposition beginning 18.2 ± 0.3 ka may be the and reactivated at ~17.4 Ma, roughly coincident with emplacement result of freshening related to the lake’s overflow. Calcite of the Times. The wide zircon age spread may reflect other deposition resumes at Cathedral Cave at 16.4 ± 0.2 ka, suggesting recharging events that are irresolvable via SHRIMP dating. that basin overflow had ceased by this time and that the lake re- Regardless, the shallow subvolcanic system appears to have been entered calcite saturation; this interpretation implies that the lake’s sporadically resurrected over one to two million years following the deglacial regression began well before the Bølling warming. PST supereruption. Cessation of this second phase of deposition at 14.7 ± 0.2 ka may reflect the lake’s drop below Cathedral Cave’s elevation. [1] Ferguson et al. (in review) Geology. [2] Buesch et al. (1992) We have located similar deposits at over forty locations in the GSA Bulletin 104, 1193-1207. [3] Glazner et al. (1986) Geology basin spanning almost the entire ~270 m elevation range between the 14, 840-843. modern Great Salt Lake and the highstand shoreline. We present data from several elevations that offer additional constraints on changes in lake level and lake chemistry during the last glacial period and deglaciation.

Mineralogical Magazine | www.minersoc.org 2089 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Life at the fringe: redox conditions Geologic Storage Mavericks: Insights around a 1.6 Ga submarine vent and Promise from Laboratory and

PETER MCGOLDRICK1*, JOSHUA GUILLIAMSE2, TOBY Field Pilot Studies in Flood Basalts 3 4 DAWBORN , AND DONNA SATTERTHWAIT B. PETER MCGRAIL 1 CODES ARC Centre of Excellence in Ore Depoits, University of Pacific Northwest National Laboratory, Richland, Washington, USA, Tasmania, Hobart, Australia, [email protected] [email protected] (*presenting author) 2 Geological Survey of Western Australia, Perth, Australia, Abstract [email protected] “Maverick” according to the Merriam-Webster dictionary is 3 Teal Exploration & Mining, Chingola, Zambia, [email protected] defined as “One that refuses to abide by the dictates of or resists 4 School of Earth Sciences, University of Tasmania, adherence to a group.” Hence, “maverick” is apropos for anyone [email protected] seriously studying flood basalts for sequestration of carbon dioxide.

Continental flood basalts represent one of the largest geologic The supergiant Century sediment-hosted Zn-Pb-Ag deposit structures on earth but have received comparatively little attention for formed in an outer shelf setting [1] from a submarine hydrothermal geologic storage of CO2. In fact, flood basalts have flow tops that are vent system developed on, or very near, the seafloor[2]. The mine porous, permeable, and have enormous capacity for storage of CO2 or sequence comprises variably sulfidic (mainly sphalerite) and sideritic other gases of interest. In appropriate geologic settings, interbedded siltstones and carbonaceous shales [1,3]. It is somewhat (~1.5x) sediment layers and dense low-permeability basalt rock flow interior thicker than equivalent strata observed in a drill-core (MMG788) sections may act as effective containment for injected gases. For CO2 5km to the west, suggesting sub-basin development at the site of ore sequestration purposes, containment is critical so that sufficient deposition [3]. Unlike other northern Australia Proterozoic sedex Zn residence time is established for mineralization reactions to occur. deposits, Century is relatively low in pyrite. Initial laboratory experiments conducted nearly a decade ago with Sideritic siltstones in the mine sequence are characterised by scCO2 showed rapid chemical reaction of CO2-saturated pore water crinkly and whispy carbonaceous, bedding-parallel seams, previously with basalts to form stable carbonate minerals. However, recent interpreted as stylolites. We have re-interpretted these features as discoveries in laboratory tests with water-saturated supercritical CO2 microbialites. Their diversity and abundance in the mine sequence, show that mineralization reactions occur directly in this phase as compared to drill-core MMG788, is consistent with locally abundant well, providing a second and potentially more important biological activity at the site of ore formation. mineralization pathway than was previously understood. In fact, in Major element geochemical data and iron speciation deep geologic settings, mineralization by water-wet scCO2 is the measurements from samples from the mine and MMG788 indicate dominant mineralization pathway. But, despite many years of anoxic (ferruginous, not sulfidic) conditions mostly prevailed [3]. laboratory investigation, the remarkable 10 fold variability in This is despite several hundred million tons of biogenically reduced S reactivity of different basalts remains an unresolved scientific having been sequestered into the Century deposit. question, defying easy correlation to mineral makeup or chemical We will present new Mo, P and organic C data from the mine compositional differences in the basalts. sequence that speak to locally high primary organic productivity. In this paper, we will also discuss an important leveraging Organic matter thus produced may have been fuel for biogenic sulfate application of the work on CO2 sequestration in basalts for reduction sufficient to form the Century Zn sulfide orebody. compressed air energy storage to help manage electric grid stability

in the Pacific Northwest. Here, mineralization reactions need to be [1] Andrews et al. (1998) Economic Geology 93, 1132-1152. avoided to prevent reservoir permeability decline over the course of [2] Feltrin et al. (2009) Computers & Geoscence 35, 108-133. many air injection and extraction cycles. Oxygen depletion through [3] Guilliamse (2010) Unpub. BSc(Hons) thesis, University of reaction with Fe(II) in the basalts also might need mitigation if the Tasmania 86pp. extracted air is to be used directly in a combustion turbine.

Field testing of CO2 storage in basalts is proceeding with drilling

of the world’s first supercritical CO2 injection well in flood basalt being completed in May 2009 near the township of Wallula in

Washington State and corresponding CO2 injection permit granted by the State of Washington in March 2011. Injection is in the final planning stage. In Iceland, the CARBFIX project has drilled an injection well and several monitoring wells and plans to test injection

of groundwater saturated with a CO2-H2S gas mixture obtained from a geothermal power plant. If proven viable by these field tests and others that are in progress or being planned, major flood basalts in the

U.S., India, and perhaps Australia would provide additional CO2 storage capacity and regional sequestration options in these countries where conventional storage is limited, and also provide tangible benefits for future applications in energy transmission and storage.

Mineralogical Magazine | www.minersoc.org 2090 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts The role of surface charge and A Tertiary record of Australian plate exchange cation speciation on the motion from ages of diamondiferous structure of interfacial water in alkalic intrusions nontronite suspensions 1* 1,2 BRENT MCINNES , NOREEN EVANS , 1 1 1 1,2 JUSTIN V.T. ROTH, CHRISTOPHER A. HEIST, AND MOLLY M. FRED JOURDAN , BRAD MCDONALD , 1* 3 1 1 MCGUIRE JOHN GORTER , CELIA MAYERS AND SIMON WILDE 1Bucknell University, Department of Chemistry, Lewisburg, PA, U.S.A., [email protected] (* presenting author) 1 John De Laeter Centre for Isotope Research, Curtin University, Perth Australia, [email protected] (* presenting author), Attenuated total reflection infrared spectroscopy (ATR-FTIR) [email protected], [email protected], was used to investigate the structure of water at the surface of [email protected] suspensions of the nontronites, NAu-1 and NAu-2. Raw ATR spectra 2 CSIRO Earth Science and Resource Engineering, Perth, Australia, were converted to absorption index (k) spectra via the Kramers- [email protected], [email protected] Kronig transform to allow direct comparison of samples with 3 Eni Australia Ltd, Perth, Australia, [email protected] different indices of refraction. Difference spectra produced from these k spectra allowed subtle shifts in the O-H stretching region to Multiple geo/thermochronometry datasets (zircon (U-Th)/He1, be discerned, thereby providing information about differences in the phlogopite 40Ar/ 39Ar and wadeite 40Ar/ 39Ar) have been acquired from degree of hydrogen bonding. Suspensions of both NAu-1 and NAu-2 four Western Australian kimberlite and lamproite localities exchanged with either Na+ or K+ exhibit increased hydrogen- distributed over 850 km. The linear orientation of the eruption bonding at the mineral/water interface as compared to bulk water. centres (~015°), southwardly younging emplacement ages, and NAu-1, which has greater total and tetrahedral charge than NAu-2, apparent co-linearity with modern geodetic measurements has shows no change in water structure upon reduction of structural Fe or implications for Australian plate geodynamics (Fig. 1). the addition of a small excess of electrolyte. These observations The Fohn diatreme field consists of ~30 lamproite pipes suggest that the ordering of interfacial water in NAu-1 suspensions is discovered during oil exploration in the Timor Sea2. Phlogopite dominated by the highly charged mineral surface. Reduction of recovered from lamproite cuttings in an offshore exploration well structural Fe in NAu-2 results in changes to the interfacial water (Fohn-1) returned a robust plateau 40Ar/ 39Ar age of 29.4 ± 0.7 Ma structure that are dependent on the exchange cation species. In this (P=0.99). A diamond pipe from the North Kimberley kimberlite case, reduction produces a significant increase in tetrahedral charge, field (Seppelt) yielded four zircon grains with thermally reset (U- which alters the interactions of the exchange cations with the surface. Th)/He ages averaging 25 Ma. Diamondiferous pipes at Ellendale contain xenocrystic zircon grains with (U-Th)/He ages of 20.6 ± 2.8 Ma that were thermally reset by lamproitic intrusions. Other researchers3 report K-Ar ages for the Noonkanbah lamproite field of ~19 Ma, whereas 40Ar/ 39Ar dating of wadeite from the Walgidee Hills lamproite yielded plateau ages of 17.46 ± 0.17 Ma (P=0.44).

Figure 1: Age-distance relationships of WA lamproites (red) and Australian plate motion as determined by GPS (blue arrow). Geodetic measurements indicate that the Australian plate is currently moving NNE at a rate of 60-75 mm/year relative to the Eurasian plate, whereas long period geospeedometry estimates range from 50-78 mm/year4. The age-distance relationship between the Fohn and Wolgidee Hills sites in this study are consistent with a plate motion of 70 mm/yr during the Tertiary.

[1] McInnes et al (2009) Lithos 112S, 592-599. [2] Gorter and Glikson (2002) AJES 49, 847-868. [3] Jaques et al (1986) GSWA Bull. 132, pp. 267. [4] Wellman and McDougall (1974) Tectonophys. 23 49–65.

Mineralogical Magazine | www.minersoc.org 2091 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Effects of polydispersity on natural Origin, distribution and organic matter fate and transport hydrogeochemical controls on

DANIEL MCINNIS, LINDSAY SEDERS DIETRICH, DIOGO methane occurences in shallow BOLSTER, AND PATRICIA MAURICE* aquifers in southwestern Ontario University of Notre Dame, Civil Engineering & Geological Sciences, 1* 2 JENNIFER MCINTOSH , STEPHEN OSBORN , STEPHEN 156 Fitzpatrick Hall, Notre Dame, IN 46556, USA 3 4 GRASBY , AND STEWART HAMILTON [email protected], [email protected], [email protected], 1 [email protected] (* presenting author) Department of Hydrology and Water Resources, University of Arizona, Tuscon, AZ 85721, USA, [email protected] Natural Organic Matter (NOM) is a polydisperse material whose 2Geological Sciences Department, California State Polytechnic components display a range of adsorption rates and affinities as University Pomona, Pomona, CA 91768, determined largely by molecular weight (MW). In this study, the [email protected] mobility of NOM was examined in sand columns at pH 5-8, in 0.001 3Geological Survey of Canada, Calgary, Alberta, AB T2L 2A7 to 0.1 M NaClO4. Effluent data were modelled using the advection-

dispersion equation (ADE). Greater overall mobility of NOM was [email protected] observed at higher pH and lower ionic strength. High-pressure size 4Ontario Geological Survey, Sudbury, Ontario P3E 6B5, exclusion chromatography (HPSEC) was used to monitor the MW [email protected] distribution of column effluent; results were consistent with fractionation by preferential adsorption of intermediate to high MW components, as previously observed in many batch systems. Abstract Transport rates of different components were quantified by dividing Fractured organic-rich shales, such as the Marcellus, Antrim, the MW distribution into separate ‘bins’ and examining breakthrough and Utica are major targets for thermogenic and biogenic production curves for each bin. Heterogeneity in the retardation factor (R) led to in Michigan, New York, Pennsylvania, and Quebec. Age-equivalent heavy tailing of breakthrough curves as the experiments progressed. shales extend into southwestern Ontario (Findlay Arch region), This non-Fickian transport behaviour was described using a continuous time random walk (CTRW) model designed to address where there has been no shale gas production to date and little variability in geochemical properties controlling sorption-desorption information exists on the origin and distribution of natural gas, kinetics. Results of this study demonstrate that the effects of NOM despite historical accounts of gas in water supply wells screened in compositional heterogeneity on transport can be addressed through a shales. To determine the origin and extent of natural gas, and systematic coupling of geochemical and hydrologic approaches. investigate water quality associated with natural gas occurrences, 912 water supply wells were sampled for gas composition, isotopes, and water chemistry in Paleozoic bedrock and overburden formations throughout southwestern Ontario. Methane concentrations, measured at the well head, ranged from <5 to 415% in-situ saturation (0 to ~251 ppm) with the highest concentrations in wells screened in the Georgian Bay, Dundee, Marcellus, Hamilton Group, and Kettle Point formations, and

overlying glacial drift deposits. Carbon isotopes values of CH4 (-

89.9 to –52.3‰), the correlation of hydrogen isotopes of CH4 and

water, and the lack of higher chain hydrocarbons (C2+<0.8 mole%), indicates the gas is biogenic in origin. Isotopic signatures of methane in overburden deposits were similar to gas accumulations in underlying bedrock formations, suggesting the gas migrated vertically into shallow aquifers, rather than being generated in-situ. Groundwater associated with methane accumulations are dominantly

Na-HCO3 type, with no dissolved oxygen, low Fe (<0.06 mM), low

SO4 (<0.44 mM), and low H2S (<0.5 mM). Alkalinity concentrations ranged from 0.2 to 15.0 mM, and there was no

correlation with CH4 concentrations. High CH4 concentrations were observed in groundwater with variable G18O values (-18.6 to –8.3‰), representing microbial methanogenesis associated with both modern and Late Pleistocene recharge. Results from this study provide important baseline data on dissolved gases and water quality in shallow aquifers overlying shales, in the case of future shale gas production, hydraulic fracturing and/or geologic sequestration of carbon dioxide to evaluate potential environmental impacts.

Mineralogical Magazine | www.minersoc.org 2092 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Anatexis and uranium protore in the Mineral and element vectoring in the Wollaston Domain, Saskatchewan Pilley’s Island VMS district, 1,2* 2,3 CHRISTINE L. MCKECHNIE , IRVINE R. ANNESLEY , AND Newfoundland Appalachians, Canada 2 KEVIN M. ANSDELL 1* 1 2 C.P. MCKINLEY , S.J. PIERCEY , L. WINTER , AND J.G. 3 1 CanAlaska Uranium Ltd., Saskatoon, [email protected] (* THURLOW presenting author) 1Department of Earth Sciences, Memorial University of 2 Department of Geological Sciences, University of Saskatchewan, Newfoundland, St. John’s, Canada, [email protected] Saskatoon, Canada, [email protected] (*presenting author), [email protected] 3 JNR Resources Inc.., Saskatoon, Canada, [email protected] 2Altius Minerals Corporation, St. John’s, Canada,

[email protected] The Fraser Lakes Zone B U-Th-REE-bearing granitic pegmatites 3Corner Brook, Canada, [email protected] are located within the Wollaston Domain of northern Saskatchewan, Canada. The mineralized zone lies circa 25 km from the A major challenge in ancient volcanogenic massive sulfide southeastern edge of the highly prolific Athabasca Basin; home to (VMS) districts is that many have been strongly affected by some of the world’s highest grade uranium deposits. metamorphism and deformation, resulting in mineralization being The granitic pegmatites intruded into a NNE-plunging regional hosted within imbricated, thrust-faulted terranes, with abundant fold structure at/near the highly deformed contact between Archean stratigraphic offset and juxtaposition. In such environments, barren orthogneisses and overlying Paleoproterozoic metasedimentary volcanic units are often juxtaposed next to those that may be VMS- rocks of the Wollaston Group.[1,2,3] Their intrusive contacts bearing, causing difficulty in stratigraphic reconstruction and in the suggest the pegmatites formed during the later stages of the ca. 1.8 discrimination of prospective from less prospective stratigraphy. Ga Trans-Hudson Orogeny.[1,2,3] This agrees with CHIME dating of These stratigraphic and structural uncertainties result in the uraninite in the uranium-rich pegmatites (a cluster of ages between requirement for the integration of lithogeochemistry and detailed 1.85 and 1.80 Ga). A primary magmatic age has yet to be determined mineralogy with traditional mapping, to vector towards for the Th-LREE-rich pegmatites, which have contact relationships mineralization at the prospect and regional scale. Pilley’s Island, similar to the strongly U-rich pegmatites. High-grade Newfoundland is an ideal location to demonstrate this vectoring metamorphism and migmatization occurred concurrently with because it hosts several VMS deposits in a small area (10 km2), it is pegmatite intrusion, at peak temperatures of up to T ca. 850°C at P heavily faulted with barren mafic volcanics thrust between VMS- ca. 9 kbar (i.e. lower granulite facies) followed by retrograde bearing felsic volcanic panels, and has excellent surface exposure amphibolite-facies metamorphism. and archived drill core for detailed geological and geochemical A combination of partial melting of a metasedimentary- visualization. dominated source at depth, accessory mineral entrainment, and Results from mapping, lithogeochemistry, and shortwave assimilation-fractional crystallization processes during ascent and infrared-near infrared (SWIR-NIR) spectroscopy have identified emplacement is thought to be responsible for U, Th, and REE alteration haloes around the VMS deposits of Pilley’s Island. The enrichment of the granitic pegmatites. distribution of AlOH, FeOH, and MgOH hull absorption values from These pegmatites show similarities to the alaskite-hosted SWIR-NIR spectra defines, from proximal to distal to uranium deposits at Rossing (Namibia) and to uraniferous mineralization, haloes of illitic phengite, phengite, illitic muscovite, pegmatites in the Grenville Province (Canada).[1] Similar muscovite, and Fe- to Fe-Mg- to Mg-chlorite. Surface and 3D pegmatites have also been found in the proximity of some of the gridding of lithogeochemical data have also identified prospective Athabasca Basin basement-hosted unconformity-type uranium zones for mineralization. In particular, useful vectors include Na, K, deposits, including Moore Lakes, Eagle Point, and Millennium. and alteration indices. For example, zones with highest Na depletion, Hence, it has been proposed [4,5,6,7] that such pegmatites are with K addition and associated with illitic phengite alteration are protore for the formation of these uranium deposits in the Athabasca most prospective for sulfide mineralization. Basin. Hydrothermal alteration (i.e. chlorite, hematite, and clay Despite this VMS district being intensely imbricated, the minerals) similar to that in the alteration halos around some of the integration of mapping, drill core reconstructions, Athabasca deposits is also found at Fraser Lakes Zone B [1,2,3,7], lithogeochemistry, and SWIR-NIR spectroscopy readily indicating that fluids of similar composition may have passed distinguishes the mineralization-related thrust faulted panels from through the pegmatites.[7] The presence of younger, secondary, those that are barren of mineralization. The integration of both hydrothermal U mineralization within fractures cutting the geochemical and mineralogical vectoring methods exemplified at pegmatites also supports this hypothesis. Pilley’s Island, can be useful in the exploration and delineation of VMS and other hydrothermal deposits elsewhere in the Appalachians [1] Austman et. al. (2010) SEG 2010 Conference Abstr. Ext. Abstr. and in other heavily faulted collision zones worldwide. F-1. [2] Annesley et. al. (2010) GeoCanada 2010 Abstr. No. 815. [3] Annesley et. al. (2010) SGS Open House Abstr. Vol. 2010, 8. [4] Annesley et al. (2000) Sask. Geol. Survey Sum. of Invest.2000 Vol. 2, 201-211. [5] Hecht & Cuney (2000) Miner. Deposita 35, 791-795. [6] Mercadier et. al. (2010) Lithos 115, 121-136. [7] Mercadier et.al. (submit.) Econ. Geol.

Mineralogical Magazine | www.minersoc.org 2093 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Carbon Dioxide Groundwater Reconstructing the large-scale deep Mixing and Mineralization Reactions and intermediate ocean circulation in with Reservoir Rocks at a Natural the North Atlantic during the LGM Analogue Site, Soda Springs, Idaho, and last deglaciation 1* 1 USA JERRY F. MCMANUS , SHARON S. HOFFMANN , 1 2 2 1 3 TRAVIS L. MCLING *, ROBERT W. SMITH , AND WILLIAM NATALIE ROBERTS , GENE HENRY , LOUISA BRADTMILLER , 4 5 6 SMITH3, KAIS MOHAMED , SAM JACARD , JIMIN YU , 2 7 7 1 ALEX PIOTROWSKI , DELIA W. OPPO , WILLIAM B. CURRY , Idaho National Laboratory-Center For Advanced Energy Studies, 8 9 SUMMER K. PRAETORIUS , AND LAURA F. ROBINSON Idaho Falls, ID, USA, [email protected]*. 2 University of Idaho-Center for Advanced Energy Studies, Idaho 2Lamont-Doherty Earth Observatory of Columbia University, NY, Falls, ID, USA, [email protected] USA [email protected] (* presenting author) 3Idaho State University, Pocatello, Idaho, USA, [email protected] 2University of Cambridge, Cambridge, UK, [email protected] 3Macalester College, St. Paul, MN, USA, [email protected] Analogue sites are particularly relevant and useful to the study 4University of Vigo, Vigo, ES, [email protected] geologic carbon dioxide sequestration for a number of reasons, 5ETHZ, Zurich, CH, [email protected] particularly because they offer the opportunity to examine a system 6Lawrence Livermore National Laboratory, CA, USA, [email protected] that has operated on a time scale (centuries to eons) that laboratory 7Woods Hole Oceanographic Institution, USA, [email protected] and field experimentation (days to decades) cannot compare. One 8Oregon State University, Corvallis, [email protected] such example of a mafic rock CO2 analogue is the Soda Springs site 9University of Bristol, Bristol, UK, [email protected] located in Caribou County of Southeastern Idaho, USA. At this site,

CO2 and formation fluids generated by the dissolution of Paleozoic The large-scale subsurface circulation of the ocean is an carbonates at depth are migrating and reacting with a series of important component of the Earth’s climate system, and contributes shallower thoelitic basalt flows that host a fresh water aquifer. We to the global and regional transport of heat and mass. More than two believe that the layered basalt flows are acting as a reactive barrier to decades ago, geochemical analyses of deep-sea sediments in the

the vertical migration of the deep CO2 charged fluids. However, in Atlantic Ocean revealed that the distribution of water masses and

several cases the CO2 charged reservoir fluids make it to the surface their characteristics were significantly different at the LGM and and are expressed as either carbonated springs, or as cold-water other times in the past when compared to modern observations. geysers caused by wells that encounter the system at depth. Analysis Although some of the paleodata have been reproduced and shown to of these sources of water shows a steady evolution of groundwater be robust, there has been continued debate about the implications of from unaffected by the basalt (deep wells) to more fully reacted these results for the dynamics of the large-scale circulation and the (springs). consequences for the storage and transport of heat, freshwater, Data from this system makes a compelling argument for the nutrients and carbon in the past. There is also no consensus on the ability of basalt flows to maintain containment for CCS applications. variations in water mass and dynamics that occurred between the Our study has shown that CO2 charged fluids migrating upwards are LGM and the establishment of the modern Atlantic circulation being neutralized by mineral dissolution and precipitation within the despite the development of time series and maps of more than a half basalt flows. These neutralization reactions have resulted in a dozen paleo proxies for various aspects of the circulation. specific chemical signature being imparted to the formation fluid that Here we present a discussion of new and previously published can be used to determine which minerals are dissolving and Pa/Th, G13C, SS, HNd, '14C, Cd/Ca, B/Ca, Zn/Ca and other data. We precipitating. Through and integrated study of this natural analogue consider which aspects of past circulation during the LGM and site including field and laboratory experiments, the relative roles of deglaciation are robustly established and which remain open to mineral dissolution and precipitation and phase assemblage are being competing interpretations. These results combine to confirm that characterized for this basalt-hosted system. the Atlantic circulation was different both in terms of water masses The benefit of studying this natural analogue is that it has been and their fluxes. The LGM Atlantic was characterized by rapidly active for many 1000’s of years and depending on sample location overturning intermediate waters, consisting of more than one water and depth, the resulting fluid chemistry carries the chemical signature mass, most likely of northern origin, and southern-sourced deeper (tracer) indicative of the degree of reaction within the basalt waters with a longer residence time in the basin. Early in the formation. Additionally, the study of this system is helping define deglaciation, during the H1 iceberg discharge and ensuing stadial, the appropriate laboratory scale experiments that will be needed to the boundary between intermediate and deep water masses shoaled, accomplish the larger objective of the project, understanding changes although a shallower overturning cell persisted throughout. We seek in aqueous geochemistry associated with progressing CO2-water- to reconcile apparently conflicting new and existing proxy evidence interactions. regarding any substantial change in the rate of deep water production and residence time during H1. Shortly after 15 ka, nearly all proxies indicate a rejuvenation of deep overturning, followed by a reduction during the Younger Dryas event (12.7 – 11.5 ka), and the subsequent development of the modern Atlantic circulation in the Holocene.

Mineralogical Magazine | www.minersoc.org 2094 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts

FROM RHIZOSPHERE TO ECOSYSTEM: Siqueiros Transform MORB; HEAVY METALS AND PLANT DEFENSE characteristics of a S-saturated suite 1* DAVID H. MCNEAR JR. 1 1* ANDREW MCNEILL , LEONID DANYUSHEVSKY , KEVIN 1 2 3 4 Unvieristy of Kentucky, Lexington, U.S.A., [email protected] KLIMM , ALEXEI ARISKIN , MIKE PERFIT

1 Human use and manipulation of our natural resources, CODES, University of Tasmania, Hobart, Australia, especially since the industrial revolution, has accelerated the [email protected] (* presenting author) 2 introduction of HM’s into soils resulting in a dramatic increase in Johann Wolfgang Goethe University, Frankfurt, Germany, their concentration in many soils of the United States (and beyond). [email protected] 3 Many of these HM’s even at very low concentrations are toxic and Vernadsky Intstitute, Moscow, Russia, [email protected] 4 reside in sites that are close to large and often socially downtrodden University of Florida, Gainesville, USA, [email protected] populations, and hence, pose a significant threat to both human Geochemically diverse mid-ocean ridge basalts, with a significant health and the environment. Few remediation technologies have range of major and trace element contents in pillow-rim glasses, been effective at treating HM enriched soils in-situ. were recovered from the Siqueiros Transform Fault, in the East Phytoextraction, the use of specialized metal hyperaccumulating Pacific Ocean. All these glasses were S-saturated at eruption, on the plants to remove metals from soils has been growing in popularity basis of the presence of immiscible sulfide globules (Fig. 1A). because it overcomes many of the limitations of conventional Based on the compositions of silicate melt inclusions in early- remediation methods. address the ecological implications that could crystallised olivine phenocrysts, previous workers [1] have interpreted the early Siqueiros liquids, which were less fractionated arise from planting non-native plants capable of transferring metals than the pillow-rim glasses, to be S-undersaturated. However, since from the soil to the shoots of the plant where they can then be we have observed numerous inclusions of immiscible sulfides in the introduced into the food chain, and/or have undesirable effects on same early olivine phenocrysts, we interpret that most of Siqueiros ecosystem structure and function. parental liquids were S-saturated early in their fractionation history. Elucidating how metals in specialized metal hyperaccumulating The compositions of these immiscible sulfide liquid inclusions in plant tissues influence plant physiology and insect feeding behavior olivine are consistent with those from other MORB suites [2] and is fundamental to understanding the evolution of this unique trait and estimates of sulfide liquid compositions from mantle rocks (e.g., [3]). In the Siqueiros samples S-Saturation appears to be largely the influence these plants may have on ecosystem structure and independent of liquid composition over a wide compositional range, function. The elemental defense hypothesis (EDH) states that and is only controlled by total Fe content (Fig. 1B). metals taken up and stored are effective at protecting plants from insect herbivores because of the inherent toxicity or unpalatability of the metals. A concomitant hypothesis, known as the trade-off hypothesis, states that plants will trade more physiologically costly chemical defenses (e.g. glucosinolates (GL’s)) for less costly metal defenses. The objectives of this study were to investigate these hypotheses by examining the spatial and temporal relationship between Zn and GL concentration and speciation in leaves of the model Zn hyperaccumulator Noccaea caerulescens (formerly Thlaspi caerulescense) and assess how these patterns influence insect feeding behavior. A six week greenhouse study was conducted with N. caerulescens grown in soil receiving 250, 500 Figure 1: A; reflected light image of a ‘quenched’ immiscible and 1000 uM Zn treatments. At the end of the experiment whole sulfide globule in pillow-rim glass. B; relationship between FeOt plant metal concentrations were determined in addition to the (all Fe as FeO) and S for Siqueiros Transform Fault pillow-rim analysis of young, medium and old leaves for total metal content glasses. The strong correlation indicates S-saturation (see [4]). (ICP-MS), total GL’s (as glucose) and GL species (HPLC). Metal Laser Raman analyses, using the method of [5], of primitive and distribution was also determined in young, medium and old leaves evolved pillow-rim glasses indicate that all S is present at S2- and using synchrotron based x-ray fluorescence (SXRF) mapping and that the maximum fO2 is therefore close to QFM. Mössbauer scanning electron microscopy (SEM-EDX), and the spatial analyses are being completed to confirm the fO2 of the pillow rim distribution of specific GL’s determined using matrix assisted laser glasses. desorption time of flight mass spectrometry (MALDI TOF/TOF MS) Our data from the erupted basalts and inclusions provides a well chemical mapping. The influence of these patterns on insect feeding constrained natural dataset that has been combined with behavior was assessed using the generalist herbivore Trichoplusia ni experimental data to produce a new sulfur saturation model [6] and can be used to test the results of this and other models. (Cabbage looper) in choice and no-choice feeding experiments.

Preliminary results show that the concentration and distribution of [1] Saal et al. (2002) Nature 419, 451-455. [2] McNeill et al. Zn in young, medium and old leaves is inversely proportional to that (2009) Proc. Xi’an Int. Ni-Cu Deposit Symposium., 4-5. [3] Luguet of GL’s with the younger leaves having a higher GL content than et al. (2003) Geochim et Cosmochim acta 67, 1553-1570. [4] older leaves. Feeding patterns are alterned in response ot Zn Wallace and Carmichael (1992) Geochim et Cosmochim acta 56, concentrationa and distribution in the leaves providing evidence for 1863-1874. [5] Klimm et al. (submitted). [6] Bychkov et al. (2010) the trade-off hypothesis. 13th IAGOD Symposium, 304-305.

Mineralogical Magazine | www.minersoc.org 2095 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts A Microbial Fuel Cell enhances Comparing the soil solution Bioremediation of Gasworks chemistry of soils amended with Contaminated Groundwater nano-sized copper oxide, micron- sized copper oxide, and with a B. MC POLIN1*, R. DOHERTY1, M.J. LARKIN2 copper salt.

1 Environmental Engineering Research Centre, SPACE, Queen’s HEATHER MCSHANE1,*, JOANN K WHALEN1, GEOFFREY University Belfast (*correspondence: [email protected]), SUNAHARA2, WILLIAM HENDERSHOT1 ([email protected]) 2 School of Biological Sciences, Medical Biology Centre,

Queen’s University Belfast ([email protected]) 1 University of McGill Dept. of Natural Resource Sciences, Ste Anne Microbial Fuel Cell (MFC) technology has been applied to de Bellevue, Quebec, Canada, [email protected] many different remedial technologies, including bioremediation (* presenting author) of contaminated groundwater. As of yet full scale 2: National Research Council Canada - Biotechnology Research implementation of the technology in relation to remediation Institute, Montreal, Quebec, Canada, geoffrey.sunahara@cnrc- projects has not been proven. In regards to groundwater nrc.gc.ca bioremediation a MFC consists of bacteria oxidising contaminants such as organic pollutants within an anaerobic area of a plume (the anode) and the transfer of electrons through a Engineered copper oxide nanoparticles (nano-CuO) are likely to circuit to a cathode where terminal electron acceptors are be used in agriculture in the future but little is known about their reduced. This results in the generation of a low current and the effects on soil biota. As nano-CuO particles dissolve, they release depletion of contaminants. Cu2+, which can be measured as Cu activity, and which is thought to From geophysical analysis a large MFC (50+mV) was be the main form of bioavailable Cu in soils. Copper bioavailability observed to be functioning at a gasworks site containing high levels of organic and ammonium contamination in groundwater. may change over time as the Cu redistributes between soil solid and 2+ The aim of this research is to investigate what parameters play a solution phases. Soluble Cu salts have been used to evaluate Cu role or drive the MFC and can it be utilised as a sustainable transformations but they can reduce soil pH and increase the remediation tool. concentration of dissolved cations in the soil solution, and they may Experiments involve constructing a MFC with graphite overestimate bioavailable Cu. In this study, we amended two natural electrodes connected by wire that provides a direct circuit from high contamination (the anode) to an area of bioelectric activity soils with 500 mg Cu / kg soil as nano-sized or micron-sized CuO, or (the cathode). A variable resistor and datalogger are used to as Cu nitrate, and measured the change in Cu activity, pH, and monitor current production. Comparison of water samples using concentrations of dissolved Ca, Mg, and Zn in the amended soils over chemical analysis (monitoring levels of TOC, Ammonium, a period of 56 d. The initially low Cu activity in the oxide-amended Nitrate & Nitrite) and molecular microbiology techniques soils increased over the course of the experiment, whereas the (characterising the microbial population at the anode and initially high Cu activity in the salt-amended soil declined. Soil pH cathode using PCR, DGGE, and metagenomics approaches) before and after electrode operation would indicate whether the was lower and dissolved cation concentrations were higher in the MFC has enhanced bioremediation. Initial results indicate salt-amended soils than in the oxide-amended soils for the duration of considerable microbial diversity between the anode and cathode the experiment. We conclude that amending soils with Cu nitrate on site and a large Self-Potential (electrical) difference. There is does not accurately reflect Cu2+ transformations in soils amended also evidence of microbial utilisation of ammonium. with nano- and micron-sized CuO. Genetic analysis of the shift in microbial population before and after MFC installation would highlight the involvement of microbes in the bioremedial process. Characterising the microbial biofilm formed at the anode and cathode would give a better understanding of the role the active microbial communities play in electrical conductivity and ultimately a better understanding of the potential bioremedial/ bioelectric potential of the native microbial consortia which can be exploited for bioremediation.

Mineralogical Magazine | www.minersoc.org 2096 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts In-situ geochemical characterization Pumping away: Impact of benthic of experimental partial melts macrofauna on flow, redox dynamics 1,2* 3 FIONA C. MEADE , MATTEO MASOTTA , VALENTIN R. and sediment N cycling 2 4 2 TROLL , CARMELA FREDA , BÖRJE DAHRÉN , JON P. 1,* 1 2 3 5 6 C. MEILE , T. DORNHOFFER , S. KAZA , N. VOLKENBORN DAVIDSON AND ROBERT M. ELLAM 4 AND G.G. WALDBUSSER 1University of Glasgow, Glasgow, UK, [email protected] 1Dept. of Marine Sciences, The University of Georgia, Athens, GA (* presenting author) 30602, USA, *[email protected], [email protected] 2Uppsala University, Uppsala, Sweden, [email protected] 2Institute for Artificial Intelligence, The University of Georgia, 3Sapienza Università di Roma, Rome, Italy, Athens, GA 30602, USA, [email protected] [email protected] 3Dept. of Biological Sciences, University of South Carolina, 4INGV, Rome, Italy, [email protected] Columbia, SC 29208, USA, [email protected] 5Durham University, Durham, UK, [email protected] 4College of Oceanic and Atmospheric Science, Oregon State 6SUERC, East Kilbride, UK, [email protected] University, Corvallis, OR 97331, USA,

[email protected] Understanding partial melting of ancient gneiss terranes is crucial when considering crustal contamination in volcanic systems, Burrowing organisms have long been recognized to play a major for example, as these rocks are unlikely to melt completely at role in biogeochemical cycling in aquatic sediments. However, only magmatic temperatures (900-1200 °C) and crustal pressures (<500 recently have advances in sensor developments and computational MPa). Variations in the bulk composition of the protolith, magma capabilities provided the opportunity to detail the flow dynamics and temperature, pressure (depth), the composition and abundance of any oscillatory redox conditions driven by the pumping activity of fluids present will produce a variety of melt compositions. This may benthic infauna. Here we present a coupled flow-reaction model range from partial melts enriched in incompatible elements to more analysis linked to observations in experimental microcosms. complete melts, nearing the bulk chemistry of the parent gneiss. While volumetric pumping rates are fairly well known and We have used piston cylinder experiments to simulate partial experimentally accessible, flow patterns in the subsurface are not. melting in a suite of 10 gneisses from NW Scotland and Eastern However, they are important to quantify location and extent of oxic- Greenland at magma chamber temperatures and pressures (P = 200 anoxic interfaces which are critical in determining the MPa, T = 975 °C). These gneisses form the basement to much of biogeochemical cycling of redox sensitive elements. We present the the North Atlantic Igneous Province, where crustal contamination is determination of such velocity fields using optical flow anlysis of frequently identified. However, the actual compositions of the fluorescent dye tracers in antfarm experiments. crustal partial melts are poorly constrained. Partial melts were Our work then focuses on the role of burrowing organisms on produced in all 10 experiments. The experimental charges were O2 dynamics and nitrogen cycling in coastal sediment. We will quenched so that partial melts were preserved as glass, making them present model analyses of the impacts of burrowing depth, irrigation suitable for in-situ microanalysis. Electron microprobe spot intensity and activity patterns. Our results show a distinct role for all analyses of the glasses indicate they are compositionally these factors on denitrification. Model simulations show a heterogeneous and are significantly different to the bulk chemistry significant impact of volumetric water exchange on areal of the parent gneisses. The samples were mapped using energy- denitrifaction; notably, they also predict a different trajectory of dispersive x-ray spectroscopy (EDX), which deciphered the spatial total denitrification with increasing burrow depth for continuous vs. variation in melt chemistry and revealed evidence of intense mixing episodic biologically induced flow. and mingling processes. Individual melt domains were microdrilled Our findings have significant implications for removal of N for Sr and Pb isotope ratios. from shallow water environments, and the controls thereof. Initial This novel petrological, experimental and in-situ geochemical results suggest that nitrate removal is controlled not only by spatial approach allows quantification of partial melting in a volcanic structuring of the sediment (e.g. concentration gradients), but also context, providing accurate geochemical end-members for by temporal dynamics (duration and frequency) of anoxic conditions modelling crustal contamination processes. forming in the sediment domain. Our findings also suggest that bioirrigation models which depict organism activity as an averaged continuous, unidirectional process miss the temporally dynamic character of biologically active sediments that may profoundly affect sediment nitrogen cycling.

Figure 1: BSE image and EDX map of a partial melting experiment showing heterogeneous composition and mixing/mingling textures. Images and analyses were collected using the FE-EPMA facility at Uppsala University (http://www.geo.uu.se/mpt).

Mineralogical Magazine | www.minersoc.org 2097 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Behavior of uranium isotopes in Low energy absorption edges of NS3 shallow aquifers of southern Québec, glass, albite and silicon investigated Canada using x-ray Raman scattering

1 3 1* 1 PAULINE MÉJEAN , GENÈVIEVE VAUTOUR , DANIELE L. KOLJA MENDE , ALEXANDER NYROW , CHRISTIAN 4 2, 5 1 2 2 PINTI , BASSAM GHALEB MARIE LAROCQUE STERNEMANN , CHRISTIAN SCHMIDT , MAX WILKE , LAURA 3 3 1 1,2,3,4,GEOTOP-UQAM, Montréal, QC, Canada SIMONELLI , MARCO MORETTI SALA , CHRISTOPH SAHLE , 1 4 1 1 [email protected] (* presenting author) THORSTEN BRENNER , JOHN TSE AND METIN TOLAN 2 [email protected] 1 3 [email protected] Fakultät Physik, TU Dortmund, Dortmund, Germany 4 [email protected] *[email protected] 5 Département des Sciences de la Terre et de l’Atmosphère, UQAM, 2Geoforschungszentrum Potsdam, Potsdam, Germany Montréal, QC, Canada 3European Synchrotron Radiation Facility, Grenoble, France 5 [email protected] 4Department of Physics and Engineering Physics, University of

A multi-isotopic study was initiated in order to quantify the Saskatchewan, Saskatoon, Canada

groundwater resources available in a shallow aquifer of southern 234 238 X-ray Raman Scattering (XRS) Québec. Uranium content and its isotopes U and U, which are partially dependent of redox conditions and physical/lithological The investigation of processes of geological relevance is characteristics of the aquifers and their recharge were measured. In directly connected to environments of extreme conditions, e.g., high specific cases, 234U/238U activity ratios can give information on the pressure and high temperature. For in situ studies of materials under residence time of groundwater, a fundamental piece of information such conditions one needs to use special sample chambers with for a correct estimation of groundwater sustainability. highly absorbing sample environments such as diamond anvil cells, The target area is the lower portion of the Bécancour River which prevent the use of electron or soft x-ray techniques like EELS watershed located between Montréal and Québec. Groundwater flows or XANES, combined with laser or resistive heating. in shallow sands intercalated with clays of the Champlain Sea XRS is a non resonant inelastic photon-in-photon-out scattering (Holocene age) and deeper fractured carbonates of Ordovician age of process. The incoming high energy photons are scattered by core- the St. Lawrence Lowlands. Water chemistry is dominantly hole electrons, exciting them to unoccupied states by transferring a bicarbonate. relatively small amount of energy [1]. The application of hard x-rays Two transects (15 wells) were preliminary selected. The first makes x-ray Raman scattering a unique tool to investigate low follows the main flow path from the Appalachian Mts. (the main energy absorption edges for binding energies between 10 eV and 2 recharge area) downstream to the St. Lawrence River. The second keV of low Z elements like silicon, sodium, iron or oxygen under transect is perpendicular to the first one and contains more geologically relevant conditions. mineralized waters. Along the flow path, there is a clear decreasing XRS is very sensitive to changes of the electronic and local 234 238 trend of the U/ U activity ratio, from a maximum of 3.12 atomic structure, e.g., the oxidation or spin state of the studied atom. measured close to the recharge to a value of 1.14, on the plain next to It provides the similar information as soft x-ray absorption and the St. Lawrence River. electron energy loss spectroscopy. During decay of 238U to 234Th, an
particle is emitted. The recoil

energy is sufficiently important for the mineral to eject 234Th to NS3 glass, albite and silicon groundwater or to weak mineral sites were 234U will be produced, Silicon is the subject of many current studies. These include making it easily leachable. Consequently, recharging groundwater would be enriched in 234U when compared to 238U and this silicate melts and glasses due to their geological relevance, as well mechanism might explain the high 234U/238U activity ratios observed as pure silicon [2,3]. We present first results of an XRS study of the close to the recharge areas. sodium K-edge of dry and water bearing NS3 glass (Na2Si3O7) and The observed decrease of the 234U/238U ratio along the flow path albite (NaAlSi3O8) as well as results on the aluminum L-edge of could be interpreted by the radioactive decay of the excess of 234U albite. Furthermore we show recent in situ measurements of pure compared to that of 238U at the 234U time scale (106 yrs). However, a silicon at the Si L-edge at pressures up to 20 GPa. recent noble gas survey shows clearly that groundwater in the recharge area contains tritiogenic 3He with ages younger than 20 [1] Schülke (2007) Electron Dynamics by Inelastic X-ray years. A different process should be evoked to explain the isotopic Scattering (Oxford University Press) fractionation of 234U/238U. There is a clear relation between the [2] Weigel et al. (2008), J. Phys.: Condens. Matter 20, 135219 - 234 238 [3] Farges et al. (2006), AIP Conf. Proc. 882, 214-216 alkalinity of waters (and the HCO3 content) and the U/ U activity ratio. This relation suggests that the mobility of uranium might be - 2- related to HCO3 and CO3 ions complex. It is known that carbonates and hydroxyls could be efficient agents of complexation inducing higher mobility of 234U after the “recoil”. Thus the high activity ratios observed could be related to the enhanced mobility of 234U in bicarbonate waters.

Mineralogical Magazine | www.minersoc.org 2098 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Greener and leaner soil and sediment Origin of uranium deposits revealed remediation: an overview of in-situ by their rare earth element signature 1 CHARLES MENZIE JULIEN MERCADIER*, MICHEL CUNEY, PHILIPPE

1 LACH, MARIE-CHRISTINE BOIRON, JESSICA Exponent Inc., Alexandria VA, USA, [email protected] BONHOURE, ANTONIN RICHARD Abstract G2R, Université de Lorraine, CNRS, CREGU, 54506 Vandoeuvre- Over the past decade there has been heightened interest in using lès-Nancy, France (*[email protected]) in-situ remediation for contaminated sediments and in-situ technologies for soils have been underway for the past few decades. Uranium deposits have formed in a wide range of geological Such technologies include methods for degrading the contaminants in settings including deep metamorphic/magmatic to surficial place or arresting or blocking exposures through the use of various conditions and range in age from Archean to recent time. These barriers and amendments. These approaches appeal to common sense temporal and spatial variations have given rise to an extreme as they can be less costly to implement, can be less disturbing to the diversity of deposits [1]. However, understanding their genesis and exploring for uranium deposits have remained challenging. In environment, and may pose lower risks to humans. But often the particular, very limited link between trace element or isotopic arguments regarding pros and cons of in-situ vs. removal composition of uranium oxide and the conditions for their technologies focus on specific aspects of the remedial process. What accumulation to economic grades have been clearly established. can be lost in narrow arguments is the fuller understanding of the life Here we report REE abundances in uranium oxides, measured by cycle of the various technologies with respect to overall economic, microbeam methods (SIMS and LA-ICP-MS), for a series of 20 environmental, and human health benfits. worldwide uranium occurrences from six of the major uranium The economic benefits aspects are often the easiest to grasp and deposit types. This study demonstrates that the REE contents of uranium oxides are very specific to each deposit type, regardless of to compare among removal and in-situ remedial technologies. Less the age or variations in local geological settings. Thus, REE obvious are overall ecological benefits. Understanding relative abundances reflect directly the mineralising processes specific to ecological benefits typically requires a broad understanding of the each deposit type. We propose an evaluation of the first order ecological risks/impacts that contaminants are having within the parameters (T, REE sources and fluid composition) controlling the system, the degree to which these risks will be reduced in the short REE behaviour in each mineralized system. When applied to giant and long-term by the remedial technologies, and the short and long- unconformity-related deposits, REE abundances enable to better term impacts of the remediation. understand their formation. Our results demonstrate that the REE patterns of uranium oxides are powerful tools for refining A variety of methodologies have arisen to capture the metallogenic models, and a key for the definition of the genetic relative environmental risks and benefits of alternative technologies. model of new uranium discoveries [2]. These include Net Environmental Benefits Analysis (NEBA), Integrated Environmental Benefits Analysis (IEBA), and Relative Risk Methods (RRM). Implementation of these methods requires knowledge of the various ecological systems and associated ecological srvices. Relative human health risks and benefits involve a comparison of technologies in the short and long-term for the full range of remedial elements. Particular attention has been given to the life-cycle aspects that influence site-related risk reduction, potential risks associated with remediation, and even risks to remedial workers. While the last has gotten much discussion, it is important to note that “risk acceptability” is itself a variable that is not constant over all populations. This talk will weave together the above aspects into a consideration of the “greener” and “leaner” nature of in-situ remediation and the efforts that are needed to make that case.

Figure 1:chondrite-normalized REE patterns of uranium oxides for six different types of worldwide U deposits. Source : source of REE

[1] Cuney (2009) Mineralium Deposita 44, 3-9. [2] Mercadier et al. (2011) Terra Nova 23, 264-269.

Mineralogical Magazine | www.minersoc.org 2099 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Pre-eruptive conditions of ore- Experimental solubility of silica in forming magma that produced the nano-pores 1,* 2,3 Henderson molybdenite deposit, CO: LIONEL MERCURY , MAJDA BOUZID , JEAN-MICHEL 3 Insights from melt inclusions and MATRAY mineral thermobarometry 1 Institut des Sciences de la Terre d’Orléans, UMR 7327 Université d’Orléans/CNRS/BRGM, 1A rue de la Férollerie, 45071 1* 1 CELESTINE N. MERCER , ALBERT H. HOFSTRA , TODOR I. Orléans Cedex, France. (* presenting author) 1 1 TODOROV , AND ERIN E. MARSH 2 IDES, UMR 8148 CNRS/Université Paris-Sud, bâtiment 504, 1USGS, Denver, USA, [email protected] (* presenting author) 91405 Orsay cedex, France 3 IRSN, DEI/SARG/LETS, BP 17, 92262 Fontenay-aux-Roses

The Henderson ore body is a Climax-type porphyry cedex, France molybdenum deposit related to Oligocene high-silica rhyolite intrusions of the Red Mountain Complex near Empire, Colorado [1, We used a pressure membrane extractor (Model 1020, Soil 2]. The Hideaway Park rhyolite ashflow tuff outcrops 17 km NE of Moisture Equipment Corp.) to study the silica content at equilibrium the Henderson deposit, and is thought to be a co-genetic extrusive with the decreasing pore sizes of amorphous silica. The principle is expression of the intrusive complex that formed the Henderson to extract the aqueous solution through a sequential process from deposit [3, 4]. We use quartz-hosted melt inclusions and phenocryst the larger (micrometric) pores to the thinner (some nm) pores. Each mineral chemistry to place constraints on the pre-eruptive magmatic extraction step is followed by an equilibration period. The measurements confirmed earlier observations [1,2] that the conditions (P, T, fO2, fS2 ), volatile contents (H2O, CO2, F, Cl, S), and metal concentrations to better understand the process of metal concentration in dissolved silica decreases when the extraction segregation within Climax-type ore-forming stocks. pressure increases. The direct conclusion is that the silica solubility Melt inclusions in the Hideaway Park rhyolite are comprised of is pore-size dependent. These results are interpreted with the Young- glass, devitrified glass, crystals, and vapor. Crystals typically include Laplace relationship, at constant silica-solution surface tension, quartz, alkali feldspar, magnetite, fluorite, zircon, and monazite. No which means to attribute an elasto-capillary pressure to the solid. 1.0 molybdenite crystals have yet been identified within the crystallized inclusions, however some inclusions likely contain them because 1.0

preliminary trace element analysis by LA-ICP-MS reveals several calculated Si/Si°, Jsolid-water = 133 mJ/m² 0.9 inclusions with anomalously high Mo concentrations (15-115 ppm) )° 2 compared to the modal Mo concentration (10 ppm). 0.9 Accessory minerals in the Hideaway Park rhyolite include ) / (SiO magnetite, ilmenite, biotite, zircon, and monazite. Preliminary 2 0.8 (SiO calculated Si/Si°, J = 275 mJ/m² magnetite-ilmenite pairs indicate crystallization at an fO2 of 0.8 solid-water NNO+1.7 and an aTiO2 of 0.4 [6]. SEM-CL images of quartz phenocrysts show alternating bright- 0.7 6 nm 6 nm bis to-dark euhedral growth rims and resorbed zones. Ti concentrations 0.7 15 nm bis in quartz measured by electron microprobe range from 39 to 66 ppm Data from [1] corresponding to crystallization temperatures [7] between 720- 0.6 0.02 0.04 0.06 0.08 0.10 0.12 qC (assuming aTiO2 = 0.4 and a preliminary pressure estimate of -1 2 kbar, equivalent to a shallow crustal magma reservoir at ~6 km 1/rpore (nm ) depth). Quartz phenocrysts contain zircon inclusions, but pyrrhotite Figure 1: Decreasing silica solubility extracted from pores having and molybdenite inclusions have not yet been found in any decreasing radii. phenocrysts. Given that the Henderson deposit was formed in an The geological implication can be illustrated using a simple extensional tectonic regime, carries a deep crustal/upper mantle scheme (e.g. [3]), wherein aquifer compartments with changing pore signature (Mo/Rb = 0.013-0.040), and is only moderately oxidized, sizes are successively put along a flowing line (in series). Depending the magma is likely to be saturated with both molybdenite and on the modeling assumption (pore sizes, succession type, pyrrhotite [5]. Assuming pyrrhotite and magnetite saturation at equilibrium state of the solution), this process can result in a 750qC and an fO2 of NNO+1.7, the Hideaway Park rhyolite should preferential cementation of the thin or the large pores. saturate with molybdenite with 8 ppm Mo in the melt [5]. The modal Our experiments demonstrate that the negative curvature of the Mo value of 10 ppm may be indicative of a slightly higher average solids has a geochemical feed-back on the solid-solution crystallization temperature (+10-20qC) or a slightly higher interactions, with a threshold size at around 0.1 μm. prevailing fO2 of NNO+2. [1] Dandurand J.-L., Mizele J., Schott J., Bourgeat F., Valles V., and [1] Wallace (1978) B Soc Econ Geol 73, 325-368. [2] Seedorff Tardy Y. (1982) Sci. Géol. Bull. 35, 71−79. [2] Emmanuel S. and (2004) Econ Geol 99, 3-37. [3] Adams (2009) GSA Annual Berkowitz B. (2007) Geophys. Research Letters 34, L06404. [3] Meeting 93-7. [4] Geissman (1992) GSA B 104, 1031-1047. [5] Mizele J., Dandurand J.-L., and Schott J. (1985) Surf. Sci. 162, 830- Audétat (2011) J Petrol 52, 891-904. [6] Ghiorso (2008) Am J Sci 308, 957-1039. [7] Huang (in press) Geochim Cosmochim Ac. 837.

Mineralogical Magazine | www.minersoc.org 2100 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Carbon isotope diffusion in quartz & The use of trace elements in Fe-oxides apatite and its relationship to in deducing the fractionation history biosignatures of a silicate magma: A LA- 1,2 1 SEBASTIAN T. MERGELSBERG *, DANIELE J. CHERNIAK ICP-MS study 1,2 AND E. BRUCE WATSON

1* 1 1 2 1Department of Earth & Environmental Sciences, Rensselaer J. MERIC , S.A.S.DARE , S.-J. BARNES AND G. BEAUDOIN

Polytechnic Institute, Troy, NY 12180, USA (*correspondence: [email protected]) 1Université du Québec à Chicoutimi, Québec, Canada, G7H 2B1 2New York Center for Astrobiology, Rensselaer Polytechnic 2Université Laval, Québec City, Québec, Canada, G1V 0A6 Institute, Troy, NY 12180, USA

Knowledge of the trace element compositions of Fe-oxides While organisms live, their enzymatic reactions tend to will help to develop indicator minerals for exploration in addition to accumulate certain isotopes of particular elements more than others. improving our understanding of the petrogenesis of the deposit. This The most abundant element in any organism – carbon – is no study has characterized Fe-oxides, using laser ablation ICP-MS, exception and its lighter isotope is preferentially accumulated and from the upper part of Sept-Îles layered intrusion (Québec, Canada), incorporated, leading to a general δ13C of around -40.00‰ to - which hosts an Fe-Ti-P deposit, rich in magnetite, ilmenite and 10.00‰. When an organism dies, its remains may be taken up by a apatite. The Fe-oxides record a sequence of fractional crystallization growing host mineral, such as quartz or apatite. This inclusion would that evolves from the bottom to the top of the deposit. Trace “freeze” the ratio, creating a biosignature that is thought to be stable elements in both magnetite and ilmenite vary as a function of their over time. Most of the evidence for the earliest life forms on Earth stratigraphic position (Fig. 1). Aluminium, Co, Cr, Mg and V is found in the form of isotopic biosignatures. Durable and inert decrease in the Fe-oxides up sequence whereas Ga, Ge, Hf, Mn, Mo, minerals such as apatite and quartz are potential hosts for these Nb, W, Sc, Sn, Ta, Zr and Zn increase. These geochemical variations isotopic anomalies, but their ability to accommodate carbon is appear to be controlled by the partition coefficients of compatible uncertain, especially in the case of quartz. Recently, the origin and (e.g., V) and incompatible (e.g., Mo) elements into the co- validity of biosignatures have been questioned, suggesting abiotic crystallizing phases (olivine, plagioclase, magnetite, ilmenite and origins of lower δ13C isotope ratios [1] rather than being strictly apatite) and in the magma during fractional crystallization of the derived from enzymatic action. silicate magma. Although magnetite and ilmenite show similar To investigate the potential of apatite and quartz to record and variations (Fig. 1), elements partition differently between the two. retain biosignatures, the solubility and diffusion of different carbon For example, Hf, Mg, Nb, Sc, Ta, Ti, W, and Zr are more abundant in species in these minerals were investigated. Carbon is detectable in ilmenite whereas Al, Co, Cr, Ga, Ge, Mo, Ni, Pb, Sn and V are more both apatite and quartz treated at high temperature and pressure in 2- abundant in magnetite. the presence of graphite, CO, CO2, and CO3 . Regardless of primary

carbon species, however, the diffusion rates remained more or less

constant. In addition, the values seemed to line up quite well with

oxygen isotope diffusion data in quartz, when the diffusing species

was CO2 [2]. Based on these findings, it seems possible that the

primary diffusion of carbon in these minerals depends greatly on the

production of CO/CO2 and thus the oxygen fugacity in the system.

Recent studies of isotope fractionation in the production of

these gases from carbon indicate that CO production may lead to

great distortion of the isotope ratio in the parent material. Evidence

of such mechanisms would be suggesting a certain fallibility in

interpretating isotopic ratios as biosignatures and recognizing proof Figure 1: Variation of V and Mo in magnetite (Mt) and ilmenite of early life on earth. (Ilm) as a function of depth in the Fe-Ti-P deposit of Sept-Îles. The layered sequence comprises, from bottom to top: magnetitite (grey), nelsonite (yellow) and nelsonitic-gabbro (orange).

This study shows that the chemical composition of Fe-oxides varies over a wide range within a single Fe-Ti-P deposit as a result of fractional crystallization. Thus it is necessary to understand the processes that control the chemical variability of the Fe-oxides in any given deposit in order to develop an effective exploration tool [1] Horita, J (2005) Chemical Geology 218(1-2), 171-186. for the mining industry. [2] Sharp, ZD, Giletti, BJ and Yoder, HS (1991) Earth and Planetary Science Letters 107, 339-348.

Mineralogical Magazine | www.minersoc.org 2101 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Improved representation of dust- Influence of zostera meadows on nutrient deposition to the ocean for geochemistry and meiofauna of the the Earth System Models * sediment of a tidal lagoon (Arcachon MESKHIDZE , N. AND M. S. JOHNSON Basin): new technical approaches North Carolina State University, Raleigh, USA, 1* 2 *[email protected], [email protected] EDOUARD METZGER , DIDIER JEZEQUEL , EMMANUELLE 1 1 1 GESLIN , FLORIAN CESBRON , LAURIE CHARRIEAU , MARIE- 3 3 1 With the development of comprehensive Earth System Models LISE DELGARD , BRUNO DEFLANDRE , FRANS JORISSEN , AND 3 (coupled climate-carbon models with land and ocean PIERRE ANSCHUTZ biogeochemistry) there is an increased need for improved 1 representation of atmospheric fluxes of essential nutrients, i.e. iron Univ. Angers, LPGN-BIAF, OSUNA, Angers, France, (Fe), phosphorus (P), and nitrogen (N) to the surface oceans. These [email protected] (* presenting author) 2 micronutrients have a controlling effect on marine ecosystem Univ. Paris Diderot, Sorbonne Paris Cité, IPGP, France 3 productivity and therefore can influence the global carbon cycle and Univ. Bordeaux, EPOC, UMR 5805, Talence, France

climate. Today it is well established that models that consider Tidal lagoons are by definition very dynamic environments. interactive representation of aerosol-climate-carbon cycle do better Sediments from such environments are very heterogeneous job in predicting future climate. Since Fe at the dust source regions especially because of direct action of living organisms (i.e. is thought to be primarily in an insoluble form with increasing bioturbation). The intertidal flats of Arcachon basin are highly bioavailability through the interaction of mineral particles with covered by seagrass meadows of Zostera noltii. The seasonnal acidic trace gases, it is believed that anthropogenic activities may dynamics of these meadows enhance the lateral heterogeneity of the exert sizable influence on micronutrient fluxes to the ocean. sediment by influencing sedimentation and organic matter In this study the state-of-the-art dust-nutrient dissolution accumulation. The present study shows preliminary results from scheme has been implemented in the global 3-D chemistry transport very new techniques which were applied to understand the model GEOS-Chem. The Fe-dissolution module of Meskhidze et al. relationship between the root system of seagrass and meiofauna (2005) [1] was updated to consider dust-mineralogy in different such as foraminifera. Those are able to respire oxygen and nitrate as desert regions, Fe-organic acid (oxalate) interaction, the well as bacteria. Our hypothesis is that roots bring oxygen to the photoreductive dissolution of Fe containing minerals (hematite, anoxic sediment maybe generating nitrate-rich microenvironments. goethite and aluminosilicates), and the redox cycling between Since foraminifera are able to denitrify, we suppose that some relatively more soluble ferrous, Fe(II) and highly insoluble ferric, specialized taxa can gather in such environments. Fe(III) forms of iron. Dissolution of P containing minerals is carried Methodologically, our goals are: i) to document at a out using acid-based chemistry [2], while nitrate production occurs submillimetric scale and in 2 dimensions relevant redox species through the deposition of gas phase nitric acid on mineral dust. Our (e.g. H S, Fe(II), PO , NO ) in the pore waters using combined DGT- calculations using dust-nutrient dissolution scheme show high 2 4 3 DET gels and in the solid phase by X microflurescence; ii) to temporal and spatial variability in nutrient deposition fluxes over the describe foraminiferal species related to documented ocean. Preliminary results indicate (see Fig. 1) that simplified Fe microenvironments using a highly discriminant staining technique dissolution schemes, with the prescribed amounts of soluble iron, for living specimen (i.e. CTG fluorogenic probe). The metabolism are unable to capture the complex nature of micronutrient of anoxia tolerant taxa is quantified using microchambers equiped deposition to the surface ocean. Our study reveals that in order to with microsensors. properly account for the effects of anthropogenic activities on ocean biogeochemical cycles, next generation Earth System Models should consider implementation of more comprehensive modules for nutrient mobilization from mineral dust.

Figure 1: CTG Fluorescent foraminifera observed using an

epifluorescence binocular (left) and 2D DET images (right): H S in 2 brown, Fe(II) in pink and PO in blue 4

Figure 1: Percent difference (1% - model)/model in soluble Fe 2D DET gels show very heterogeneous redox layers which are deposition during January 2009. very influenced by burrowing organisms and seagrass root webs. The

[1] Meskhidze et al. (2005) J. Geophys. Res. 110, 1-23. first results seem to show that foraminferal densities are also [2] Nenes et al. (2011) Atmos. Chem. Phys. 11, 6265–6272. influenced by the root web related to sedimentary redox interfaces. Anoxic sediment is dominated by Eggerella sp. which ability to denitrify is presently being assessed in the laboratory.

Mineralogical Magazine | www.minersoc.org 2102 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts The source of Si in terrestrial plants: Nucleosynthesis and Isotopic Anomalies amorphous silica vs clay minerals in FUN CAIs

BRADLEY S. MEYER1* JEAN-DOMINIQUE MEUNIER*, MUHAMMAD RISWAN, JING 1Department of Physics and Astronomy, Clemson University, Clemson, SHA AND CATHERINE KELLER SC, 29634-0978, USA, [email protected] (* presenting author) Aix-Marseille Université, CNRS, CEREGE, Europôle Méditerranéen de l'Arbois, 13540 Aix-en-Provence, France, Introduction [email protected] Millions of stars working over Galactic history generated the mix of

isotopes present in the interstellar medium 4.6 billion years ago. Although Si is generally not considered as a nutrient for terrestrial plant, there are increasing evidences showing a beneficial effect of Importantly, each of the roughly 280 different naturally-occurring isotopes Si particularly under environmental stresses. Recent studies have in the Solar System had a different production route during this history, suggested that land use and particularly agriculture can modify the Si and present Solar System objects may contain a chemical memory of these cycle through a depletion of soil available Si. The extent of the varying histories [1]. Isotopes of Ca, Ti, Cr, Mo, and Ba in particular show perturbation, its impact on the plant cycle and food production is anomalies in primitive Solar System samples, which thus give evidence of challenging and requires a better assessment of the biogeochemical such chemical memory (e.g., [2]-[4]), and a key goal of isotope acquisition of Si by plant. Si accumulated in plants originates from cosmochemistry in the coming years will be to understand what these the dissolution of soil silicates. In soil solutions, Si is mostly anomalies are telling us about nucleosynthesis, Galactic chemical present as the neutral molecule Si(OH)4 (silicic acid). Si(OH)4 is absorbed by the roots by a mechanism that is not fully understood. evolution, and Solar System formation. Both active and passive uptakes have been evidenced. In shoots, Si(OH)4 is polymerized through the elimination of water by Neutron-Rich Iron-Group Isotopes and FUN CAIs evaporation and, eventually, phytoliths (amorphous opaline silica The anomalies in the neutron-rich iron-group isotopes found in FUN particles) form. Steady state models show that plants absorb a (fractionation and unknown nuclear effects) CAIs (calcium-aluminum-rich significant fraction of dissolved Si that originates from litterfall inclusions) present a long-standing example of a likely cosmic-chemical decomposition i.e phytolith dissolution. Laboratory experiments memory effect [2]. FUN CAIs show correlated excesses and deficits in the show that phytoliths are a source of silica amongst the most soluble 48 50 54 of the soil minerals at slightly acid to neutral pH. However, because isotopes Ca, Ti, and Cr. All three of these isotopes have substantial the concentration of phytoliths in soil is generally low (below 10 production in a low-entropy environment [5], most likely the mg/g), the contribution of clay minerals as a source of bioavailable thermonuclear disruption of a dense white dwarf star [6]. At the same silica is poorly documented but could be crucial in nutrient-limited time, 50Ti and 54Cr, but not 48Ca, have substantial production in massive soils where highly soluble primary silicates have been exhausted. A stars (e.g., [7]). It is likely that the dust in the interstellar medium is highly pot experiment using Durum wheat was conducted to assess the anomalous. When this dust is incorporated into the Solar cloud, the Solar capacity of different silicate sources to release bioavailable silicon. System will inherit these anomalies, and processing within the For this purpose we used three types of sources: quartz (Q), clay (C, vermiculite) and amorphous silica (D, diatomite, as an analogue for protoplanetary disk incorporates those anomalies in the FUN CAIs. In phytoliths). Mixtures (Q + C and Q + D) were prepared in different order to understand all of this history, we are making estimates of the proportions. Wheat plants were grown for 60 days in these mixtures. siting of these isotopes in the interstellar dust along with their expected We found that the plants grown in the Q + D mixtures accumulated isotopic anomalies. in their shoots about twice more silica (16-22 g kg-1) than those -1 grown in the Q + C mixtures (7-13 g kg ). These results show that, Tools for Understanding Nucleosynthesis and Galactic although soil amorphous silica (phytoliths) constitutes the most Chemical Evolution bioavailable Si pool for plants, the contribution of clay minerals Nucleosynthesis and chemical evolution are complex subjects that should be more fully evaluated. researchers best understand by running their own calculations. All of the

computational tools we are developing to understand chemical memory in Solar System samples are open source and available for download (e.g., [8]), and we hope these tools will help others gain a better appreciation for nucleosynthesis and Solar System isotopic anomalies.

[1] Clayton (1978) Moon and Planets 19, 109-137. [2] Lee, Papanastassiou, & Wasserburg (1978) Astrophys. J. Lett. 220, L21-L25. [3] Niederer, Papanastassiou, & Wasserburg (1980) Astrophys. J. Lett. 240, L73-L77. [4] Qin, Carlson, & Alexander (2011) Geochim. Cosmochim. Acta 75, 7806-7828. [5] Meyer, Krishnan, & Clayton (1996) Astrophys. J. 462, 825-838. [6] Woosley (1997) Astrophys. J. 476, 801-810. [7] Meyer , The, & El Eid (1996) Lunar and Planet. Sci. 27, 875. [8] http:// sourceforge.net/projects/nucnet-tools/.

Mineralogical Magazine | www.minersoc.org 2103 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Fractionation of highly siderophile Control of copper enrichment in Lau elements in the lower oceanic crust at Basin magmas by sulfide segregation ODP Site 735b, SW Indian Ridge and sulfur degassing 1 1 1* 2 3 4 C. MEYER *, H. BECKER P.J. MICHAEL , A. BÉZOS , C. LANGMUIR , S. ESCRIG 1Freie Universität Berlin, Institut für Geologische Wissenschaften, 1Dept. Geosciences, University of Tulsa, Tulsa, OK USA 74104 [email protected] [email protected] (* presenting author) 2Lab. Planet et Geodynamique, Univ. de Nantes, Nantes, France, Compared to the mantle, abundances of some HSE in gabbroic [email protected] oceanic crust and ocean ridge basalts are lower by a factor of 1000 3Dept. Earth & Planet Sci, Harvard Univ, Cambridge, MA, USA or more, with Re, Au and Pd being more abundant than Os, Ir, Ru, or 02138 [email protected] Rh. It has been suggested that the highly variable abundances may 4École Polytech. Féd. Lausanne, Lausanne, CH-1015, Switzerland reflect sulfide fractionation processes in the deeper oceanic crust [email protected] [1]. Samples from ODP site 735b, legs 118 and 176, a 1500 section of tectonically exhumed middle to lower oceanic crust were Lau Basin magmas show how magma ascent, crystallization and analyzed for abundances of HSE and Os isotopic composition. For degassing can lead to either enrichment or depletion of Cu (and reconnaissance study, 30 samples characterized by little alteration other chalcophile elements) in differentiated magmas. In these

were selected to cover a range of lithologies, including olivine magmas, S degassing is correlated with H2O degassing. Dissolved S gabbro, gabbro, troctolitic gabbro, troctolite and disseminated oxide occurs almost entirely as sulfide (S2-) in analyzed glasses. gabbro and oxide gabbro. 2.5 g of powder was digested in inverse Glasses from the northern part of Eastern Lau Spreading Center aqua regia in a high pressure asher at 320°C. HSE separation and (ELSC), located in the backarc, far from the active Tofua arc, are

analyses methods follow those established in our lab. In a Re-Os similar to MORB. They have not degassed H2O, and their dissolved S isochron diagram, the most radiogenic samples (with large errors) contents are high and correlated with Fe. They have not degassed plot along a 11 Ma reference line, in good agreement to the crustal much S but have segregated immiscible sulfide liquids which leads age of site 735b [2]. Two troctolitic gabbros and 3 olivine gabbros to a MORB-like trend of decreasing Cu with decreasing MgO. with 187Os/188Os of 0.14 - 0.24 display a different linear trend that Further south, ELSC (and its continuation, Valu Fa Ridge:VFR) is yields an apparent age of 244 ± 77 Ma with an initial 187Os/188Os of shallower and only 35-60 km from Tofua arc. Its magmas include a

0.126 ± 0.022. CI-chondrite normalized abundances of HSE in the greater subduction component, especially H2O which has degassed. lower crustal rocks cover a wide range (at the most extreme 10-3 to Low S contents show that they have also degassed variable amounts 10-7 x CI chondrite for Os), with relatively high abundances of all of S. Cu contents are slightly elevated compared to northern ELSC HSE in some troctolitic gabbros to more fractionated HSE patterns and MORB, and Cu decreases with decreasing MgO. and much lower abundances of Os, Ir, Ru, Rh and Pt in other In contrast, the small seamounts located a few km from the lithologies. Re is the least variable, with typical abundances in ELSC-VFR axis have Cu contents that increase with decreasing gabbros of 0.2 – 0.5 ppb, considerably lower than in most MORB. MgO, and reach much higher values than ELSC-VFR. They have

Au concentrations in most analyzed samples are typically <0.1 ppb. degassed large amounts of H2O and almost all of their Sulfur. Most Au is more strongly depleted than Re compared to MORB [3] and seamounts are more primitive than the nearby spreading axis. A few most mantle rocks. This would imply that Au is more incompatible analyzed glasses from the nearby Tofua volcanic arc are similar to than Re during fractional crystallization, at least in this section of the seamounts in their behavior of S and Cu. oceanic crust. From HSE abundance and ratio data, it appears that We propose that Cu contents in differentiated magmas are olivine gabbros behave as a coherent group, whereas troctolitic controlled by immiscible sulfide liquid segregation and S degassing. gabbros may reflect other processes. HSE abundances, Au/Ir, Pd/Ir Like MORB, glasses from northern ELSC undergo sulfide and Os/Ir in “primitive” olivine gabbros reach values >100 and segregation that depletes Cu from residual liquids, while very little S decrease substantially with decreasing Mg#, Cr, Ni and MgO. The is lost by degassing. Magmas from southern ELSC and VFR start progressive depletion of HSE in olivine gabbros may be related to crystallizing at moderate depths (6-8 km) where they segregate fractional crystallization from progressively evolved basic melts. some sulfide liquid, and lose Cu. They also undergo degassing of

This process appears to result in a strong increase in Re/Os from H2O and S as they crystallize and ascend to shallower levels, limiting olivine gabbro via gabbro to leuco gabbro and in a decrease of Au/Ir, the amount of formation of sulfide liquids and its consequent Cu Pd/Ir and Os/Ir. Consequently, while Re/Os in melts increase during depletion. In contrast, seamount (and arc) magmas ascend rapidly to

fractional crystallization, Au/Ir, Pd/Ir and Os/Ir decrease. The shallow levels and degas H2O and S before they have a chance to evolution of troctolitic gabbros, increasing Au/Ir and Pd/Ir with segregate immiscible sulfide liquid. Cu remains in the silicate liquid decreasing Mg# and Cr, follows different trajectories and implies and its concentration increases in differentiated magmas. more complicated processes, presumably, hybridization of An alternative mechanism to account for high Cu in some ultramafic cumulates or mantle tectonites by basic melts.. magmas is that during larger extents of partial melting beneath the

arc and seamounts (caused by high H2O in the source), sulfide in the [1] Hertogen et al. (1980) GCA 44, 2125 – 2143. mantle source is exhausted, releasing all Cu into the melt. However, [2] Dick et al. (1991) Proceedings of the ODP, Scientific Results low Cu in primitive seamounts suggests elevated Cu results from 118, 439 – 538. differentiation, not melting. [3] Keays and Scott (1976) Economic Geology 71, 705 – 718.

Mineralogical Magazine | www.minersoc.org 2104 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Potentially hazardous trace elements Synchysite: Implications for Titanite in biomass burned in power plants Destabilisation and Differential REE, 1 2 MAREK MICHALIK , RENATA GASEK , Y and Th Mobility in the Soultz 2 WANDA WILCZYŃSKA-MICHALIK Monzogranite 1 Institute of Geological Sciences, Jagiellonian University, 1* 2 1 A. W. MIDDLETON , H.-J. FÖRSTER , I. T. UYSAL AND S. D. Kraków, Poland, [email protected] (* presenting 1 GOLDING author) 2 Institute of Geography, Pedagogical University, Kraków, Poland, 1University of Queensland, Queensland 4072, Australia [email protected], [email protected] (*correspondence: [email protected]) 2GeoForschungsZentrum, Potsdam, Germany The study is based on eight samples of biomass (OTR- corn bran; SLON-1 and SLON-2 – sunflower; TRO – sawdust; OLI – olive High heat-producing granitic rocks (HHPGs) are characterised residue; SLOM - straw; BUK – beech bark; PAL – palm kernels) by abnormally enriched values of radiogenic U, Th and K above used in power plants in southern Poland and ashes obtained in upper continental crustal averages. In recent years, HHPGs have relatively low temperature (475oC). Results are compared with received considerable attention as they can be targeted for enhanced average trace element contents in coal and coal ash [1]. geothermal systems (EGS). The Soultz-sous-Forêts monzogranite is Fourteen elements were selected as components of major a notable example. With the exception of K, U and Th commonly environmental concern (As, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, occur with rare earth elements and yttrium (REE and Y, REY) in Se, V, Zn). Average values for hard coal are exceeded in biomass primary accessory phases [1]. Upon interaction with hydrothermal only for four elements (Table 1). The concentration of trace fluids, accessory phases such as titanite, may destabilise and form elements in biomass ash can be very high and for eight elements polyminerallic metasomatic assemblages. Analysis of these significantly exceed average values determined for coal ash (Table metasomatic minerals is integral for understanding not only the 2). The results indicate that concentration of several trace elements chemistry of the hydrothermal fluid, but also the mobility of in biomass used as fuel and in biomass ash could be dangerous for elements previously held in primary accessory phases. As such, this environment. study focuses on the comparative EPMA of primary and metasomatic accessory phases to further the understanding of REE, Element Average for Highest values for studied Y and Th mobility in the Soultz monzogranite. hard coal biomass samples Petrographic studies show primary REY and Th-bearing titanites Cd 0.2 0.31(TRO) have been altered to anatase + calcite + quartz + synchysite-(Ce) Cu 16 25 (OLI); 23 (PAL) [(Ce,Ca,Th)(CO3)2F] ± bastnaesite-(Ce) [(Ce,Th)(CO3)F] or Mn 71 333 (PAL); 126 (OTR); 88 (BUK) monazite-(Ce) [(Ce,Th)PO4] + xenotime-(Y) [(Y)PO4] ± thorite Zn 28 79 (OTR); 46 (PAL) [ThSiO4]. These observations represent the first documented citing Tabl e 1. Highest values of trace elements in biomass samples of synchysite-(Ce) formation through titanite destabilisation. The exceeding average value for hard coal (in ppm) purely fluorocarbonate-bearing assemblage is restricted to samples exhibiting minor selective alteration. Phosphate-bearing Element Average for Highest values for studied assemblages are, however, found in pervasively altered samples coal ash biomass ash samples where primary apatite was significantly affected. Comparative mass Ag 590 5319 (TRO) balance studies of titanite, synchysite-(Ce) and monazite-(Ce) found HREE O , Y O and ThO levels to be relatively depleted in Cd 1.2 71 (TRO); 2.1 (OTR); 1.66 (SLON-2) 2 3 2 3 2 fluorocarbonate-bearing samples. Although ThO levels were Cu 110 587 (TRO); 509 (PAL); 266 (SLON-2); 2 maintained in monazite-(Ce) relative to parent titanite, HREE O and 255 (SLON-1); 178 (OTR); 169 (OLI) 2 3 Y O appeared lower due to the presence of xenotime. Mn 430 >10 000 (TRO); 7373 (PAL); 2148 2 3 Following the experimental work of Hunt and Kerrick [2], the (OTR); 1507 (BUK); 444 (SLOM) ingress of CO -rich fluid was integral for titanite destabilisation. On Mo 14 14.7 (OTR) 2 the other hand, fluorine in synchysite was most likely sourced from Ni 37 49 (PAL); 38 (OLI) proximal chloritised biotite. Following synchysite formation, excess Pb 55 69 (TRO) - - FCO3 or HCO3 anions may have remained in solution and led to the Zn 170 1923 (TRO); 1485 (OTR); 1051 (PAL); significant mobilisation of HREE, Y and Th through complexation. 428 (BUK); 399 (SLON-2); Our study provides evidence for not only differential REE and Y 321(SLON-1) mobility in the Soultz monzogranite, but also that Th, conventionally Tabl e 2. Highest values of trace elements in biomass ash samples considered an immobile element, is mobilised under certain exceeding average value for hard coal ash (in ppm) hydrothermal conditions. [1] Ketris & Yudovich (2009) International Journal of Coal [1] Bea (1996) J Petrol 37, 521-552. [2] Hunt & Kerrick Geology 78, 135-148. (1977) Geochim Cosmochim Ac 41, 279-288 Study was supported by NCN grant No. 0579/B/P01/2011/40.

Mineralogical Magazine | www.minersoc.org 2105 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Modelling the vapour transport of The role of changing abstraction Au, Ag, and Cu chlorides at high patterns in the contamination of a temperature based on new low-arsenic aquifer in Bangladesh

experimental data I. MIHAJLOV1*, M. STUTE1,2, B.C. BOSTICK1, I. CHOUDHURY3, 3 1 1* 1 K.M. AHMED AND A. VAN GEEN ART. A. MIGDISOV , N. HURTIG , AND A.E. WILLIAMS- 1 JONES 1Lamont-Doherty Earth Observatory of Columbia University, 1McGill University, Earth & Planet. Sci., Montreal, QC, Palisades, NY, USA, [email protected] (* presenting Canada (*correspondence: [email protected]) author) 2 Barnard College, New York, USA 3 The fact that water can significantly increase the gaseous Dhaka University, Dhaka, Bangladesh transport of weakly volatile compounds has been long-known and is attributed to hydration, namely the formation of gaseous clusters The installation of deeper aquifer community wells has been one of the primary arsenic mitigation strategies in Bangladesh, a country involving H2O molecules. However, laboratory experiments where a large portion of shallow tubewell groundwaters exceed the performed in simple H2O-bearing systems have yielded concentrations of metals, e.g., Cu and Au, considerably lower than WHO limit of 10 µg/L As. Shifting groundwater abstraction patterns, reported for vapour inclusions in many natural samples. in particular the increased pumping from deeper aquifers, could Furthermore, calculations of the stability of known Cu- and Au- potentially threaten this resource by vertical transport of As and bearing gaseous clusters have shown that these clusters cannot organics between aquifers and across leaky confining units. While explain the very high concentrations Cu and Au predicted for some this scenario has been addressed by Bengal basin-wide models [1], vapour-dominated hydrothermal systems. Assuming that the source hydrogeologic conditions across the basin are variable. of this disagreement lies in the models that have been developed for Our study focused on a site 25 km east of Dhaka where a community well was installed twice in a low-As aquifer separated the hydration process, we have re-visited the Au-HCl-H2O, AgCl- from the shallow aquifer by >10m of silty clay, but As levels in both HCl-H2O, CuCl-HCl-H2O, and CuCl2-HCl-H2O systems, and conducted additional experiments that allow us to more accurately wells rose within <18 months. An increasing downward hydraulic determine the hydration numbers of metal-bearing gas clusters. gradient across clay units in the vicinity, as well as a lack of evidence Our experiments involved determining the solubility of metal of mechanical failures at the site, led us to suspect vertical leakage chlorides (or metals) in HCl-bearing water vapour at a variety of across the clay. Thus, a network of pumping and monitoring wells water vapour pressures and temperatures ranging from 300 to 450 was established on the site to conduct pumping tests and continuously °C. The experimental technique employed in this study is identical monitor hydraulic heads. Lithologs, sediment X-ray fluorescence to that reported in our previous publications [1]. The data obtained (XRF) and chemical extraction profiles were collected during well from these experiments demonstrate that, in contrast to conclusions installation, and groundwater was sampled for water chemistry, DIC 13C and 14C, 2H, 18O, 3H, and noble gas analysis. in our earlier publications, hydration numbers of metal-bearing Lithologs and XRF profiles established that stratigraphy and clusters are not constant, but increase with increasing fugacity of sediment composition were laterally uniform. Pumping from long- water. This results in an exponential increase in the saturation screen wells in either aquifer did not induce measurable drawdown in concentrations of metals in water wapour at elevated pressures and the other, but the time plot of drawdown in the confined aquifer was temperatures. characteristic of a leaky aquifer. Given the present downward We fitted our experimental data to a simplified model similar to hydraulic gradient of ~1m between the aquifers, continuous slow that developed by Pitzer and Pabalan [2] for the solubility of NaCl in downward transport of As and/or organics across the clay may exist. low-density fluids. The model accounts for a set of hydrated species High-As groundwater is absent at the depth of the community of the common stoichiometry MeCl(H2O)n, where n ranges from 1 well failures, but the upper ~10m of the aquifer (below the clay) is to 14. After independent treatment of each of the experimental 3H-dead and displayed high dissolved conc. of Fe, As, and NH . The isotherms, it was found that the Gibbs free energy of each of the 3 well-advanced reduction in this stratum was accompanied by elevated modelled clusters varies linearly with the reciprocal absolute Na, DOC, and DIC levels, and a lower pH. Depressed 14C and heavy temperature (1/TK). This allows extrapolation of the data collected 13C signature of the DIC there, along with low diss. [Ca], was at 300 to 450 °C to much higher temperatures. The new model has characteristic of microbial consumption of old organic C (potentially been tested against the measurements of Simon et al. [3] for the leached from the clay with Na) and methanogenesis. Water level and solubility of Au and Ag at 1000 to 1400 bar and 800° and yield 3H data, however, also implied that a flow of recently recharged reasonable results. .In addition, the concentrations of Ag and Au (the water exists below this upper portion of the aquifer, presumably due experiments on Cu are still in progress) calculated for 500 °C show to pumping from a nearby factory. While the community wells much closer approximation to those determined in natural fluid probably failed due to vertical transport of As within the aquifer inclusions than in any previous models itself, it is presently unclear if the source of As and DOC in the upper

[1] Archibald et al. (2001) Geochim. Cosmochim. Acta, 65, 4413 part of the aquifer is from clay leakage or if that layer is a zone of [2] Pitzer and Pabalan (1986) Geochim. Cosmochim. Acta, 50, low flow where resident organic C is currently consumed. 1445 [3] Simon et al. (2005) Geochim. Cosmochim. Acta, 69, 3321 [1] Radloff et al. (2011) Nature Geoscience 4, 793-798.

Mineralogical Magazine | www.minersoc.org 2106 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Late Miocene Central Anatolian Evidence for distinct stages of magma surface uplift and orographic rainout evolution recorded in the composition from stable hydrogen and oxygen isotope records of accessory phases and whole-rocks 1,2 1,2 2 TAMÁS MIKES *, ANDREAS MULCH , FABIAN SCHEMMEL , 3 4 5 DOMENICO COSENTINO , BORA ROJAY AND ERKAN AYDAR in silicic magmas 1* 1 2 1 Goethe University, Institute of Geosciences, Frankfurt am Main, ANDREW MILES , COLIN GRAHAM , MARTIN GILLESPIE , 3 1 4 Germany, [email protected] (* presenting author) CHRIS HAWKESWORTH , RICHARD HINTON AND EIMF 2 Biodiversity and Climate Research Centre (BiK-F), Frankfurt am 1 Grant Institute of GeoSciecnes, University of Edinburgh, Main, Germany, [email protected]; Edinburgh, UK, [email protected] (* presenting author) [email protected] 2 3 British Geological Survey, Edinburgh, UK, [email protected] Department of Geosciences, University Roma Tre, Rome, Italy, 3 School of Geography and Geoscicences, University of St Andrews, [email protected] 4 St Andrews, UK, [email protected] Middle East Technical University, Institute of Geological 4 Edinburgh Ion Microprobe Facility, University of Edinburgh, Engineering, Ankara, Turkey, [email protected] Edinburgh, UK, [email protected] 5 Hacettepe University, Department of Geological Engineering,

[email protected] Accessory minerals may contain a detailed record of the evolution

of silicic magmas. Different stages of magma evolution are A stable isotopic aproach to surface uplift history of the S preserved in the trace element compositions of apatite inclusions margin of the Central Anatolian Plateau (CAP), the second largest and their host rocks in the normally zoned Criffell pluton, southern orogenic plateau in the Alpine-Himalayan belt, is the focus of this Scotland. Apatites in metaluminous outer zones define a trend of work. Extending at average elevations of 1 km and bordered by the 2- variable La (277 to 2677 ppm) and less variable Y (0 to 662 ppm) 3 km-high Tauride Mts to the S, Mediterranean mantle dynamics (trend 1), and lie on the same trend as that defined by the whole- have been instrumental in governing regional surface uplift [1], yet rocks (WR) throughout the pluton. By contrast, apatites from with detailed temporal and spatial patterns of surface uplift peraluminous inner zones show variable Y (276 to 2677 ppm) and remaining conjectural. For the first time, we apply a paleoaltimetric low La (<1079 ppm) (trend 2). WR isotopic and elemental trends approach to the CAP by (1) looking at stable hydrogen and oxygen have previously been modelled by assimilation and fractional isotope ratios of continental deposits (such as paleosol and 18 crystallization (AFC) [1]. Zircon δ O varies by more than 3‰ lacustrine carbonates and hydrated volcanic glasses), taking between zones, but zircons within individual zones (within which advantage of their recent, precise age calibration based on chrono- apatite is included) are mostly within analytical error (0.4‰ 2σ) and and biostratigraphy, and (2) providing a robust template of stable thus show limited evidence for assimilation during crystallization of hydrogen and oxygen isotopes from modern surface waters on the apatite and zircon. Crucially, in each metaluminous zone only the CAP and across the Tauride Mts, against which the continental proxy most primitive (La-rich) apatites crystallized from melts that data can be validated. We show that integrity of the modern meteoric closely match its WR composition. Both the WR and the most water data nicely images the present-day topographic structure of primitive apatites in each metaluminous zone therefore preserve the CAP and the Tauride Mts. with ca. -24 ‰/km and -3 ‰/km liquidus compositions, and little open system fractionation occurred isotopic lapse rates for δD and δ18O, respectively. We then compare throughout the crystallization of accessory phases in these zones. two sets of δ18O data of fossil meteoric waters as recorded in proxy Trend 2 reflects the effects of monazite crystallization in minerals from Upper Miocene to Quaternary deposits in front of the peraluminous zones that led to depletion of La in accessory phases growing Tauride Mts and in its N rainshadow. The data reveal fairly that crystallized after monazite saturation. However, no WR uniform isoscapes at the S plateau margin until 6.3 Ma, with a major compositions lie on trend 2, indicating that they were not influenced isotopic shift occurring between 8.2 and 5.5 Ma, with a by monazite fractionation. Variations in apatite trace element Δ(δ18O ) of 3.4 to 5.6 ‰. This difference corresponds to win dward-leeward concentrations within each zone therefore reflect the effects of in ca. 50 to 75% of that of the present-day altitude effect on isotope situ crystallization of allanite in metaluminous zones and monazite fractionation across the Taurides. Combined with stratigraphic in peraluminous zones. The independently determined compositions evidence from margin-capping shallow-marine deposits of 8.4 to 8.1 of WR and apatites support numerical models for the existence of Ma age [1], and with basin subsidence history at the Tauride front crustal hot zones in the formation of silicic magmas [2]. WR revealing a major clastic influx at 5.5 Ma [2], we conclude that 1000 compositions are determined at depth while textural maturity and the to 1500 m of surface uplift occurred in less than 2.7 Ma, pointing to compositions of accessory minerals such as apatite and zircon are notably high uplift rates of 0.4 to 0.6 mm/yr for the Taurides in the largely determined at shallower depths by the presence or absence Tortonian to Messinian. Our data compare well to short-term of other accessory phases during in situ crystallization of small melt Quaternary uplift rates on incised river terraces [3]. batches.

[1] Cosentino et al. (2012) GSA Bull. 124, 133-145. [1] Stephens et al (1985) Contributions to Mineralogy and Petrology [2] Cipollari et al. (accepted) GSL, Spec Publ. 89, 226-238. [3] Schildgen et al. (2012) EPSL 317-318, 85-95. [2] Annen et al (2006) Journal of Petrology 47, 505-539.

Mineralogical Magazine | www.minersoc.org 2107 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Picrite-driven cratonization: a Li and B isotopic composition of perspective from the NeoArchean basement rocks, Dawn Lake area, Ungava craton Athabasca Basin, Saskatchewan

1 1 DEJAN MILIDRAGOVIC *, DON FRANCIS , AND DOMINIQUE ROBERT MILLAR1,3*, IRVINE R. ANNESLEY2,3, ROBERTA L. 2 WEIS RUDNICK4, XIAOMING LIU4 , AND KEVIN ANSDELL3 1McGill University, Earth and Planetary Sciences, Montreal QC 1Saskatchewan Research Council, Saskatoon, Canada, [email protected] (*presenting author) [email protected] (* presenting author) [email protected] 2JNR Resources, Saskatoon, Canada, [email protected] 2Univ. British Columbia, EOS, PCIGR, Vancouver BC 3University of Saskatchewan, Saskatoon, Canada, [email protected] [email protected] 4University of Maryland, College Park, United States of America, Zoned ultramafic/mafic plutonic rocks emplaced at mid-crustal [email protected], [email protected] depths occur scattered across the disparate terranes of the Ungava craton of the Archean Superior Province. These Qullinaaraaluk (Q- Recent literature suggests Li isotopic fractionation can occur suite) intrusions are coeval with the ca. 2.74-2.72 Ga pyroxene- during weathering, hydrothermal alteration, igneous and bearing granitoids and high-K granitoids that dominate the Ungava metamorphic processes [1], while the B isotopic signature preserved craton [1], and their wide spread distribution suggests that mantle- derived magma may have played a key role in cratonization of the in refractory minerals, such as tourmaline, can aid in determining the northern Superior province at the end of Archean. The Q-suite source of fluids and P-T conditions during crystallization [2]. The 7 intrusions are small, irregularly-zoned cumulate bodies that include objectives of this research are to determine the G Li and G% of a spectrum of lithologies, ranging from olivine-dominated relatively fresh to strongly altered basement lithologies in the vicinity adcumulate-mesocumulate cores to more evolved gabbro(norites). of uranium mineralization in the Athabasca Basin (SK, Canada) and Their parental magmas appear to have been H2O-rich as indicated by to evaluate if bulk isotopic analysis of Li and B can provide insight the abundance of oikocrystic amphibole in the mesocumulate rocks. into the fluids that precipitated this mineralization with implications Electron microprobe analyses of olivine (Fomax = 85) from peridotitic cores across the peninsula, suggest that the parental as a possible vectoring tool. magmas were enriched in Fe relative to present day picritic magmas. The largest high grade uranium deposits in the world are found Although the Q-suite intrusions intrude a number of isotopically within the Athabasca Basin of northern Saskatchewan, although the distinct terranes (Boily et al. 2009), their trace element signatures source of the uranium and the ultimate depositional mechanism are + are strikingly similar across the entire 300 km width of the Ungava still highly debated. A suite of samples from the Dawn Lake area Craton. Despite the Fe-rich composition of their parental magmas, (12.9 M lbs @ 1.69% U O ) include fresh to strongly altered Q-suite rocks are characterized by “calc-alkaline” trace element 3 8 graphitic pelitic gneiss and granitic pegmatites. Li concentrations signatures, with relatively flat (MREE/HREE)PM, elevated from bulk chemical analysis range between 76 and 369 ppm, whereas (LREE/MREE)PM, and strong depletions in the HFSE, in particular Nb and Ta (Fig. 1). Furthermore, the pyroxene-bearing granitoids B concentrations vary between 62 and 915 ppm. The elevated have compositions that span the gap between the coeval Q-suite and concentrations of Li and B are related to the presence of high-K grantoids, indicating intimate interaction between mantle- hydrothermal clay minerals and tourmaline, while the latter is also derived magmas and crustal melts. Geochemical, mineralogical and present as earlier formed magmatic and/or metamorphic minerals. field data thus suggest that the craton-wide emplacement of Fe-rich The significant concentrations of Li and B were more then adequate picritic magma with “calc-alkaline” trace element affinities may for isotopic analysis, G7Li measured by MC-ICP-MS relative to L- have been responsible for the crustal melting episode that stabilized the Ungava craton at the end of the Archean. SVEC display values between +4‰ and +13‰ for pelitic and graphitic pelitic gneiss and +6.2 to +18.6‰ for granitic pegmatites. The G% measured by HR-ICP-MS relative to NBS951 was determined for granitic pegmatites to be in the range from -5.3 to 1.6 ‰, whereas the G% for metasediments range from -0.8 to 3.5 ‰. There is no correlation between the elemental concentration of Li and B and the isotopic composition, but large variations in G7Li and G% may be due to mixing of magmatic/metamorphic and hydrothermal components (eg., [3]) in these bulk samples. Further work will aim to unravel the cause of the isotopic variability and determine whether G7Li and G% of bulk samples can aid in vectoring towards U mineralization.

[1] Teng et al. (2006) American Mineralogist 91, 1488-1498.[2] van Hinsberg, Henry and Marschall (2011) The Canadian Mineralogist Figure 1: Primitive mantle-normalized trace element abundances in 49, 1-16. [3] Mercadier, Richard and Cathelineau, (2012) Geology, representative Q-suite websterites and wehrlites doi: 10.1130/G32509.1

[1] Maurice et al. (2009) Prec Res 168, 45-65. [2] Boily et al. (2009) Prec Res 168, 23-44.

Mineralogical Magazine | www.minersoc.org 2108 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Iodide and iodate interactions with Peach Spring Tuff, Arizona- clay minerals California-Nevada, USA: Generating 1* 1 1 ANDREW MILLER , JESSICA KRUICHAK , HERNESTO TELLEZ , an isolated supereruption 1 YIFENG WANG 1* 1 2 C.F. MILLER , A.S. PAMUKCU , C.A. FERGUSON, , T.L. 1 1 3 1Sandia National Laboratories, Albuquerque, USA, CARLEY , G.A.R. GUALDA , J.L. WOODEN , W.C. 4 5 5 [email protected] (* presenting author) MCINTOSH , M. LIDZBARSKI , J.S. MILLER , AND S.M. 1 MCDOWELL

1 Abstract Vanderbilt Univ, Earth & Env Sciences, Nashville USA, [email protected] (* presenting author) Clay minerals are likely candidates to aid in waste isolation due 2Arizona Geological Survey, Tucson USA, [email protected] to their low permeability, favorable swelling properties, and high 3Stanford U, Geol & Env Sci, Stanford USA, [email protected] cation sorption capacities. Iodine-129 is often the major driver of 4NM Tech, Earth & Env Sci, Socorro USA [email protected] exposure risk from nuclear waste repositories at timescales 5San Jose State Univ, Geology, [email protected] >10,000 years. Therefore, understanding the geochemical cycling of

iodine in clays is critical in developing defensible quantitative The >700 km3 Peach Spring Tuff (PST) is exposed through descriptions of nuclear waste disposal. much of the western Colorado Plateau and the extended terrane of Anions are not typically considered to interact with most clays southern Nevada, SE California, and NW Arizona. Voluminous early as it is assumed that the fixed negative charge of clays actively volcanism and plutonism characterized the early Miocene history of repels the dissoloved anion. This is corroborated by many batch this region, but large ignimbrites were rare and PST was almost an studies, but diffusion experiments in compacted clays have shown order of magnitude larger than any other erupted deposit. iodide retardation relative to chloride. The reasons for this are Discovery of the source of PST (Silver Creek caldera, southern unknown; however, several possible hypotheses include: redox Black Mtns, AZ [Ferguson 2008]), a refined 40Ar/ 39Ar sanidine age transformation controls on sorption behavior, complex surface (18.78±0.02 Ma, intracaldera & outflow [Ferguson et al in rev]), and charge environments due to overlapping charge domains, and detailed studies of pumice [Pamukcu et al in revision] shed light on sorption to ancillary minerals or weathering products. the eruption and magma chamber evolution that preceded it. A series of clay minerals have been examined using several Phenocryst assemblages are consistently san>plag+bio+ techniques to chracterize the surface charge environment of the hbl>qtz+px, +prominent sphene+zrc+all/chev. However, clays, as well as to discern the potential for redox transformation intracaldera pumice is distinct from distal outflow: richer in and variable sorption behavior of different iodine oxidation states. phenocrysts (~30-40%, showing strong resorption textures, vs Surface charge environments were examined through surface <10%, mostly euhedral), trachyte rather than rhyolite (66-69 wt% titrations and cation exchange capacity determination with SiO2 vs 74-76 wt%). Thick proximal sections have common high-Si methylene blue. Batch sorption experiments were completed with pumice, but in their upper parts crystal-rich, low-Si rhyolite-trachyte illite and palygorskite samples with both iodide and iodate. The batch pumice is present. Core-rim zoning in zrc and sph in lower-Si experiments were completed at a range of pH values from 4-10, and pumice have compositions suggesting late growth from hotter less at a constant ionic strength of 0.1M NaCl. Sorption experiments evolved melt (e.g. zrc rims to 50 ppm Ti: T >~900 C), in contrast to were performed at 20g/L solid:solution ratios to exacerbate normally-zoned counterparts in high-Si pumice. Crystal size sorption properties. The results show a range of sorption behaviors distributions and resorption textures also point to late heating in based on the clay mineral involved, as well as chemical conditions low-Si but not high-Si pumice. such as pH. Palygorskite has a higher sorption affinity for iodide We propose that trachyte in the caldera and proximal outflow compared to illite. There is evidence for some anion exhchange represents basal cumulate mush within a zoned magma body, and that capacity on palygorskite; iodide sorption led to fluoride release. Si-rich outflow pumice was derived from higher levels. Only the While not typically considered as a disposal medium, this result lower portion was affected intensely by a pre-eruption heating event. points to the use of alternative clay minerals to further isolate Rhyolite-MELTS simulations suggest that the trachyte was melt- anionic components in nuclear waste. poor and ineruptible prior to reheating. The most plausible Sandia National Laboratories is a multi-program laboratory mechanism for heating and destabilizing of the mush, and perhaps managed and operated by Sandia Corporation, a wholly owned for triggering eruption as well, is basal injection of hot, more mafic subsidiary of Lockheed Martin Corperation, for the U.S. Department magma. Mafic injection is consistent with presence of sparse of Energy’s Nation Nuclear Security Administration under contract andesite magmatic enclaves within the ignimbrite and of a near- DE-AC04-94AL85000. caldera basaltic andesite lava that was was emplaced just prior to the

PST supereruption.

Regional uniqueness of the PST poses a conundrum: either

super-quantities of eruptible magma or triggers to destabilize them must have been generally lacking, yet regional magma flux was high and interaction between felsic and mafic magma was ubiquitous.

Mineralogical Magazine | www.minersoc.org 2109 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Identification of the geographical Magma dynamics beneath the origin of exotic wood species using ancient Mt. Etna: Clinopyroxene 87Sr/86Sr isotope amount ratios isotopic and thermobarometric

1* 2 1 KERRI MILLER , TYLER COPLEN , AND MICHAEL WIESER constraints

1 Department of Physics and Astronomy, University of Calgary, 2500 S.A. MILLER1*, M. MYERS1, J.G. BRYCE1, J. BLICHERT-TOFT2 University Drive NW, Calgary, AB, T2N 1N4, Canada, 1University of New Hampshire Earth Sciences, Durham, NH USA [email protected] (*presenting author) (*[email protected], correspondance) 2US Geological Survey, 12201 Sunrise Valley Drive, Reston, VA, 2Ecole Normale Supérieure de Lyon, Lyon, France 20192, USA

Early stages of volcanism associated with Mount Etna, Europe’s Rosewood species constitute only a small amount of the largest and most active volcano, began at ~0.5 Ma [1] and are now Dalbergia genus, however this wood is highly sought after for use in preserved around the perimeter of the modern-day edifice [2]. expensive cabinetry, flooring, musical instruments, and decorative Magmatic products of these early centers, including those of ancient objects. As a result, rosewood is an over-exploited resource and alkali centers active between ~200 and ~100 ka, generally have three species of the Dalbergia genus are currently controlled by the mantle-derived isotopic signatures consistent with contributions from Convention on International Trade in Endangered Species of Wild both enriched and depleted source components. More recent Etna Flora and Fauna (CITES). Because some rosewood species are volcanics exhibit tell-tale signs of assimilation, but the degree to threatened with extinction, trade for commercial purpose is illegal. which this affected the early products is debated. Here we use an Despite the efforts of international trade officials to prevent illegal approach combining clinopyroxene (cpx) thermobarometry with an export of this wood species, it is still common to hear about new investigation of Pb, Hf and Nd mineral-whole rock isotopic investigations taking place. The goal of this study is to use (dis)equilibrium to constrain the depths at which magmas crystallized strontium isotopic composition to aid in the determination of the beneath these alkali centers and to gain insight into the nature of the geographical origin of wood samples in an effort to prevent the source of ancient Etna lava isotopic signatures. The advantage of illegal trade of exotic timber. using these three isotopic systems together lies in coupling two

slowly diffusing elements (Hf and Nd) with a more rapidly diffusing The 87Sr/86Sr isotope amount ratios in 120 wood samples were one (Pb), thereby providing the potential to infer any links between analyzed by thermal ionization mass spectrometery. Samples were the timing of magma mixing (or assimilation) and eruption [cf. 3]. identified by species and country of origin. Isotope amount ratios We have applied detailed single-cpx and cpx-liquid varied from 0.704174 to 0.790101 with external repeatabilities thermobarometric modeling based on back-calculated liquids from typically on the order of 20 ppm (2s). Many regions exhibited a whole rock compositions [4] and the models of Putirka [5]. Crystals distinct isotopic fingerprint. from two mafic flows from ancient alkali centers yield temperatures of 1140-1180 qC and 1090-1130 qC. Calculated initial crystallization depths lie at or below the Moho [6], consistent with polybaric fractionation and shoaling crystallization depths over time. Hf-Pb-Nd isotopic data from cpx phenocryst separates of ancient alkali lavas indicate no difference between whole rock and cpx values. Accordingly, we infer that the isotopic signatures of these magmas were locked in at pressures, at minimum, corresponding to early cpx crystallization. The lack of isotopic disequilibrium also suggests that the magmas were relatively well-mixed by the time they ascended to the depths at which cpx crystallization began. Taken together, our results support the interpretation that observed isotopic systematicatics in ancient Etna lavas result from mixing between MORB-like and enriched mantle sources, with volatile-bearing peridotite and pyroxenite components preferentially melting to generate ancient alkaline volcanism. Shallower crystallization depths recorded in some phenocrysts correspond to the current location of a high-velocity body in the upper crystalline basement [7], indicating that this may be a long-lived feature.

[1] Gillot et al. (1994) Acta Volcanol. 5, 81-87 [2] Tanguy et al. (1997) JVGR, 75, 221-250 [3] Bryce and DePaolo (2004), GCA 68, 4453-4468 [4] Armienti et al. (2007) GSA Sp. Paper, 418, 265-276 [5] Putirka, (2008) Rev. Mineral., 69, 61-120 [6] Nicolich et al. (2000) Tectonophys., 329, 121-139 [7] Patanè et al. (2003) Science, 299, 2061-2063.

Mineralogical Magazine | www.minersoc.org 2110 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Solubility of fish-produced high Ultra-high precision Fe isotope magnesium calcite analysis of eucrites and diogenites - Fe stable isotope fractionation during 1 1 FRANK J. MILLERO * AND RYAN WOOSLEY planetary differentiation? 1Rosenstiel School of Marine and Atmospheric Science,University 1,* 1 2 1 of Miami, Miami, FL 33149, USA, [email protected] M.-A. MILLET , J.A. BAKER , M. SCHILLER , J. CREECH , J. 1 2 (* presenting author) DALLAS , M. BIZZARRO

[email protected] 1Victoria University of Wellington, Wellington, New Zealand,

*[email protected] It has been suggested that the fish produced high 10 to 48% 2 Center for Star and Planet Formation, Natural History Museum of magnesium calcite can contribute to the input of calcite to the Denmark, University of Copenhagen, Denmark oceans. Fish produce this material as part of the physiological mechanisms for maintaining salt and water balance. In this paper, we The redox state of mantle sources, fractional crystallization of report on the first measurements of the solubility of this high minerals with varying Fe3+/Fe2+ ratios, diffusion processes and high magnesium calcite in seawater. The solubility (pK*sp = 5.89 ± 0.09) pressure silicate-metal segregation have been identified as the main of this material is approximately two times higher than aragonite causes of Fe stable isotope variations in terrestrial magmatic rocks (pK*sp = pK*sp = 6.18) and similar to the high magnesium calcite [1-4]. However, samples from smaller reduced planetary bodies generated on the Bahamas Banks (pK*sp = 5.90). The dissolution of show limited Fe stable isotope variations similar to chondritic this fish-produced CaCO3 input to the oceans will be discussed. The values, which may indicate that Fe isotopes are not fractionated by higher solubility of this fish-produced carbonate to surface ocean any other processes during planetary formation and differentiation waters may partially explain the increase in total alkalinity above the [1,5]. However, the limited number of samples measured and the aragonite saturation horizon in the oceans. More recent work has precision of the available data preclude this as a definitive shown that the production of this high-magnesium calcite may affect interpretation. the total alkalinity of coral reefs. Diogenites and eucrites originate from the HED parent body, thought to be the asteroid 4-Vesta, and may have been generated during the crystallization of a nearly complete magma ocean within a few millions years of Solar System formation [6]. As such, they offer a unique opportunity to investigate the fractionation of Fe stable isotopes during planetary formation and differentiation, provided suitable analytical precision can be attained. Here we present ultra-high precision Fe stable isotope measurements on a suite of diogenites and eucrites obtained by high-resolution MC-ICP-MS using a 57Fe-58Fe double spike to correct for instrumental mass bias (2 sd = 0.02‰, [7]) along with major and trace element concentrations and μ26Mg* values (for diogenites only, [6]). This dataset will allow us to investigate in detail the processes occuring during the development of planetary embryos and if Fe stable isotope fractionation occurred during differentiation of the HED parent body.

[1] Dauphas et al. (2009) EPSL 288, 255-267. [2] Liu et al. (2010) GCA 74, 6249-6262. [3] Teng et al. (2011) EPSL 308, 317-324. [4] Polyakov (2009) Nature 323, 912-914. [5] Weyer et al. (20050 EPSL 240, 251-264. [6] Schiller et al. (2011) ApJ lett 740, L22. [7] Millet et al. (2012) Chem. Geol. in press.

Mineralogical Magazine | www.minersoc.org 2111 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts U-Th-Pb geochronology of meta- Lithium isotopes systematics in carbonatites and meta-alkaline rocks Geothermal systems

1* 2 1 1* 2 LEO J. MILLONIG , AXEL GERDES , LEE A. GROAT ROMAIN MILLOT , PHILIPPE NÉGREL , AND BERNARD 3 1Department of Earth and Ocean Sciences, University of British SANJUAN Columbia, Vancouver, Canada, [email protected] (*presenting 1BRGM, Metrology Monitoring Analysis Department, Orléans, author), [email protected] France, [email protected] (* presenting author) 2Institut fuer Geowissenschaften, Goethe University Frankfurt, 2 BRGM, Metrology Monitoring Analysis Department, Orléans, Germany, [email protected] France, [email protected] 3 BRGM, Department of Geothermal Energy, Orléans, France, U-Pb and Th-Pb ages of zircons from eight meta-carbonatite and [email protected] four meta-alkaline rock samples provide evidence for three distinct episodes of carbonatite and alkaline magmatism in the southern Assessing the origin and behaviour of lithium and the Canadian Cordillera spanning a period of ~460 Ma. The earliest distribution of Li isotopes in geothermal systems is of major (Neoproterozoic) event occurred at ~800-700 Ma and coincides importance in order to increase our knowledge of the lithium with the postulated initial break-up of Rodinia. The second, cycling in the Earth’s crust. Lithium is a fluid-mobile element and previously undocumented, event of carbonatitic magmatism is constrained to the Late Cambrian to Early Ordovician at ~500-490 due to the large relative mass difference between its two stable Ma and corresponds to a period of extensional tectonics that isotopes, it is subject to significant low and high temperature mass affected the western continental margin of North America from the fractionation which provides key information on the nature of Canadian Cordillera to the southwestern United States. The youngest water/rock interaction processes. The main objective of the present and most prevalent period of alkaline igneous activity occurred in work is to constrain the behaviour of Li and its isotopes in Late Devonian to Early Carboniferous times at ~360-340 Ma and geothermal systems both for geothermal water samples representing also resulted from extensional tectonics. In addition, different episodes of amphibolites facies metamorphism subsequently deep circulation in the crust and by using an experimental approach. affected the igneous rocks between ~170-50 Ma. The magmatic emplacement ages, as well as the time of The behaviour of Li and its isotopes (G7Li) have been subsequent metamorphism, were further confirmed and constrained characterized in geothermal systems located in volcanic island arc by U-Th-Pb dating of the accessory minerals baddeleyite, titanite, areas: Guadeloupe, Martinique islands [1] and in New Zealand [2]. monazite, allanite, pyrochlore, and apatite (Figure 1). Moreover, one particularly important aspect of this work was to

establish the nature, extent and mechanism of Li isotope fractionation as a function of temperature during water/rock interaction. And, we also report results of Li isotope exchange experiments during seawater/basalt interaction (from 25 to 250°C). These results confirm that Li isotopic exchange is strongly temperature dependent, and demonstrate the importance of Li isotopic fractionation during the formation of Li-bearing secondary minerals and allow us to determine the following empirical relationship

between isotopic fractionation and temperature: ' solution – solid = 7847 / T – 8.093.

This work shows that the fractionation of Li isotopes is dependent upon the extent of water/rock interaction in terms of intensity (i.e. temperature that control primary mineral dissolution Figure 1: Concordia diagram of zircon, titanite, allanite and pyrochlore analyses from a meta-carbonatite sample (HwCr-001) and secondary mineral formation in geothermal systems). defining a linear array with upper and lower intercepts of 436 and 71 Altogether, this study highlights that the use of Li isotopic Ma. However, this ‘simple’ linear array obscures the complex systematics is a powerful tool for characterizing the origin of behavior of different isotope systems in the accessory phases and geothermal waters as well as the nature of their reservoir rocks. the complex geological history that led to the above pattern. [1] Millot et al. (2010) Geochim. Cosmochim. Acta 74, 1852-1871. In combination, these datasets put new constraints on the timing [2] Millot et al. (2012) Applied Geochem. of carbonatite and alkaline igneous activity and the evolution of doi:10.1016/j.apgeochem.2011.12.015 (ancestral) North America’s western continental margin from Neoproterozoic to Carboniferous times, and elucidate the applicability of different geochronometers and their sensitivity to amphibolites facies metamorphism in this set of unusual high- alkaline rocks.

Mineralogical Magazine | www.minersoc.org 2112 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Modelling long term carbon and Concentration and transport of sulphur cycling over the Proterozoic solutes drive by transpiration at the 1* 1 edge of a Prairie Pothole wetland ENJAMIN ILLS NDREW ATSON OLIN B M , A J. W , C HRISTOPHER ILLS ARTIN OLDHABER RAIG 2 3 C T. M *, M B. G , C A. GOLDBLATT AND TIMOTHY M. LENTON STRICKER 1 University of East Anglia, Norwich, UK. United States Geological Survey, Denver, CO, 80225, USA [email protected] (* presenting author) *presenting author ([email protected]) [email protected] 2University of Victoria, Victoria, British Columbia, Canada. The Prairie Potholes region (~715,000 km2) extends from Alberta, [email protected] 3University of Exeter, Exeter, UK. Canada to Iowa, USA. Retreat of Pleistocene glaciers left millions [email protected] of pothole-like depressions that are internally drained. Topographically low, groundwater discharge wetlands tend to be Current zero-dimensional carbon and sulphur cycle models saline (often Ca-Mg-SO4-HCO3) due to reaction of groundwater provide estimates of O2 and CO2 concentration over the Phanerozoic eon, and show a reasonable correlation with available proxys [1][2]. with glacial till rich in pyrite, gypsum, and calcite. However, several In this work we attempt to further extend these techniques to other processes influence discharge wetland chemistry, including address conditions throughout the Proterozoic. As well as the plant transpiration at the wetland edge. This process can concentrate controlling processes in the Phanerozoic, this model must include the interaction of the surface system with the mantle, the steady solutes and change hydrologic gradients at the wetland margin accumilation of carbon in the crust and the change in removal causing it to alternate between a source and sink of water and solutes 18 2 34 pathways as the continental area expands – processes which have to the wetland. We used δ OH2O, δ HH2O, and δ SSO4 values of been addressed individually in previous work [3][4][5]. groundwater and wetland water to investigate this process at the edge Initial results show that the accumilation of crustal carbon in the combined model agrees well with previous modelling, and the of wetland P1 in the Cottonwood Lake study area near Jamestown, predicted surface temperature and isotopic fractionation fall within North Dakota (USA). reasonable limits. However, the baseline model does not predict the Solutes (including SO4) were least concentrated in wetland P1 expected low oxygen concentration throughout the Proterozoic, water and deep (several meters below ground surface) groundwater instead predicting a stable concentration of around 0.2-0.5 PAL (present atmospheric level). The conclusion is that important upgradient of P1. Solutes were more concentrated in mid-depth processes may be missing. (150 cm) to shallow (60 to 90 cm) groundwater at the edge of the Thankfully there are many candidates for the missing process wetland due to plant transpiration. Transpiration did not affect (e.g. reduced organic burial due to limited nutrient delievey [6]), and δ18O / δ2H values of mid-depth groundwater samples which we therefore use our model framework as an assesment tool: for H2O H2O were similar to deep, upgradient groundwater and fell on the each possibility, model predictions for O2, CO2, temperature and the 18 isotopic fractionation of carbon and sulphur are compared to all meteoric water line (δ OH2O from -14.6 to -12.0‰). Deep and available geochamical proxies, allowing the evaluation of these 34 mid-depth groundwater samples also shared similar δ SSO4 values (- mechanisms, and hopefully the beginnings of a combined model for 18.2 to -15.1‰). Water from P1 fell below the meteoric water line Earth evolution. 18 34 (δ OH2O=-4.6‰) and had more positive δ SSO4 values (-4.2‰). Shallow groundwater from the wetland edge had δ18O / [1] Bergman et al. (2004) Am. J. Sci. 304, 397-437. [2] Berner H2O 2 34 (2006) Geochim. Cosmochim. 70, 5653-5664. [3] Hayes and δ HH2O and δ SSO4 values that were intermediate between deeper Waldbauer (2006) Phil. Trans. R. Soc. B 361, 931-950. [4] Bjerrum 34 groundwater and wetland water. A plot of δ SSO4 versus the and Canfield (2004) Geochem. Geophys. Geosyst. 5, Q08001. [5] Sleep and Zahnle (2001) J. Geophys. Res. 106, 1373-1399. deuterium offset showed shallow groundwater to be a mixture of [6] Lenton and Watson (2004) Geophys. Res. Lett. 31, L05202. deeper groundwater and wetland water. Samples taken at different times of day located differently along the mixing line indicating dynamic mixing. Samples collected earlier in the day showed a smaller contribution of wetland water than samples collected later in the day. This may be a result of a diurnal cycle of the hydrological gradient at the wetland edge due to plant transpiration. This study clearly demonstrated the use of natural abundance isotope systems for investigating this hydrochemical process and the potential impact of plant physiology on wetland geochemistry.

Mineralogical Magazine | www.minersoc.org 2113 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Current Status of Phosphate The evolution of clay minerals and rift structure in Zhanhua Depression, China (U-Th)/He Thermochronology of Meteorites Zhao Ming1*, Ji Junfeng2, Chen Xiaoming3, Wu Changzhi4, Wu Bing5 and Pan Yuguan6 1* 2 KYOUNGWON MIN , SEUNG RYEOL LEE 1Nanjing University, China, Earth Sciences and Engineering, 1University of Florida, Department of Geological Sciences, [email protected] Gainesville, USA, [email protected] (* presenting author) 2Nanjing University, China, Earth Sciences and Engineering, 2 Korea Institute of Geoscience & Mineral Resources, Daejeon, [email protected] Korea, [email protected] 3Nanjing University, China, Earth Sciences and Engineering,

[email protected] Traditional whole-rock (U-Th)/He methods applied to 4Nanjing University, China, Earth Sciences and Engineering, meteorites commonly yield apparently younger ages than expected [email protected] from other thermochronologic tools, suggesting that (U-Th)/He 5 systems are disturbed by thermal event(s) after the primary cooling. Nanjing University, China, Earth Sciences and Engineering, However, recent investigations applied to phosphates at a grain scale [email protected] 6 have revealed that some of the phosphate (merrillite, apatite) grains Nanjing University, China, Earth Sciences and Engineering, retain their pristine (U-Th)/He ages, allowing for determination of the [email protected] temporal and temperature conditions that their parent bodies experienced during the primary cooling or shock events. In this Introduction, Results and Conclusion contribution, we aim to explain the current status of the (U-Th)/He Zhanhua Depression is located in Bohai Bay Basin, China. The methods applied to extraterrestrial phosphates. depression has an area of about 3800km2. It is a major oil and gas For unshocked meteorites, the single-grain (U-Th)/He methods exploring district in the basin. provide a unique way to determine absolute ages when the meteorites The study on diagenesis of clay minerals in Zhanhua Depression have passed through temperatures below ~200 °C. Recent stepped shows that the disordered mixed-illite/smectite (R I/S) and kaolinite heating experiments indicate that the closure temperatures of 0 in the Neogene were formed at the burial depths <2000m during the merrillite and chlorapatite are generally in the range of 85-145 °C and 7-108 °C, respectively, for a wide range of cooling rates (0.1– 100 post-rift in Zhanhua Depression, while the appearance of the ordered °C/Ma) and at a diffusion domain radius of 50 μm. Two examples of mixed-illite/smectite (Ṟ1I/S) in the Paleogene at the burial depths the single-grain (U-Th)/He thermochronometry used to constrain low >2000m and the disappearance of kaolinite at the same depths were T thermal histories are for the Acapulco and St. Séverin meteorites symbolized as the syn-rift in the depression. This regularity is whose pristine ages are well consistent with the medium-to-high T referred to the burial depths, which are controlled by the cooling curves. For shocked meteorites, the phosphate (U-Th)/He paleotemperatures in the evolution of the clay minerals. ages can provide crucial information regarding shock temperature By using the chlorite geothermometer [1, 2, 3], the forming conditions. Due to the high He diffusivity in phosphates, the transient temperature of chlorites during the rift period in the Paleogene is shock event causes significant fractional loss of He (f ), which can He calculated as 135-180ć in Zhanhua Depression. The relationship be utilized for thermal modeling and peak T estimation. Because between the chlorite diagenetic temperature and its burial depth most of the phosphate crystals are severely fractured, most likely indicates that the paleogeothermal gradient is about 38ć/km in the during the shock event, diffusion domains are smaller than crystals; therefore, requiring detailed petrographic examination and image Paleogene in Zhanhua Depression. It is higher than the present analysis of phosphate grains for modeling. This approach has been geotemperature (34.5-32ć/km [4]). This phenomenon was applied to the Los Angeles, ALHA84001, Zagami and EETA79001 attributed to the evolution of the structural dynamics in the rifted Martian meteorites. Some of the results from this approach indicate basin [5, 6]. bias from the peak T estimated from traditional shock recovery experiments. (U-Th)/He study of Zagami indicates relatively high Acknowledgements: This work is supported by the National peak T (> 400 °C); whereas, shock recovery experiments yield minor Natural Science Foundation of China (Project number 40772027, shock conditions (post-shock T ~ 60 °C). It is unclear what causes 41172040). The authors would like to thank the help from the such a large discrepancy. In order to improve phosphate (U-Th)/He session convenors of the Goldschmidt 2012 Conference. methods, the following issues need to be thoroughly addressed. First,

because the morphology-based α recoil correction is essentially [1] Battaglia (1999) Clay and Clay Minerals, 47, 54-63. [2] Nieto impossible for meteoritic samples, an alternative way of avoiding this correction has been suggested. Although there is a tendency that large (1997) Europe Journal of Mineral, 9, 829-841. [3] Rausell-Colom, grains with other phases attached yield more pristine ages without α Wiewiora (1991) American Mineralogist, 76, 1373-1379. [4] recoil correction, there are some exceptional cases that are not fully Gong, Wang, Liu, et al (2003) Sci China Ser D-Earth Sci, 33, 384- understood. Second, the He diffusion properties in meteoritic apatite 391.[5] Xie, Jiao, Tang, et al (2003) AAPG Bull, 87, 99-119. [6] seem to show relatively large sample-to-sample variations, rendering Zhao, Chen, Ji, et al (2006) Acta Petrol Sin (in Chinese), 22, 2195- additional efforts to constrain the diffusion properties for various 2204 meteoritic phosphates.

Mineralogical Magazine | www.minersoc.org 2114 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Hydrocarbon adsorption on Litho-, chrono- and S-MIF-chemo- Carbonate and Silica surfaces: a First stratigraphy of late Archean Dharwar Principles study with van der Waals Supergroup, south India

interactions KAORU MISHIMA1*, RIE YAMAZAKI2, M. SATISH-KUMAR2, 3 1 1 1* TOMOKAZU HOKADA , YUICHIRO UENO VAGNER A. RIGO AND CAETANO R. MIRANDA , 1Department of Earth & Planetary Sciences, Tokyo Institute of 1Universidade Federal do ABC (UFABC), Santo Andre-SP, Brazil, Technology, Tokyo, Japan. [email protected] [email protected] (* presenting author) 2Institute of Geosciences, Shizuoka University, Shizuoka, Japan

3National Institute of Polar Research, Tachikawa, Tokyo, Japan We study the adsorption of hydrocarbon molecules on carbonate

minerals and silica surfaces by means of first-principles calculations Earth’s tectonic and climatic systems may have fundamentaly based on Density Functional Theory (DFT) with and without van der changed through the late Archean period, which is characterized by Waals (vdW) corrections. The inclusion of vdW corrections in ab- major deposition of banded iron formation (BIF) and appearance of initio methods can improve the description of these systems stromatolite reef along continental margins. Also, mass-independent particularly, the long range weak dipole-dipole interaction as well as fractionation of sulfur isotopes (S-MIF) demonstrated that Earth’s provide a fully electronic description for the interface of atmosphere and ocean were virtually oxygen-free before 2.3 Ga [1]. hydrocarbon molecules and mineral surfaces. To take into account In the late Archean, the S-MIF signature changed dramatically: the vdW dispersion forces, we used the DFT with the Dispersion- minimam '33S at around 2.9 Ga, subsequent large '33S variation Corrected Atom-Centered Potentials model (DCACP) [1] Energetic, culminated at 2.5 Ga and its sudden drop at the end of Archean. electronic, structural and kinetic properties have been determined These changes may reflect perturbation of atmospheric chemistry. for the adsorption of the representative hydrocarbons (benzene, However, almost the S-MIF record so far came from Pilbara and anthracene, naphthalene, toluene, heptane and hexane) on calcite Kaapvaal cratons, that may have been a single continent (Vaalbara) at (CaCO ) and dolomite [CaMg(CO ) ] (10-14) and quartz (SiO ) 3 3 2 2 that time [2], and thus the observed S-MIF may possibly reflect local surfaces. Our results suggest that Ca sites are the most energetically environment. It is important to test the “globalism” of the S-MIF favorable for hydrocarbon adsorption on both carbonate systems. signature for tracing the atmospheric evolution. The calculations also indicate a weak interaction between the We studied late Archean volcano-sedimentary sequence of the hydrocarbon with the bare silica surface for all hydrocarbons Dharwar Supergroup, distributed in the Chitradurga schist belt, studied. The vdW corrections strengthen the hydrocarbon-surface western Dharwar craton. Our new field mapping and zircon U-Pb bond with a corresponding reduction in the bond distance between dating allows us to reconstruct detailed lithostratigraphy. The lower the benzene and the surfaces. The inclusion of London dispersion unit (post-3.0 Ga) consists of basal conglomerate, stromatolitic forces to benzene results in an increase of 70% in the surface- carbonate, silici-clastics with diamictite, chert/BIF and pillowed molecule energy interaction. The energy barrier, for the basalt in assending order, all of which are older than 2676 Ma displacement of the hydrocarbons along the calcite and quartz SiO 2 magmatic zircon ages from dacite dyke intruded into the topmost surfaces were determined using the Nudged Elastic Band method, pillowed basalt. The upper unit unconformably overlies the pillow and adsorption energies for the most stable sites show the same lava, and consists of conglomerate/sandstone with ~ 2600 Ma order of magnitude. The highest energy barriers associated with the detrital zircons, komatiite lava, BIF and silici-clastic sequence with hydrocarbon displacements on the surfaces are of the same order of mafic volcanics. Sulfur isotope analysis of extracted sulfide of these the adsorption energies for the most stable sites. By taking into sedimentary rocks show a clear '33S-'36S correlation with a account the vdW interactions within the energy barriers in '36S/'33S slope of -0.98. This trend is similar to those reported complement to adsorption energies in a model for from Pilbara-Kaapvaal equivalents, thus could be a global signature, hydrocarbons/mineral-rocks interaction can give us a more realistic whereas G34S-'33S relation from each stratigraphic level shows description to the hydrocarbon carbonate/silicate interactions. somewhat different trend, possibly reflecting local environment

and/or postdepositional overprint.

[1] Farquhar (2000) Science, 289,756-758. [2] de Kock et al. (2009) Precambrian Res. 174, 145-154.

Figure1 - Energy barriers for benzene displacement along [48-1] direction for calcite (10-14) surface [1] Lin et al. (2007) Phys. Rev. B 75, 205131

Mineralogical Magazine | www.minersoc.org 2115 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Global oxygen isotope survey of Improved Analytical Method for lithospheric mantle: Implications for Determination of B Isotopes by the evolution of cratonic roots Magnetic Sector ICP-MS 1 2 2 2 A. MIŠKOVIĆ *, R.B. ICKERT , D.G. PEARSON , R. A. STERN , SAMBUDDHA MISRA1*, JOANNA KERR1, MERVYN GREAVES1, 3 4 M. KOPYLOVA AND B. KJARSGAARD HENRY ELDERFIELD1 1Northwest Territories Geoscience Office, Yellowknife, Canada, 1University of Cambridge; Dept. of Earth Sciences; Cambridge, UK [email protected] (* presenting author) (*presenting author: [email protected]) 2CCIM - Earth & Atmospheric Sciences, University of Alberta, Edmonton, Canada The boron isotopic composition of seawater, as recorded by 3Earth & Ocean Sciences, University of British Columbia, foraminifera, can be used as a tracer of past variations in atmospheric

Vancouver, Canada pCO2 [1, 2]. However, widespread application of B isotopes in 4Geological Survey of Canada, Ottawa, Canada geochemical studies is limited by the large relative mass requirement for high precision measurements, large memory effect, high The sub-continental lithospheric mantle (SCLM) forms the procedural blanks, artificial fractionation induced by matrix roots to the earliest crust and represents the most ancient mantle purification methods, and low matrix tolerance [3]. We present an domain on Earth. Hundreds of oxygen isotope data have been improved method for B istope ratio (δ11B) determination with low reported for various mantle domains in the past three decades, yet the full geodynamic significance of these data is largely mass consumption (5 to 10 ng-B per quintuplicate analyses), high unappreciated. When coupled to the major element systematics, precision (± 0.5‰, 2σ), low blanks (< 9 pg-B/ml), and high matrix oxygen isotopes have the potential to illuminate the longstanding tolerance using Element XR® Single Collector ICP-MS (figure). The conundrum of the origin of highly depleted lithospheric roots present ICP-MS method is optimised for analysis of < 0.5 mg beneath the Archean crust given that the current debate on their foraminifera samples. genesis is centred on quantifying the relative contributions of mantle Preliminary analyses of B standards following standard – sample plumes (asthenospheric source) and subduction zone processes (lithospheric source). bracketing technique gave external precision (quintuplicate) of ± 0.50‰ independent of analyte concentration (4 ppb – 10 ppb). We present isotope analyses for 61 grains of olivines extracted Moreover, this new ICP-MS method has relatively large tolerance for from peridotite xenoliths entrained by kimberlites and pericratonic Na, Mg, and Ca – the dominant matrix elements in foraminiferal 18 basalts worldwide; the most extensive high-precision in situ δ O calcite and provides an improved methodology to investigate B database to date. Olivines analysed by multi-collector SIMS in this isotopic variations of planktonic and benthic foraminifera samples study were collected at: Paleogene to Jurassic Diavik and Jericho over geologic timescales. kimberlites (Slave Province), Cretaceous Somerset Island kimberlites (Rae Craton), Late Neoproterozoic kimberlites of Western Greenland (North American Craton), Middle Cretaceous to Late Mesoproterozoic Kimberly, Finsch, Letseng-la-Terae and Premier kimberlites (Kaapvaal Craton), Early Carboniferous Udachnaya pipe (Siberian Platform), and Miocene Vitim alkaline basalts.

The SCLM G18O data are normally distributed about the mean value of 5.30 ‰ (±0.22; 2V) and largely corroborate previous upper mantle compilations [1]. There is no correlation between G18O and major or trace element chemistry, rhenium-depletion ages or equilibrium pressure-temperature conditions from which the mantle xenoliths were derived. Based on the new data we find no statistical difference between the oxygen isotope composition of cratonic peridotites and modern MORB-source mantle. These observations rule out an origin for SCLM via subcretion of serpentinised oceanic lithosphere [2]. However, we cannot discriminate between the subduction of relatively unaltered oceanic lithospheric mantle versus a plume origin. Furthermore, the overlap of the SCLM data with the mean global G18O value of MORBs of 5.17‰ (±0.21; 2V) has important implications for the long-term relationship between the convecting asthenospheric mantle and refractory cratonic roots.

[1] Mattey, D., Lowry, D, and Macpherson, C. (1994) Oxygen Figure: Results of (A) Boron concentration experiment, and (B) isotope composition of mantle peridotite. EPSL 128, 231-241. matrix experiment. All samples analysed following standard – sample [2] Schulze, D. (1986) Calcium anomalies in the mantle and a bracketing technique. Analyses of sample in quintuplicates. subducted metaserpentinite origin for diamonds. Nature 319, [1] Pearson and Palmer (2000) Nature. 406, 695-699. 483-485. [2] Hemming & Honisch (2007) Proxies in late Cenozoic [3] Canil, D. and Lee, C.-T. A. (2009) Were deep cratonic mantle paleoceanography, 1 (17). 717-734 roots hydrated in Archean oceans? Geology 37, 667-670. [3] Aggarwal et al., (2003) Chemical Geology 199, 331-342

Mineralogical Magazine | www.minersoc.org 2116 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Potential of Microbiologically Isotope fractionation of selenium Induced Mineralisation to Increase during sorption to iron oxide and Geologic CO2 Storage Security iron sulfide minerals 1 2 1* 1 2 3 ANDREW C. MITCHELL *, ADRIENNE J. PHILLIPS , ELLEN KMITCHELL , R-M COUTURE ,TMJOHNSON , PRD MASON 2 2 2 1 LAUCHNOR , JAMES CONNOLLY , LOGAN SCHULTZ , ROBIN AND PVAN CAPPELLEN 2 2 GERLACH AND ALFRED B CUNNINGHAM . 1University of Waterloo, Waterloo, Canada (*presenting author: 1Institute of Geography and Earth Sciences, Aberystwyth University, [email protected]) Aberystwyth, UK, [email protected] (* presenting author) 2University of Illinois, Urbana, USA 2Center for Biofilm Engineering, Montana State University, 3Utrecht University, Utrecht, The Netherlands Bozeman, USA, Sorption and abiotic reduction are important processes influencing the mobility and cycling of Se in natural environments. Although During the operation of Geologic Carbon Capture and Storage these processes have received increasing attention in recent years, the (CCS) and the injection of supercritical CO2 into underground associated isotopic fractionations are poorly known [1, 2]. In this formations, microbe-rock-fluid interactions occur. These study we determined the rates of reaction and isotopic fractionations interactions may be important for controlling the ultimate fate of the of Se(IV) and Se(VI) during sorption to iron oxides (2-line injected CO2, and may also be manipulated to enhance the storage of ferrihydrite, hematite and goethite) and iron sulfides (FeS and FeS2) the CO2, via mineral-trapping, solubility trapping, formation trapping, and leakage reduction. in batch reactor experiments. No change in Se oxidation state was We have demonstrated that engineered microbial biofilms are observed when Se(IV) and Se(VI) sorbed to iron oxides. In contrast, capable of enhancing formation, mineral, and solubility trapping in XANES spectra showed evidence of reduction on the iron sulfides. carbon sequestration-relevant formation materials. Batch and flow Reaction rates were obtained using inverse modeling of dissolved Se experiments at atmospheric and high pressures (> 74 bar) have concentration time series, following the mixed-reaction modeling shown the ability of microbial biofilms to decrease the permeability approach of [3]. Sorption rates were highest in the Se(IV)-goethite of natural and artificial porous media [1], survive the exposure to system, while Se(VI) sorbed slowly on 2-line ferrihydrite and not at scCO2 [2], and facilitate the conversion of gaseous and supercritical all on hematite and goethite. Reduction was fastest in the Se(IV)-FeS CO2 into long-term stable carbonate phases as well as increase the solubility of CO2 in brines [3]. system and slowest for Se(VI)-FeS2. Changes in the isotopic Ongoing microscopy and modelling studies aim to understand composition of aqueous Se were monitored as a function of time. The these processes at both the pore- and core-scale in order to results revealed the absence of measurable equilibrium isotope facilitate larger scale understanding and potential manipulation for fractionation for all systems studied. Kinetic fractionation was biologically based CCS engineering [4,5]. Successful development observed in the case of Se(IV) sorbing to 2-line ferrihydrite and of these biologically-based mineralisation concepts could result in 82/76 Se(IV) being reduced by FeS2. Figure 1 illustrates the į Se trends microbially enhanced carbon sequestration strategies as well as CO2 leakage mitigation technologies, which can be applied either before of aqueous and solid-bound Se(IV) sorbing to 2-line ferrihydrite. The CO2 injection or as a remedial measure around injection wells. data follow the standard Rayleigh fractionation model, except for the last two time points, as the system approaches equilibrium. [1] Mitchell et al. (2009) International Journal of Greenhouse Gas Control 3, 90-99. [2] Mitchell et al.(2008) Journal of Supercritical Fluids 47, 318- 325. [3] Mitchell et al. (2010) ES&T 44, 5270-5276. [4] Schultz et al. (2011) Microscopy Today 19, 12-15. [5] Cunningham et al.(2011) Energy Procedia 4, 5178-5185.

Figure 1: Se(IV) sorption to 2-line ferrihydrite. Circles show PHDVXUHG į82/76Se of the remaining Se(IV) in solution, squares the FDOFXODWHGį82/76Se of Se(IV) sorbed to 2-line ferrihydrite. The open symbols correspond to the two last samples collected, whose data were excluded when fitting the data with the Rayleigh fractionation model. (UURUEDUVLQGLFDWHWKHSUHFLVLRQRIį82/76Se measurements.

[1] Johnson (2003) Geochim. Cosmochim. Acta 67, 413-419. [2] Johnson (1999) Geochim. Cosmochim. Acta 63, 2775-2783. [3] Zhang (2005) Environ. Sci. Technol. 39, 6101-6108.

Mineralogical Magazine | www.minersoc.org 2117 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Dislocation microstructures of Local structure of Al in Al-Zn ferropericlase at high pressures. hydroxide coprecipitates 1* 2 1* 1 2 NOBUYOSHI MIYAJIMA AND TETSUO IRIFUNE AKANE MIYAZAKI , KAORI ETOU , MAYUMI ETOU , KOTARO YONEZU3, IOAN BALINT4, AND TAKUSHI YOKOYAMA5 1Bayerisches Geoinstitute, Bayreuth Universität, Bayreuth, Germany, [email protected] 1Japan Women’s University, Tokyo, Japan, [email protected] 2Geodynamics Research Center, Ehime University, Matsuyama, (* presenting author) Japan, [email protected] 2Faculty of Science, Kyusyu University, Fukuoka, Japan 3Faculty of Engineering, Kyusyu University, Fukuoka, Japan Introduction 4Institute of Physical Chemisty, Bucharest, Romania The rheological behavior of magnesium silicate perovskite (MgPv) and ferropericlase (Fp) at high pressure and temperature is Al-Zn hydroxide coprecipitate indispensable for discussing dynamics of the Earth’s lower mantle. Zn2+ adsorption onto alumina, which represents the behavior of Deformation of plastically weaker Fp than coexisting MgPv is likely heavy metal ions in soil systems, can be devided into three processes; to be responsible for bulk strain of the rock, if it develops a adsorption due to formation of inner-sphere complex, desorption of 2+ 3+ sufficient grain connectivity in a fabric development at high Zn accompanied with dissolution of Al , and then re-adsorption of 2+ temperature. Particularly, lattice preferred orientations (LPO) of the Zn [1]. Recently, the final product of the above three processes was polycrystalline Fp can be important to explain observed seismic found to have AlO4 species in its structure [2]. The formation of AlO4 2+ anisotropies in the bottom of Earth’s lower mantle, so called “D’’ was induced by Zn adsorption and it relats deeply to the dissolution 3+ layer”. For understanding deformation mechanisms to create a LPO and re-adsorption of Al . There are two possible assignement for the pattern, dislocation microstructures of Fp under lower mantle AlO4 species; one is Keggin-like structure, and the other is 2+ 3+ conditions are very important, because dislocation creep substitution of Zn by Al in the structure of zinc aluminate, mechanisms could become one of dominant mechanisms in the D’’ ZnAl2O4. Because the adsorption experiments were performed at layer. To discuss the influence of pressure on the active slip system constant pH of 6.5, where Keggin is not stable, the formation of in Fp, we report dislocation microstructures of Fp in a pyrolite Keggin-like structure seems to be unlikely. On the other hand, 3+ mineral assemblages synthesized at 44 GPa and 2073 K [1], in ZnAl2O4 is a member of the spinel family and Al can substitute four 2+ comparion to those of lower pressure samples, by using TEM. coordinated Zn in its structure. Zinc aluminate is known to be Results and Conclusion prepared by calcining Al-Zn hydroxide coprecipitates [3]. In the 2+ In the pyrolite mineral assemblage, MgPv contained a few process of Zn adsorption onto alumina, it is possible that the 2+ 3+ dislocations and Fp displayed a high density of dislocations (Figure desorbed Zn and dissolved Al coprecipitate to form zinc 1). In a Fp grain, straight long screw dislocations with b = 1/2[1-10] aluminate-like structure as the final products of adsorption. In order were nucleated on the (110) and/or (11-1) planes (Figure 1a) and the to examine this possibility, Zn-Al hydroxide coprecipitates having other dislocations with b = 1/2[01-1] was also along the (011) plane various Zn/Al ratios were prepared and chemical states of Al was 27 (Figure 1b) in the same grain. compared to the final product of adsorption using Al MAS NMR. 27 Dislocation microstructures of Fp synthesized at high Al MAS NMR spectra of the coprecipitates 27 temperatures and different pressures from 0 to 44 GPa were Figure 1 shows the Al MAS NMR spectra of coprecipitates compared in the TEM images. The highest pressure sample indicate prepared by hydrolysis of mixed solution of zinc and aluminum that an active slip system of 1/2<110>{110} in Fp, consistent with nitrates. Peaks at around 60 ppm, which correspond to AlO4 species, previous experimental studies at lower pressures. The characteristic increased by decrease of Zn/Al ratios. Fig. 1 shows that the AlO4 textures of straight screw dislocations along a specific crystal species can be formed by coprecipitation of Al and Zn, without orientation strongly imply that the Peierls friction for movement of calcination. AlO4 species increased by lowering Zn/Al ratios. 2+ 1/2<110> dislocations in Fp increases with increasing pressure. The Therefore, less Zn seems to cause dislocation microtextures are compared with a current theoritical more isomorphic subsbitution by Al 3+. The shape of 27Al MAS NMR study of dislocation mobilities in MgO [2]. Zn/Al=10 spectra of the coprecipitate with low Zn/Al ratio is almost identical 3 to that of the final product of Zn2+ 2 adsorption onto alumina. Therefore, 1 0.1 it is highly possible that Zn2+ 0.02 adsorption onto alumina induced 100 0 -100 the formation of Zn-Al hydroxide Chemical shift [ppm] coprecipitate having zinc 27 aluminate-like structure. Figure 1: Al MAS NMR Figure 1: Bright field TEM micrographs of Fp in a pyrolite mineral spectra of the Zn-Al assemblage at 44 GPa and 2073 K. [1] Miyazaki et al, (2003) hydroxide coprecipitates Geochem. Cosmoshim. Acta 67, [1] Irifune, Shinmei, McCammon, Miyajima, Rubie & Frost (2010) 3833-3844. Science 327, 193-195. [2] Cordier, Amodeo & Carrez (2012) [2] Miyazaki et al, (2011) Goldschmidt, 08/3045. Nature 481, 177-180. [3] van de Laag et al, (2004) J. Eur. Ceram. Soc. 24, 2417-2424.

Mineralogical Magazine | www.minersoc.org 2118 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts High-pressure and high-temperature Influence of DOM quality on arsenic experimental study of carbon isotope mobilization in a Bangladesh Aquifer 1,2* 1 fractionation in the Mg-Si-C-O NATALIE MLADENOV , DIANE M. MCKNIGHT , BAILEY 1 1 1 system SIMONE , TERESA LEGG , DIANA NEMERGUT , JESSICA 1 3,4 3,4 EBERT , KATHLEEN A. RADLOFF , AND YAN ZHENG 1* 1 SHOGO MIZUTANI , M. SATISH-KUMAR , TAKASHI 1 2 3 University of Colorado, Boulder, CO, USA, YOSHINO , AND MUTSUMI KATO [email protected], [email protected], 1 Department of Geosciences, Shizuoka University, Shizuoka, Japan, [email protected], [email protected], 2 ISEI, Okayama University, Misasa, Japan [email protected] 3 Graduate School of Science, Chiba University, Chiba, Japan 2Kansas State University, Manhattan, KS, USA, [email protected] (* presenting author) Carbon is the fourth most cosmic abundant element in the solar 3Queens College, City University of New York, Flushing, NY, USA system. It has a key role in the melting phase relations of mantle 4LDEO, Columbia University, Palisades, NY, USA, rocks and can move within mantle as carbonate rich melts [1]. [email protected], [email protected] Additionally, carbon is deposited in the ocean floor as carbonate minerals and organic matter, and is recycled into the mantle during There is broad consensus that the main mechanism for the subduction. Carbon isotopic composition serves as an efficient tool mobilization of arsenic (As) in reducing groundwater is the to understand the carbon cycle, both in the shallow and deep Earth microbial reductive dissolution of iron (Fe) oxyhydroxides driven by 13 environments. Recently, the presence of low δ C diamonds was the oxidation of labile organic matter (Figure 1). There is increasing considered to provide evidence for deep cycling of surface carbon evidence that the chemical quality of dissolved organic matter of the organic matter origin [2], however recent experimental results (DOM) may have an additional influence on arsenic (As) in the Fe-C system suggests an alternate possibility of light carbon mobilization in reducing groundwater. [1] For example, humic in the core [3]. Therefore, it is essential to understand the carbon substances, a major part of the DOM pool, are known electron isotope fractionation at mantle P-T conditions. Here, we present shuttles that may also be involved in metal complexation (Figure 1). results on experimental determination of partitioning of carbon We used UV-vis absorbance and novel fluorescence techniques to isotopes at high-pressure and high-temperature conditions, characterize DOM in groundwater with dissolved As concentrations analogous to melting of carbonated mantle in the presence of ranging from 2 to >400 μg/L and spanning a wide spatial extent in graphite/diamond, and discuss the carbon movement in the mantle. Araihazar, Bangladesh. For a subset of wells, we also determined % High-pressure experiments were performed in the Mg-Si-C-O fulvic acid and performed elemental and 13C-NMR analyses on system using a Kawai type multi-anvil high-pressure apparatus at the fulvic acid isolates. Institute for Study of the Earth's Interior, Okayama University, Our results consistently showed that terrestrially-derived Misasa, Japan. Starting materials comprise of natural enstatite, aromatic organic compounds with low protein-like character were synthetic magnesite (δ¹³C = -32.8‰), San Carlos olivine and pure found where dissolved As concentrations are elevated. Moreover, graphite (δ¹³C = -16‰), that were mixed in the molar ratio 3:2:1:1 the lowest As concentrations were found in village wells that had or 3:2:1:3. This mixture is assumed as simplified carbonated sewage pollution-derived DOM signatures. Together with highly harzburgite in a upper mantle. Experiments were carried out at significant relationships between arsenic and aromaticity and pressures of 5 and 10 GPa at varying temperature conditions fluorescence of the fulvic acid isolates, our results provide strong between 1100 ºC and 1800 ºC. Retrieved samples from HPHT evidence that humic substances have an important role in arsenic experimental runs were mounted in epoxy and cut into two halves mobilization and potentially its maintenance in solution (Figure 1). and polished. One half was used for petrographic observations and chemical analysis using an electron microprobe and the other half for carbon isotope measurements. Run products were mechanically and/or chemically separated and carbon isotope measurements were carried out using a conventional gas source isotope ratio mass spectrometer (IRMS). Preliminary results indicate that runs at 5 GPa and above 1500 ºC have melted and the chemical composition of the melt varied widely, such as C-rich melt or Si-rich melt. Carbon isotope results show considerable partitioning between graphite/diamond and Figure 1: Conceptual diagram showing the “reductive dissolution” carbonate melt at temperatures and pressures corresponding to hypothesis (left) and an expanded “humics-enhanced reductive upper mantle conditions. We discuss the carbon isotope systematics dissolution” hypothesis (H2; right) in which labile DOM and during melting of carbonated mantle and implications for deep reactive DOM (including humic quinones) serve to donate and carbon cycle based on our experimental results. shuttle electrons, and are involved in complexation reactions. [1] Dasgupta & Hirschmann (2006) Nature, 440, 659-662 [2] Sedimentary organic matter sources of labile and reactive DOM Walter et al., (2011) Science, 334, 54-57 [3] Satish-Kumar et al., shown in brown. (2011) Earth Planet. Sci. Lett. 310, 340-348 [1] Mladenov, N. et al. (2010) Env. Sci. Tech. 52, 47-59.

Mineralogical Magazine | www.minersoc.org 2119 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Petrography and composition of iron GOLIATH: A systems biology, formation from the ca. 3.8 Ga Nulliak geochemical and physiological Supracrustal Association (northern approach to discern microbial Labrador, Canada) transformations of Mercury and *1 1 ALEKSANDRA M. MLOSZEWSKA ; RASMUS HAUGAARD ; Methylmercury. 1 1 1 KURT O. KONHAUSER JAMES G. MOBERLY , CARRIE L. MILLER , RICHARD A. HURT, 1 1 1Earth and Atmospheric Sciences, University of Alberta, Edmonton, JR, STEVEN D. BROWN , SCOTT C. BROOKS , CRAIG C. 1 1 1 Canada, [email protected] (*corresponding author) BRANDT , MIRCEA PODAR , ANTHONY V. PALUMBO , 1* DWAYNE A. ELIAS Banded iron formations (BIFs) are important sources of 1Oak Ridge National Laboratory, Oak Ridge, USA, [email protected] information on the composition of ancient seawater [1,2]. Eoarchean (* presenting author) BIFs in particular may disclose information on the nutrient levels bracketing the evolution of early microbial metallo-enzymes. Only a BACKGROUND: Mercury (Hg) contamination is a global limited amount of pre-3.6 Ga year old BIFs are know, and chemical concern. Hg methylation is an important biogeochemical process, sediments from the ca. 3.8 Ga year old Nulliak Supracrustal which generates the potent neurotoxin monomethylmercury Association of northern Labrador (Canada) [3] offer an exciting (MeHg). Net MeHg production in aquatic ecosystems is linked to opportunity to expand our data base. environmental and geochemical parameters along with electron We present new petrographic and geochemical data on these Fe- donor and acceptor availability. Recently we found that methylating and Si-facies iron formations, by integrating geochemical communities contained high populations of Desulfobulbus and relationships observed between minerals in thin section and whole Geobacter spp. To gain a deeper understanding of the microbial rock chemistry. This approach provides an important framework for community populations invlolved in, and geochemical influences on, studying the chemical variations in these sediments, on several Hg methylation, physiological and meta-omic analyses were scales. Preliminary results show that the Nulliak sediments are performed. METHODS: Intact sediment cores from two relatively aluminous (Al2O3>1 wt%), with correspondingly high methylating sites (NOAA, upstream; New Horizon, downstream) and abundances of Zr (up to 20 ppm) and other high-field strenght a background site were collected and used to construct sediment elements (e.g., Nb, Hf), suggesting a non-trivial detrital component. microcosms from different depths with 6 different carbon/electron These chemical sediments contain noteworthy abundances of Cr, Ni, sources. All microcosms were spiked with Hg stable isotope tracers Zn, Sr, and Ba, while other elements tend to be <25 ppm. The high to enable quantification of both Hg methylation and MeHg Ni and Zn abundances correlate well with previous studies on demethylation and incubated under anaerobic conditions in the dark Eoarchean-aged iron formations, suggesting that these metals were for 48 hours at room temperature. DNA from the original core found globally in high concentrations during the Eoarchean [3,4]. material and incubations were hybridized to functional gene arrays Rare earth element and yttrium profiles tend to show seawater-like and sequenced via 454 16S rRNA gene pyrosequencing. anomalies (LREEmethanol and ethanol but not by acetate, lactate, a measure of balanace between hydrothermal- and terrestrial inputs propionate or cellobiose, while downstream at New Horizon affecting the composition of Eoarchean seawater composition as cellobiose stimulated methylation relative to unamended controls. reflected in BIFs. Meta -genomic, -transcriptomic, and -proteomic analyses as well as 454 pyrosequencing are currently underway. CONCLUSIONS: [1] Bjerrum and Canfield (2002) Nature 417, 159-162 The multidisciplinary combination of the above approaches are being [2] Konhauser et al. (2009) Nature 458, 750-753 [3] Nutman et al. (1989) Canadian Journal of Earth Sciences 26, employed together for the first time in order to more 2159-2168 comprehensively ascertain the influence of geochemistry on the [4] Mloszewska et al. (2012) Earth and Planetary Science Letters microorganisms, genes, and gene products that are differentially 317-318, 341-342. present, abundant and expressed in active MeHg generating ecosystems.

Mineralogical Magazine | www.minersoc.org 2120 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts The magmatic and metasomatic Deglacial forcing of rapid formation of zircon in the Nechalacho deoxygenation and seafloor ecological deposit at Thor Lake, Northwest change, Santa Barbara Basin, CA

1* 2 Territories, Canada SARAH E. MOFFITT , TESSA M. HILL

1* 1 VOLKER MÖLLER , ANTHONY E. WILLIAMS-JONES 1University of California at Davis, Bodega Marine Laboratory, Bodega, [email protected] (* presenting author) 1McGill University, Earth and Planetary Sciences, Montreal, Canada, 2University of California at Davis, Bodega Marine Laboratory, [email protected] (* presenting author) Bodega, [email protected]

The Nechalacho Rare Metal Deposit represents a world-class Background resource of REE, Y, Nb, Ta, Zr and Ga. Two densely mineralized Deglacial sediment from Santa Barbara Basin (SBB) are high- horizons are hosted in intensely altered rocks of the upper part of resolution records of regional climate, intermediate and surface the Nechalacho Layered Syenite Suite. These evolved, fluorine-rich water processes, and benthic ecology. Patterns of bottom water peralkaline rocks are dominated by acmite, annite, sodalite, oxygenation in sediment records, and thus the presence of Oxygen nepheline and feldspars. Primary REE- and HFSE-minerals include Minimum Zones (OMZs), can be reconstructed by proxy using the eudialyte, zircon, pyrochlore, britholite and Na-zircono-silicates. oxygenation and environmental tolerances of modern taxa. We During alteration, eudialyte syenites were converted to an construct a record of deglacial community ecology, intermediate assemblage of zircon, quartz, magnetite and phlogopite. Secondary water oxygenation and coastal oceanography for SBB (34q 15’N, REE- and HFSE-bearing phases in the two REE-mineralized 119q 45’W) using a core from the northwestern basin slope at 418 horizons comprise zircon, fergusonite, allanite-(Ce), bastnäsite- m water depth (MV0811-15JC). (Ce), synchisite-(Ce), parisite-(Ce), monazite and columbite[1]. Results The average whole rock content of ZrO2 ranges from 2 to 3 wt. The 9.2m core, which spans 4-16ky, is completely bioturbated. % and locally exceeds 10 wt. % in the deposit, making zircon an Significant faunal community deoxygenation horizons are evident at important rock-forming mineral. Three textural types of this mineral deglacial Termimation 1A (~14.5 ky) and 1B (~10.9 ky), demarcated have been recognized: 1. rare magmatic phenocrysts in fresh or by the loss of ostracod, mollusc and brittle star fossils. The faunal partially altered syenite; 2. quartz-hosted euhedral zoned crystals in record has high-resolution structure across taxa groups, indicating the upper mineralized zone; 3. unzoned subhedral crystals that stressful hypoxic events occur very rapidly at this depth. Results intergrown with quartz in pseudomorphs after eudialyte in the lower indicate the capacity for both rapid and sustained expansion of mineralized zone. OMZs, the gradation of biological responses, and the spatial Based on new Laser ICP-MS and electron microprobe data, oceanographic processes that impact oxygenation across the coastal magmatic zircon has a low trace element content (e.g., 80 to 6500 basin feature through the deglaciation. ppm REE) and displays heavy REE-enriched, near-linear chondrite- normalized profiles with strong positive Ce and negative Eu anomalies (avg. Ce/Ce*=3.4, avg. Eu/Eu*=0.44). Secondary type 2 and 3 zircon varies widely in composition, is strongly enriched in REE, Y, Nb and F, has elevated P and displays non-linear chondrite- normalized REE profiles with weak or absent Ce anomalies and strong Eu anomalies. Type 2 zircon has an average content of 2.3 wt. % REE, 1.1 wt. % Y and 1.3 wt. % Nb, has light and heavy REE enriched rims and cores respectively and contains significant fluorine. Relict magmatic cores and rims in the upper zone are distinguished by their low REE-contents and positive Ce anomalies which are comparable to type 1 zircon. Secondary zircon in the lower zone (Type 3) is strongly enriched in heavy REE and contains Figure 1: Spetangoid heart urchin fossills in deglacial marine 2.8 wt. % REE, 1.7 wt. % Y and 1.6 wt. % Nb on average. sediment, Santa Barbara Basin, CA. Note the biological orientation The HFSE mineralogy suggests that miaskitic and agpaitic rocks of the respiratory structures, indicating preservation at the time of occurred in close spatial association. Metasomatic-hydrothermal death. replacement of both magmatic zircon and zircono-silicates was

important for the formation of REE-enriched varieties of zircon. A

possible mechanisms for the incorporation of such high levels of

the REE is the formation of hydrated varieties at the alteration stage.

[1] Sheard, E.R, Williams-Jones, A.E., Heiligmann, M., Pederson, C and Trueman, D.L. (2012) Controls on the concentration of zirconium, niobium, and the rare earth elements in the Thor Lake Rare Metal Deposit, Northwest Territories, Canada Economic Geology 107, 81-104.

Mineralogical Magazine | www.minersoc.org 2121 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Assessing the role of Holocene sapropels on the Black Sea methane cycle 1* 1 JOSÉ M. MOGOLLÓN , SABINE KASTEN 1Alfred Wegener Institute for Polar and Marine Research, [email protected] (* presenting author) [email protected]

Sapropels, sedimentary intervals rich in organic matter, represent a substantial carbon source which directly affects the sedimentary redox conditions in marine sediments. While recently- deposited sapropels produce a shoaling of the redox zonation, the long term effect of sapropelic sediments once these become buried over several millennia and lose their most labile carbon fraction requires further addressing. In the northern Black Sea, the changing limnic to marine conditions due to the flooding of the Bosphorous straight and subsequent connection with the Mediterranean Sea circa 9.5 kyr before present (BP), led to local geochemical conditions which favored ocean stratification and an increase in the amount of organic matter reaching the sediment between 8.0 and 3.5 kyr BP. Through reactive transport models which focus on the methane cycle, we track the geochemical effects of the sapropel since its initial deposition up to present time. Our results reveal that, from the onset of their deposition, sapropels heavily influence the methane cycle by controlling the position of the sulfate-methane transition (SMT) through organoclastic sulfate reduction. Nevertheless, the influence of the sapropels on methanogenesis will ultimately depend on the time required for the sapropel to be buried below the SMT. Consequently, methane formation will be favored in locations with high sedimentation rates, or locations receiving turbidites and slumps, such that the sapropel can be quickly buried into the methanogenic zone.

Mineralogical Magazine | www.minersoc.org 2122 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Investigating geochemistry and the Estimation of He diffusion coefficients stable isotope (δ 18O & δ 2H) in low permeability sedimentary rocks

composition of Karde Carbonate RATAN MOHAPATRA1*, TOM AL2, AND IAN CLARK1 lake water (NE Iran) 1Earth Sciences, University of Ottawa, Ottawa, Ontario, Canada, [email protected] (*presenting author) 2Earth Sciences, University of New Brunswick, Fredericton, New MOHAMMADZADEH HOSSEIN 1, MOJTABA HEYDARIZAD2 Brunswick, Canada

1 Groundwater Research Center (GRC), Ferdowsi University of With a view toward establishing a deep geological repository for low- Mashhad, Mashhad, Iran, [email protected] (* and intermediate-level radioactive waste, a geoscientific site presenting author) characterization program has been conducted on the eastern margin of the 2 Ferdowsi University of Mashhad, Department of geology, Michigan Basin at the Bruce nuclear site. Drilling and collection of cores [email protected] within an ~ 860 m near-horizontally layered Paleozoic sedimentary sequence, resting atop the Precambrian basement, has provided an Introduction opportunity for porewater and groundwater sampling and analysis with an Karde dam's lake is a carbonate-precipitating and diamictic lake, unprecedented level of detail. This abstract presents a methodology for which supplies irrigation and potable water for more than 4 million estimating diffusion coefficients for He in low permeability sedimentary inhabitant of Mashhad city (NE Iran). In the following survey, rocks obtained from the drilling. Vertical (five depths 1, 5, 10, 15, 20) and temporal distribution of major cations and anions (especially nitrogen) in lakes water are Drill core samples (76 mm diameter) of Ordovician shale and investigated during 15 months (Jan 2010 to June 2011). limestone were preserved in the field inside N2-purged and vacuum-sealed bags; first polyethylene and then aluminized polyethylene. The samples Results were transported to the University of Ottawa where a sub core (6 mm The Calcite, Dolomite and Aragonite saturation index of lakes water diameter and ~ 20 mm long) was removed from the centre of the larger and evaluation of Na, Mg, Ca concentration in lake, local ground core and encapsulated in a stainless steel container at 1×10-2 Torr. Gas water and rock samples in ternary diagram indicate that Na, Ca and Mg concentrations are mainly governed by incongruent dissolution of accumulating in the head space by room temperature (20 ºC) diffusion was local carbonate (Mozdooran formation) and silicate (Neogen red periodically sampled for He and Ne isotopic measurements using a MAPL formation). 215-50 Noble Gas Mass Spectrometer. A typical experiment involved 5 Identification of dissolved minerals with ion activity (a) and gas measurements over a period of 24 hr. The measured He was corrected Log(aCa2+/a(H+)2) versus Log(aMg2+/a(H+)2) graph for Carbonate for air contamination using accompanying 20Ne data. The time-series of minerals and Log(aMg2+/a(H+)2) and Log(aCa2+/a(H+)2) versus Log (aNa+/a(H+)2) for silicate minerals show that carbonate minerals He concentrations in the head space are treated as an out-diffusion "Calcite and Dolomite" and silicate minerals "Kaolinite, Laumontite experiment and numerical simulations were conducted to estimate the He and Clinochlore" are the dominate dissolved minerals within dam diffusion coefficients by matching simulated out-diffusion profiles to the lake water. Vertical distribution of N in lake water shows significant measured data. Simulations were conducted by running the reactive + - increasing in NH4 and NO2 concentrations with depth when the - transport model MIN3P under the control of the parameter estimation NO3 concentration decreases. Principal Component Analysis (PCA) of hydrochemical analyses revealed 3 components which explain code, PEST. 67% of the variance observed. In the first component, strong In general, there is a good match between the measured He data and 2+ - -11 2 relationship between EC, TDS, Mg , HCO3 and hardness reflect the simulations (Fig. 1); Dp values ranging from 1 to 4 × 10 m/s. carbonate weathering. The variables in the second component are However, samples from a 70 m interval that straddles the Blue Mountain + NH3, NH4 , dissolved oxygen and depth. All the variables are directly Formation shale and the underlying Cobourg Formation limestone are an related except dissolved oxygen which has inverse relationship with this component. This factor represents high Organic production in exception. This is a zone with high organic carbon content and the He Karde dams' lake water. The third component shows relationships in release profiles suggest a delayed release of He – perhaps due to out + 2+ 2- the concentrations of Na , Ca , SO4 indicating the weathering of gassing from an organic or petroleum phase. evaporative minerals especially gypsum (CaSO4) and Glabuer's salt 1.2E-07 (Na2SO4) in the upper hand basin. In the classical plot of δ 18O vs δ 2H, the isotopic signature of lake 1.0E-07 water samples (-6.82‰, -48.3‰) plot further to (LMWL) comparing to the local ground water (-8.21‰, -57.5‰) and upstream river (- 8.0E-08 8.7‰,-61.8‰) which appear to be controlled by evaporation loss of 6.0E-08 2_485 Model the lake water. He (mol/L) 4.0E-08 2_485 Measured 2.0E-08 References [1] Cioni et al. (2002) Volcanology and geothermal research 120, 0.0E+00 0 20000 40000 60000 80000 100000 179-195. Time (sec) [2] Marini et al. (2000) Geochemica et Cosmochimica Acta, 64, 2617-2635. [3] Hong-jun et al. (2006) Enviromental science, 19, 689-695. Figure 1. Example of He out diffusion showing measured He concentrations in the stainless steel container head space (open squares) -11 2 and simulated out-diffusion profile indicating Dp = 3.2 × 10 m /s.

Mineralogical Magazine | www.minersoc.org 2123 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Paleo-environmental reconstruction Cave sediments as repositories of very of mercury and terrigenous organic old fossil invertebrates 1* 1 OANA T. MOLDOVAN , SILVIU CONSTANTIN , IOANA N. matter dynamics in large Northern 1 2 1 MELEG , LADISLAV MIKO , LAURA EPURE , CRISTIAN 3 3 4 Quebec boreal lakes: an assessment PANAIOTU , RELU ROBAN , AND ANDREJ MIHEVC of anthropogenic activities occuring 1* ”E. Racovitza” Institute of Speleology, Cluj, Romania, in their watersheds [email protected] 2European Commission, Bruxelles, Belgium, 1 1 1 MATTHIEU MOINGT *, MARC LUCOTTE , SERGE PAQUET , AND [email protected] 1 BASSAM GHALEB 3University of Bucharest, Bucuresti, Romania, [email protected] 1GEOTOP-UQAM, Montréal, H3C 3P8, Canada 4Karst Research Institute, Postojna, Slovenia, [email protected] [email protected] (* presenting author)

[email protected] Introduction [email protected] Cave sediments preserve the geological and paleoenvironmental [email protected] past as well as biological and anthropological information, important for the terrestrial continental history, where correlative sediments Mercury dynamics in boreal lakes is of special concern as human are mostly missing [1]. Our studies are first attempts to use fossil populations may be exposed to the contaminant through fish invertebrates from cave sediments as proxy in paleoclimate studies. consumption.To evaluate the impact of watershed pertubations on Microbiological studies have been added to explain the processes of the mercury dynamics in boreal aquatic systems, we studied sediment preservation. cores retrieved in six large boreal lakes of Québec (Canada) with Results Six caves (S-E Europe) provided fossil invertebrates, mostly watersheds disturbed by anthropogenic activities such as logging or mites, springtails and ostracods, originating from the surface mining activities, and in two undisturbed lakes chosen as reference environments. All these groups are excellent as paleoecological 210 lakes. Sediment rates were estimated by Pb dating and range from bioindicators and were identified in Pliocene-Pleistocene sediments 0.03 to 0.33 cm/yr. Total mercury (THg) contents and lignin (Fig. 1). Their presence has been correlated with other proxies and biomarkers (refering to both quantity and quality of terrestrial provided reliable information about the type of vegetation on the organic matter (TOM)) were measured in all eight cores whereas surface and the deposition condition inside caves. Microorganisms isolated from the sediments were extremely scarce, with differences watershed modifications over a 30 year period were determined by in the amount of bacteria or fungi. analysis of remotely sensed images using GIS. In all cores, THg

concentrations significantly increased over recent years with

maximum values comprised between 70 and 370 ng/g, the lowest

THg contents being observed in reference lake cores. Anthropogenic

Sedimentary Enrichment Factor (ASEF) is comprised between 2 and

15 and surprisingly, not all the lakes with disturbed watersheds

present an ASEF superior to the value of 3.5 usually reported in the

literature [1]. Our results allowed us to emphasize the importance of

mean slope inclination, repartition of slopes in classes and vegetation

cover in the drainage area on Hg fluxes reaching lake sediments. Figure 1: Invertebrate fossils found in the studied caves. Results from this study suggest that in large boreal lakes ecosystems,

the size and the characteristics (e.g. nature of the vegetation cover, Conclusion mean slope) can promote the uptake of atmospheric Hg leading to The depositional mechanisms and the low intensity of enahanced presence of THg in sediments. Then, supplementary Hg biochemical processes can explain the relatively good state of transfers from the watershed to the aquatic systems due to preservation of old invertebrate remains both in the cave sediments anthropogenic activities (e.g. logging and mining activities) can be and Arctic lake sediments [2]. Considering the age of sediments, the masked in sedimentary profiles. This study also underlines the state of preservation is relatively good. This may suggests a importance of TOM as vector of Hg since sedimentary Hg combination of: (1) a relatively short and slow transport to the site enrichment appears proportional to the amount of TOM coming from of deposition, (2) a rapid burial, i.e. a high sedimentation rate, and the watershed. (3) subdued microbial and biochemical processes that could have

altered the entire organisms. The difference we found in the

concentration of bacteria or fungi, at different sediment levels, can [1] Lucotte et al. (1995) Water, Air, and Soil Pollution 80, 467-476. also be correlated with dry/wet periods [3] and the work is still in progress.

[1] Sasowsky & Mylroie (2004) Studies of Cave Sediments. Kluwer Academic. [2] Moldovan et al. (2011) Biogeosciences 8, 1825- 1837 [3] de Vries et al. (2012) Nature Climate Change, DOI: 10.1038/NCLIMATE1368

Mineralogical Magazine | www.minersoc.org 2124 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Investigation of coupled Comparison of three organic flow and geochemical reactions geochemical proxies for sea-surface at the pore scale temperatures in a four year sediment by direct numerical simulation trap record 1* 2 1 1,2* 2 S. MOLINS , C. SHEN , D. SILIN , GESINE MOLLENHAUER , ELEONORA ULIANA , ANDREAS 1 2 1,2 3 4 C.I. STEEFEL AND D. TREBOTICH BASSE , JUNG-HYUN KIM , OSCAR ROMERO , ENNO 2 1 2 SCHEFUß , JENS HEFTER AND GERHARD FISCHER 1Lawrence Berkeley National Laboratory, Earth Sciences Division, Berkeley, USA, [email protected] (* presenting author) 1Alfred-Wegener Institute, Bremerhaven, Germany, 2Lawrence Berkeley National Laboratory, Computational Research [email protected] (* presenting author) Division, Berkeley, USA 2Marum Center for Marine Environmental Research, Bremen, Germany Prediction of chemical fate and transport in subsurface environments 3Royal Netherlands Institute for Sea Research, Texel, the often relies on reaction rate constants applicable to each grid block of Netherlands continuum-scale numerical models. Typically, laboratory-determined 4University of Granada, Granada, Spain reaction rates are applicable to a scale smaller than that resolved by the continuum-scale models. Upscaling of these rates to a grid block is The most well-established organic-geochemical SST proxy K’ possible under certain conditions; otherwise, microscopic and index U 37 based on haptophyte produced long-chain ketones macroscopic scales need be considered simultaneously (e.g. [1], [2]). This (alkenones) has been shown to yield robust estimates of annual mean is often the case in carbon sequestration or remediation applications SSTs but may be more problematic in high productivity eastern where the subsurface geochemical system is driven to far-from- boundary upwelling areas. In the last decade, two types of new equilibrium conditions in relatively short time scales, which result in organic geochemical SST proxies, i.e., the TEX86 index based on short characteristic length scales. In addition, induced geochemical archaeal glycerol dialcyl glycerol tetraether (GDGTs) and two reactions such as mineral precipitation and dissolution can modify the indices based on long-chain diols derived from diatoms (DCI) and geometry and structure of porous media, which further affects the eustigmatophytes (LDI) have been proposed. Those proxies have macroscopic reactions rates. been suggested to be applicable in settings where the alkenones are Direct numerical simulation techniques in which the Navier-Stokes less reliable or absent. On the other hand, each of the new indices or Stokes equations are solved using conventional methods (e.g. finite has its own caveats. These include, but are not limited to: 1) the fact volume, differences) allow for incorporation of complex multicomponent that GDGT producing archaea thrive throughout the water column reaction networks into pore scale models. We employ pore scale and perhaps also in the sediment; 2) limited understanding of the modeling based on direct numerical simulation of flow and physiological role of the respective lipids in their precursor multicomponent reactive transport to investigate the two-way coupling organisms; 3) incomplete understanding of the export mechanismns between precipitation-dissolution reactions and flow. We focus on calcite responsible for the transport of lipids from the depth of production dissolution-precipitation as system of environmental relevance. We to the sediments; 4) concerns regarding differential degradation of observe that non-uniformity in the flow field at the pore scale decreases individual lipids. the overall reactivity of the system in equivalent continuum-scale Here we address several of these questions using sediment trap systems. The effect becomes more pronounced as the heterogeneity of samples collected at 1-2 week intervals between June 2003 and the reactive grain packing increases, particularly where the flow slows March 2007. The trap was moored off Cape Blanc in an area strongly K’ sufficiently such that the solution approaches equilibrium locally and the influenced by seasonal coastal upwelling. We measured U 37, average rate becomes transport-limited. TEX86, and the diol indices as well as concentrations and fluxes of Simulations show that dissolution and precipitation reactions affect the respective lipids. The results are compared with total, carbonate, the pore space non-uniformly. As a result, a simple porosity-permeability opal and organic matter fluxes as well as diatom abundances. For all correlation may be insufficient to describe the complexity of the indices, we observe pronounced seasonal cycles, while flux- reaction-induced pore space evolution. The relative magnitude of the weighted averages agree well with values measured in underlying K’ reaction rate constants affects the evolution of the permeability-porosity surface sediments. Reconstructed SSTs based on U 37 and TEX86 relationship. In dissolution simulations, fast reactions result in localized correspond generally well with satellite measured SSTs but reveal K’ effects and further evolution of permeability is relatively unaffected by that U 37 is more uncertain during periods of highest productivity. subsequent porosity increase. In contrast, slow reactions cause a less The DCI shows a well pronounced but reverse relationship with SST localized dissolution, with the result that the permeability increase is than originally proposed. Fluxes of all lipids are closely tied to total consistent with the porosity increment. fluxes, implying that ballasting is an important mechanism. Delays between observed and reconstructed SST maxima are within the [1] Battiato, Tartakovsky (2011), J. Contam. Hydrol., 120-121,18-26 expected range for alkenones and larger but similar for GDGTs and [2] Wood (2009) Adv. Water Resour., 32, 723–736. diols, implying that these lipids are predominantly exported as diatom-rich aggregates known to sink at lower velocities than carbonate containing aggregates. We find no evidence for substantial sub-surface export of GDGTs.

Mineralogical Magazine | www.minersoc.org 2125 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Investigating Silver Nanoparticle Targeting sites for exploration for Transport in Soil via Synchrotron X- precious metal mineralization in the Ray Microtomography Guanajuato district, Mexico using

1* 1 petrography and fluid inclusions IAN L. MOLNAR , DENIS M. O'CARROLL , JASON I. 1 2 * GERHARD AND CLINTON S. WILLSON D. MONCADA AND R.J. BODNAR 1 University of Western Ontario, London, Canada, [email protected] Department of Geosciences, Virginia Tech, Blacksburg, VA 24061 * ( presenting author) USA, [email protected] (*presenting author) 2 Louisiana State University, Baton Rouge, U.S.A., [email protected] The search for mineral deposits is a time consuming, risky and The rapidly increasing production and use of very expensive process. Any technique that can help the nanoparticles carries with it a risk of their release into the explorationist to quickly and inexpensively discriminate between areas with high potential for economic mineralization and those with subsurface environment, contaminating aquifers that are either used lower potential provides a competitive advantage to those applying for municipal drinking water or discharge into surface water bodies. the technology. In this study, we describe a technique based on To consider their risk, it is necessary to understand nanoparticles’ petrography of gangue minerals and fluid inclusion characteristics fate in the subsurface. However, nanoparticle transport in the that may be applied in exploration for precious metal deposits to identify targets from surface, drill holes and underground workings. subsurface environment remains poorly understood and developed The Guanajuato mining district in Mexico was discovered 1548. relationships are specific to the imposed experimental conditions This initial discovery was in the la Luz area with major northwest and particle type. This research aims to improve our ability to non- trending vein systems. The mining in the area has been continuous and recent exploration programs to search for new targets have been destructively measure pore-level concentrations and distribution of successful. Mineralization in veins show variability, from gold-rich nanoparticles in an effort to better understand the soil - nanoparticle to silver-rich, in going from west to east. Ore textures also vary and interactions and role of pore geometry. include void space that formed during multiple fissuring events, Synchrotron x-ray computed microtomography (SXCMT) banded quartz veins, vuggy quartz, lattice bladed calcite, lattice bladed calcite replaced by quartz, massive quartz veins and is widely used for imaging soil and rock cores and fluids occupying stockworks with adularia and sericite/illite. More than 200 samples their pore space. The high resolution, three-dimensional, quasi-real from nine veins representing all different styles of mineralization time datasets output by SXCMT are capable of accurately were collected from the La Luz system, and the mineral textures and quantifying silver nanoparticle concentrations within a porous fluid inclusion characteristics of each sample have been defined. In addition, each sample was assayed for Au, Ag, Cu, Pb, Zn, As and Sb. media. These datasets can provide valuable information about silver Some drill holes were assayed for 34 elements. nanoparticle distribution throughout the pore-network and even Samples from the La Luz system show a wide range in silica within each individual pore. This presentation will: outline an textures. The veins that have been studied show a range in textures, SXCMT method for imaging and quantifying aqueous silver including colloform, plumose and jigsaw texture, quartz that are all indicative of rapid precipitation, such as occurs when fluids boil. nanoparticle solutions in porous media, present and analyze and Other mineral phases, including illite, adularia and bladed calcite are number of time-lapse images of silver nanoparticles invading and also indicative of rapid growth in a hydrothermal system and are evacuating a variety of water saturated soil types and examine the characteristic of boiling systems. Because boiling is an effective role of intra and inter-pore geometry on nanoparticle transport and mechanism for precipitating gold and silver from hydrothermal fluids, the presence of mineral textures indicative of boiling is a deposition. desirable feature in exploration. In many samples, textural evidence

for boiling is supported by coexisting liquid-rich and vapor-rich fluid inclusions, or Fluid Inclusion Assemblages consisting of only vapor-rich inclusions, suggesting “flashing” of the hydrothermal fluids. Several traverses along outcrop on the surface and perpendicular to the veins show that samples collected from within 25 m of the main veins show increasing precious metal abundances that correlate with an increase in features that indicate boiling. Drill core samples show the same behavior, with evidence of boiling increasing within 0 to 5 m of where precious metal abundances increase. This approach helps to establish new targets for detail exploration. Importantly, textural and fluid inclusion evidence for boiling has been observed in the deepest levels of the La Luz system, suggesting that additional precious metal resources may occur beneath these levels.

Mineralogical Magazine | www.minersoc.org 2126 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Mineralogical and geochemical Isotopic fractionation of U(VI) during processes occurring in sulfide-rich reduction by sulphide 1* 1 tailings after 60 years of subaqueous NIKHIL MONGA , STEPHEN J. ROMANIELLO , 1,2 storage AND ARIEL D. ANBAR 1,2* 1 MICHAEL C. MONCUR , CAROL J. PTACEK , DAVID W. 1School of Earth and Space Exploration, Arizona State University, 1 1,3 1 BLOWES , MATHEW B.J. LINDSAY , AND JOHN L. JAMBOR Tempe, AZ, USA, [email protected] (* presenting author) 2 Department of Chemistry & Biochemistry, Arizona State 1Earth and Environmental Sciences, University of Waterloo, University, Tempe, AZ, USA, [email protected] Waterloo, ON, Canada [email protected] (* presenting

author) [email protected] , [email protected] Understanding isotopic fractionation of 238U/235U between 2Alberta Innovates-Technology Futures, Calgary, AB, Canada, soluble U(VI) and insoluble U(IV) is useful in various ways, from 3Present Address: Earth and Ocean Sciences, University of British undersanding the geochemistry of U to its use as a paleoredox Columbia, Vancouver, BC, Canada [email protected] proxy [1]. In the environment, deposits of uranium formed by low The oxidation of sulfide minerals in subaerial tailings deposits temperature redox processes (e.g. black shales, roll front deposits) generates acid and releases sulfate and metals to pore water. are observed to be isotopically heavy compared to the fluid from 238 235 Subaqueous disposal of tailings is a common method for limiting which they precipitated by 0.4-1.0‰ (e.g. the U/ U of the Black sulfide-mineral oxidation. Numerous short-term studies have Sea sediments is consistantly heavier than the overlying water demonstrated that shallow water covers are effective at limiting column) [1,2,3]. This idea is consistent with theoretical calculations 4+ 2+ oxygen diffusion to submerged tailings; however, long-term studies which predict that U should be heavier than UO2 by 1.3‰, are lacking. The former Sherritt-Gordon Zn-Cu mine, located in primarily due to nuclear volume effects [4,5]. Despite the Sherridon, Manitoba, Canada, deposited sulfide-rich tailings into prevelance of this effect in nature, it has been suprisingly difficult to Fox Lake during 1951. The tailings formed a number of small produce isotopically-heavy reduced U phases experimentally. Two exposed islands with the majority of material submerged underwater, independent studies have shown that the reduction of U(VI) using extending outward into the Lake. Exposed tailings were visually zero-valent Zn and Fe produces no isotopic fractionation [2,6]. In oxidized and submerged tailings commonly were overlain by experiments with two different cultures of U-reducing bacteria, naturally-established vegetation. Surface water, porewater and core researchers found that the reduced phase was isotopically light by samples were collected in 2001 and 2009 to examine long-term 0.31-0.34‰, opposite of observations in the environment. biogeochemistry of land-deposited tailings and the submerged Motivated by this discrepancy and reasoning that sulfide is a tailings under approximately 1 m of water. common and abundant reductant in environmental settings, we set up Mineralogical examination of the land-deposited tailings experiments to measure isotopic fractionation during abiotic U showed a well-defined, ochreous oxidation zone that extended from reduction by sulfide. We reduced a 4 ppm U(VI)-CO3 solution in the surface to about 40 cm depth. The interval from 40 to 60 cm was a presence of 2.1 mM sulfide and 4.11 mM bicarbonate, maintained at transitional or intermediate zone of much weaker oxidation, and at a pH of 6.8 using a TRIS/HCO3 buffer under a UHP He atmosphere depths >60 cm sulfide minerals in the tailings were not altered. In [7]. At regular time intervals, the solution containing the soluble contrast to the thickness of the oxidation zone in the land-based U(VI) and a suspended insoluble precipitate, presumably U(IV) in tailings, the equivalent zone in the submerged tailings extended the form of uraninite [7], was sampled using a syringe and rapidly <6 cm below the water-solids interface. Porewater collected from separated using syringe filtration. the land-based tailings was characterized by low pH, depleted Our initial results are well-described by a Rayleigh model and alkalinity and elevated concentrations of dissolved sulfate and indicate that the reduced uranium phase is lighter than the solution metals. Microbial communities within these tailings were dominated by 0.189±0.097‰ (α = 0.999811±0.000097, 2σ). This effect is by neutrophilic sulfur oxidizing bacteria. Conversely, the natural opposite that observed in nature but similar to results observed for colonization of vegetation over the subaqueous tailings resulted in U-reducing bacterial cultures. Since all laboratory experiments so the development of strong reducing conditions evident from far produce moderately light or unfractionated reduced U, it is circumneutral pH conditions, low concentrations of dissolved possible that isotopic equilibration of U(VI)֖U(IV) is not achieved 34 13 on laboratory timescales. Alternatively, the chemical details of the sulfate and metals, H2S production and strong δ SSO4 and δ SDIC fractionation indicating microbially-mediated (dissimilatory) sulfate lab experiments may differ from natural systems and theoretical reduction. Within the submerged tailings, secondary marcasite was models in some key respect. For example, U speciation may have a observed in the relic ochreous zone occurring as coatings on large effect, or other reactions, such as U adsorption, could occur. primary minerals. This observation indicates that, following a period of oxidation, metals were subsequently sequestered from solution in [1] Weyer et al. (2008) Geochim. Cosmochim. Acta 72, 345- this zone. This finding further emphasizes the influence of reducing 3595,1370–1375 [2] Stirling et al. (2007) Earth Planet. Sci. Lett. conditions and microbial activity on metal mobility within mine 264, 208-225. [3] Romaniello et al (2009) AGU Fall meeting tailings. Results from this study provide insight for the submergence 2009, abstract # V54C-06. [4] Bigeleisen (1996) J. Am. Chem. Soc. of sulfide-rich tailings under a shallow water cover as a viable 118, 3676-3680. [5] Abe et al (2008) J. Chem. Phys. 129, 164309. method for long-term storage. [6] Rademacher et al (2007) Environ. Sci. Technol. 2010, 44, 5927– 5933 [7] Hua et al.(2006) Environ. Sci. Technol 40 , 4666-4671

Mineralogical Magazine | www.minersoc.org 2127 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Growth of nanostructured calcite Compositional data analysis under hydrothermal conditions in to constrain the geochemical footprint presence of organic and inorganic of iron oxide copper-gold deposits 1* 2 selenium JEAN-FRANÇOIS MONTREUIL , LOUISE CORRIVEAU , AND 3 1* 1 1 ERIC GRUNSKY G. MONTES-HERNANDEZ , G. SARRET , R. HELLMANN , L. 1 1 CHARLET , F. RENARD 1Institut de la Recherche Scientifique –Eau-Terre-Environnement, [email protected] (* presenting author) 1Institut des Sciences de la Terre (ISTerre), OSUG/CNRS, UJF, BP 2Geological survey of Canada, Québec, 53X, 38041 Grenoble, France [email protected] 3 Abstract Geological Survey of Canada, Ottawa, [email protected] Selenium is an important trace metalloid, whose global cycle is controlled by fluid-rock interactions in the Earth’s upper crust, Introduction interactions with bio-molecules in soils and living systems, and Lithogeochemical analysis of alteration haloes is an important atmospheric transport in ashes. The cycling of selenium is often exploration vector towards hydrothermal ore deposits. Iron oxide intimately associated with carbonate phases, with Se being generally copper-gold (IOCG) systems display a systemic development of incorporated as an impurity in calcite crystals or adsorbed on hydrothermal alteration types from sodic, to calcic-iron, and high to carbonate nanoparticles. In order to better understand the interaction low temperature potassic-iron and potassic alteration paragenesis of aqueous selenium species with carbonates, we studied the precipitation of calcite under hydrothermal conditions (30-90°C, that indiscriminately replace host rocks at local and regional scales. 25-90 bar) in a CO2-H2O-Ca(OH)2 medium in the presence of Where intense and pervasive, alteration leads to complete and aqueous inorganic and organic selenium compounds. Aqueous systemic mineralogical, chemical and textural transformation of carbonation reactions in the presence of selenium at elevated precursor rocks, resulting geochemical composition for each temperatures and pressures, relevant for long-term CO2 alteration type is reproducible irrespective of the nature of the sequestration in reservoirs and other natural geological systems, original host. However the zoning in the alteration haloes and the have until now not been investigated to the best of our knowledge. Macroscopic measurements, Electron microscopy (FESEM and types of deposits formed vary as a function of unidirectional, TEM) and synchrotron X-ray absorption spectroscopy (XAS) were cyclical or non unidirectional evolution of the hydrothermal system used in a complementary manner to investigate kinetic effect of Se, [1]. To further the development of geochemical vectors to IOCG and crystal size, structural order (crystallinity), morphology of crystal affiliated deposits and orient exploration campaign in under- faces, crystal organization, and selenium speciation in the calcite explored settings, we document the geochemical signature of samples. XAS data analysis showed clear evidence for the hydrothermal alteration from the Great Bear magmatic zone (GBmz) incorporation of selenite oxyanion (SeO 2-) into the calcite crystal 3 IOCG systems through the application of compositional data structure. At low Se content (1.3 mg/g calcite), a single site was observed with Se surrounded by six Ca atoms, whereas additional analysis based on the log-ratio approach and principal component sites, probably corresponding to surface sorption sites, were found analysis (PCA). with increasing Se content. XAS also showed that seleno-L-cystine Results and Conclusions (Secys) was chemically fragmented during carbonation, and the solid PCA has enabled the characterisation of the geochemical phase contained elemental and oxidized Se, in hexagonal or signature of the diagnostic alteration types. When compared to the amorphous form depending on the experimental conditions, with a other IOCG alteration types defined in the preceding section, minor proportion of Se(IV). Moreover, FESEM and TEM potassic and potassic-iron alteration show relative enrichment in K, measurements revealed a very complex effect of Secys on the particle size and aggregation/agglomeration process, leading to the Al, Ba, Si, Rb, Zr, Ta, Nb, Th and U. In contrast, when compared with following calcite morphologies: rhombohedra, elongated the other alteration types, calcic-iron alteration exhibit relative rhombohedra (c-axis elongation), scalenohedra, star-like and shell- enrichment in Ca, Fe, Mn, Mg, Zn, Ni and Co. Sodic alteration is like crystal aggregates, and irregular calcite polycrystals. The relatively enriched in in Na, Sr and Zr compared to the other aggregates and irregular polycrystals, which we designate as alteration signatures. nanostructured calcite material, were constituted of nanometer- The observed compositional variations established for each sized calcite crystallites (<100nm). The star and shell-like crystal aggregates, which were observed only in the presence of Secys, may alteration type were thereafter portrayed in IOCG alteration indexes. be due to crystal growth in the presence of associated secondary Combined with the IOCG alteration vector to mineralization model, organic compounds due to a simultaneous chemical fragmentation the resulting IOCG alteration indexes led to the development of an of Secys. Overall, the results from this study show that selenium (of IOCG alteration discrimination diagram that provides a useful tool biotic or abiotic origin) can be integrated into the crystallographic to quickly evaluate if a geochemical composition is related to IOCG structure of calcite under hydrothermal conditions. This has –associated hydrothermal alteration. Plotting the alteration indexes relevance for geological processes in diverse environments, such as on the GBmz regional geology map further demonstrates that the hydrothermal systems along mid-ocean ridges, or underground IOCG alteration indexes can provide a framework for field reservoirs associated with massive injection of CO2 for long-term geological sequestration. For more details refer to Montes- evaluation of the potential fertility and maturity of the GBmz IOCG Hernandez et al. [1-3]. systems and ultimately vector to ore during exploration. [1] Montes-Hernandez et al. (2011) Chem. Geol. 290, 109-120. [2] Montes-Hernandez et al. (2009) J. Hazardous Mater. 166, 788- [1] Corriveau, Williams & Mumin (2010) GAC, Short Course 795. [3] Montes-Hernandez et al. (2008) Crystal Growth & Design. Notes, 20, 89-110 8, 2497-2504.

Mineralogical Magazine | www.minersoc.org 2128 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Electrical conductivity of serpentine Epitaxial garnet-muscovite fluids at subduction zone conditions interfaces: Molecular modelling

1,2* 2A 1* 2 3 MAINAK MOOKHERJEE , M. A. GEETH MANTHILAKE AND STEPHANIE J. MOORE , KATE WRIGHT , JULIAN D. GALE , 2B 4 NOBUYOSHI MIYAJIMA WILLIAM D. CARLSON 1Earth and Atmospheric Sciences, Cornell University, Ithaca, USA, 1The University of Texas at Austin, Austin, U.S.A., [email protected] (* presenting author) [email protected] (* presenting author) 2Bayerisches Geoinstitut, Bayreuth, Germany, 2Curtin University, Perth, Australia, [email protected] [email protected], 3Curtin Univeristy, Perth, Australia, [email protected] [email protected] 4The University of Texas at Austin, Austin, U.S.A., [email protected]

Owing to pervasive faults, sea water interacts with oceanic crusts and Introduction stabilizes a suite of layered hydrous silicate phases. As the oceanic Computer simulations of garnet-muscovite interfaces provide a crusts subducts, the hydrous phases are also dragged along with the means of assessing the importance of interfacial energetics to subduing slab. These hydrous phases have limited thermal stabilities epitaxial nucleation. Experiments and natural samples provide information about specific grain boundary orientations and their and they eventually dehydrate, releasing fluids. These fluids are less prevalence and invite speculation on the importance of particular buoyant and hence migrates upwards. The fluids interact with the orientations, but the determination of grain boundary energies from overlying mantle wedge. These released fluids rehydrates the mantle these data is difficult. Currently, there are few constraints on the wedge i.e., rehydrates peridotitic mantle and stabilizes serpentinite. interfacial energies of naturally occurring minerals and no studies From geophysical observations, the mantle wedges of subduction have focused on garnet, a mineral that is of great significance to the zone are characterized by low seismic velocities and electrical metamorphic community. Combining data on grain boundary resistivities. In order to asses the role of fluids and serpentine, we orientations from natural and experimental samples with molecular modelling that uses energy minimization allows for the have measured the electrical conductivity of natural serpentinites at determination of relative energies for naturally-occurring grain pressure (2 GPa) and temperatures (up to 1000 K) relevant to boundaries between garnet and muscovite. mantle wedge conditions. Among the two natural serpentinite sample investigated, one contained antigorite and traces of carbonate and the Methods other contained chrysotile and carbonate. We distinguish the various Force-field simulations are particularly well-suited to the task of polytypes of serpentine by careful analysis of the crystal structure calculating grain-boundary energies for a specific set of conditions; using transmission electron microscopy (TEM). The measured here the General Utility Lattice Program (GULP) simulation code is contuctivity of serpentinite (10-4 Sm-1) is higher than anhydrous employed for this purpose [1]. A 2-D periodic slab model is used to investigate muscovite-garnet interfaces. Here each phase is olivine (10-6 Sm-1) by two orders of magnidute at 1000 K. Upon represented by two regions: an interfacial region in which the atoms dehydration, serpentine releases fluids which were also measured in are fully relaxed, in contact with a second rigid region that our expreiment and showed a very high conductivity of the order of represents the underlying bulk material. The two unconstrained 10-2-100 Sm-1 range. This can easlily explain the high conductivities regions of garnet and muscovite are then placed in contact to create observed in many subduction zones. the interface, while the bulk regions are allowed to rigidly translate relative to each other in order to minimize the total energy. The total potential energy of this final configuration is compared to that of the two bulk structures and by dividing the difference between the two by the area of the interface, an interfacial energy is calculated. The parameters used to describe the energetics of the muscovite and garnet structures include Buckingham potentials, an oxygen core- shell spring constant, a three-body term to describe the O-Si-O bonding angle, and a Morse bond to describe the H-O bond [2,3].

Results Initial simulations indicate that a garnet slab six unit cells thick and a muscovite slab five unit cells thick are sufficient for simulating the (110)grt || (001)ms with [100]grt || [100]ms interface. Additional simulations reveal that certain surface terminations of the muscovite and garnet slabs create more stable surfaces to be used in the garnet- muscovite interface simulations. The stability of these surfaces may be a guide to determining the precise interfaces between garnet and muscovite in natural samples.

[1] Gale & Rohl (2003) Molecular Simulation 29, 291-341. [2] Steele et al. (2000) Geochimica et Cosmochimica Acta 64, 257- 262. [3] van Westrenen et al. (2000) Geochimica et Cosmochimica Acta 64, 1629-1639.

Mineralogical Magazine | www.minersoc.org 2129 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Characterization of dissolved organic Groundwater vulnerability to matter (DOM) from diverse oceanic climate change in high elevation environments by reverse osmosis and catchments of the Sierra Nevada electrodialysis JEAN E. MORAN1* , MICHAEL J. SINGLETON2, DARREN

HILLEGONDS2, GLENN SHAW3, MARTHA CONKLIN4, BRADLEY 1* 1 KENNETH MOPPER , JOHN R. HELMS , HONGMEI K. ESSER2 AND ATE VISSER2 CHEN1, NELSON GREEN2, ARON STUBBINS3, E. 1California State University East Bay, Hayward, CA, USA, MICHAEL PERDUE2, PATRICK G. HATCHER1, AND 1 [email protected] (* presenting author) JINGDONG MAO 2 Lawrence Livermore National Laboratory, Livermore, USA, [email protected] ; [email protected]; [email protected] 1 Old Dominion University, Department of Chemistry and [email protected] Biochemistry, 4402 Elkhorn Avenue, Norfolk, VA ,USA, 3Montana Bureau of Mines and Geology, Butte, USA, [email protected]* (presenting author) [email protected] 2 Georgia Institute of Technology, School of Earth and Atmospheric 4University of California Merced, Merced, USA, Science, 311 Ferst Drive, Atlanta, GA, USA, [email protected] [email protected] 3 Skidaway Institute of Oceanography, 10 Ocean Science Circle, Study Design Savannah, Georgia, USA, [email protected] Snowmelt is an important component of groundwater recharge in high elevation watersheds of the western United States. In these The oceans contain approximately 685 x 1015 g of dissolved watersheds, the predicted climate change impacts on snowmelt will organic carbon (DOC), a pool similar to current atmospheric CO2 of likely alter the amount and timing of groundwater recharge, which ~861 x 1015 g C, and is thus a major component of the global carbon may lead to reduced groundwater production, declining water tables, cycle. However, only a small fraction of marine DOM is readily and reduced baseflow to streams. identifiable. Determining the chemical nature of the remaining We apply dissolved noble gas tracers to answer questions about fraction of oceanic DOM has been impeded by the lack of efficient recharge location and aquifer residence times in two catchments of and non-fractionating methods of isolation/desalting. Here, reverse osmosis- electrodialysis (RO/ED) [1] was used for isolating a differing size in the northern Sierra Nevada. The Olympic Valley 2 representative DOM fraction (~75%) for analysis by advanced solid- near Lake Tahoe is a 22 km alpine catchment while the Upper state 13C- NMR, UV-vis spectroscopy and wet chemical techniques. Merced catchment has an area of 465 km2 and drains through Samples were obtained from biogeochemically diverse Yosemite Valley. In both valleys, deep, high capacity production environments; i.e., photobleached surface gyre, productive coastal wells located in the upper portion of the valley draw groundwater upwelled, oxygen minimum, deep Atlantic, and old deep Pacific from over much of the sediment thickness. These wells were waters. NMR spectral editing revealed new insights into sampled for tritium and dissolved noble gases in order to determine carbohydrate biodegradation, and preservation of carboxyl groups and condensed aromatic structures (deep sea samples). Quaternary recharge temperatures (used to esimate to recharge elevation), and anomeric carbons were identified as an important component of bio- tritium-helium groundwater ages. refractory carbohydrates. However, despite some differences, these diverse samples yielded remarkably similar DOM compositions. Results Our results support the 3-pool DOM model (labile, semi-labile, and Noble gas recharge temperatures point to the lower slopes of the refractory) [2]. Evidence of ‘background’ refractory carbon was seen mountains, just above the valley floor, as important recharge areas for throughout the ocean DOM samples, and the high carboxyl signal in both catchments. Tritium-helium aquifer residence times are the deep Pacific sample supports the hypothesis that a major fraction of the refractory pool consists of carboxylic-rich alicyclic somewhat greater in Yosemite Valley wells (10-28 years) than in molecules (CRAM) [3]. Olympic Valley wells (<1-23 years), but in both areas the results RO/ED appears to be the most promising method to date for indicate relatively rapid turnover of groundwater in the coarse DOM isolation from seawater; as it can isolate up to 95% of marine alluvium of the upper valley reaches. The much larger Upper Merced DOM (average 75%; compared to 15-40% for other methods) and catchment thus supplies only somewhat greater buffering to the extracted DOM has properties closely resembling the perturbations in recharge and runoff that would be expected due to unextracted DOM [1,4]. As the method is capable of processing warmer temperatures. Using the information gathered from these large volumes of seawater, it can potentially be used to collect marine DOM reference material from different oceanic tracers, differing scenarios characterized by earlier snowpack melting environments, which currently do not exist and would be useful for and a higher proportion of precipitation as rain are evaluated with comparison to terrestrial DOM reference materials. regard to potential impacts to recharge.

[1] Koprivnjak et al. (2009). Geochim. Cosmochim. Acta 73, 4215- 4231. [2] Hansell& Carlson (2001) Oceanogr. 14, 41-49. [3] Hertkorn et al. (2006) Geochim. Cosmochim. Acta 70, 2990-3010. [4] Mopper et al. (2007) Chem. Review 107, 419-442.

Mineralogical Magazine | www.minersoc.org 2130 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Dynamical and chemical modeling of Interaction between Eu(III), phenolic terrestrial planet accretion acids and Al2O3 nanoparticles. 1* 2 1* 1 ALESSANDRO MORBIDELLI , DAVID C. RUBIE PAULINE MOREAU , SONIA COLETTE-MAATOUK , PASCAL E. REILLER1, ELISABETH GIBERT-BRUNET2 AND PIERRE GAREIL3 1Observatoire de la Cote d’Azur, Nice, France, [email protected] (*presenting author) 1 Commissariat à l’Energie Atomique et aux Energies Alternatives, 2Bayerisches Geoinstitut, Bayreuth, Germany, dave.rubie@uni- DEN/DANS/DPC/SEARS/LANIE, Gif-sur-Yvette , France, bayreuth.de [email protected] 2 Direction Générale de l’Armement, Bagneux, France, The “Grand Tack” dynamical model [email protected] The classic dynamical models of terrestrial planet formation, 3 Chimie ParisTech, Laboratory of Physicochemistry of Electrolytes, starting from a disk of planetesimals extended from the Sun to the Colloids and Analytical Sciences Paris, France, pierre- current orbit of Jupiter, typically produce in ~ 100 Ma a few planets [email protected] in the terrestrial zone on orbits comparable to the real ones [1], but the synthetic planets located near 1.5 AU are systematically more Introduction massive than Mars. The large Earth/Mars mass ratio seems to Natural colloid-borne transport of metal ions in ground water is require a strong depletion of solid mass beyond ~1 AU [2]. The known to occur. The implications of this kind of transport are “Grand Tack” model [3] explains such a depletion by coupling the especially important in the context of radionuclide migration in early orbital migration of the giant planets with the terrestrial subsurface water to evaluate risks of pollutants migration in planets accretion process. More precisely, the model assumes that, contaminated soils [1,2]. Furthermore, dissolved organic matter plays when the giant planets formed in a proto-planetary disk still a crucial role on metal ions transport. In particular, phenolic acids, dominated by gas, Jupiter first migrated towards the Sun and then, as resulting from lignin degradation, may be involved in the process of a consequence of the formation of Saturn, reversed its migration and metal ion adsorption onto mineral nanoparticles, as it is the case for spiralled outwards. This possibility is supported by hydro-dynamical aliphatic acids [3]. Our aim is to investigate the sorption of Eu(III) simulations [4]. If the reversal (or tack) of Jupiter’s migration (rare earth and analogue of trivalent actinides) onto Al2O3 occurred when the planet was at ~ 1.5 AU, the region beyond 1 AU nanoparticles in the presence of a hydroxybenzoic acid series (4- would have been strongly depleted by the passage of Jupiter. The hydroxybenzoic, 3,4-dihydroxybenzoic, and 3,4,5-trihydroxybenzoic simulations in [3] show that this model is consistent with the acids). existence and the structure of the asteroid belt between 2 and 4 AU, Results it produces in 30-50 Ma terrestrial planets on orbits consistent with First, the binary systems were characterized. Eu(III) was shown the real ones and, in particular, it explains why Mars is 10 times to have a high sorption capacity on our Al2O3 sample, as already smaller than the Earth and formed 10 times faster [5]. Thus, the described elsewhere [4,5]. Combining sorption data analysis with Grand Tack model is so far the most successful model of terrestrial time-resolved luminescence spectroscopy (TRLS) for Eu(III), at least planet formation from the dynamical point of view. 2 sorption sites of different energies were evidenced, as in Rabung et al. [5]. Complexation constants between Eu(III) and acids were Chemical modelling determined using TRLS. It appears that the complexation constant To test the Grand Tack model further, we are now applying increases from log10K° = 2.1 to 5.3 with the number of phenoxy geochemical constraints. The model is consistent with the delivery groups on the benzoic ring. As expected, the sorption isotherms of the of 2000 ppm of water to the Earth from planetesimals of chondritic Al 2O3-phenolic acid binary systems show different sorption composition, which agrees with recent estimates of the Earth’s capacities that cannot be explained by the hydrophobicity of the acids water budget and its isotopic composition [6]. Moreover, we are Indeed 4-hydroxybenzoic acid, which is the most hydrophobic modeling core-mantle differentiation [7] using the accretion history compound of the series, has the lowest sorption capacity on Al2O3. of the planets obtained in the Grand Tack simulations. Assuming that These results are consistent with published data, demonstrating that the material originally inside a1.5 AU had a reduced composition increasing the number of phenoxy groups on the benzoic ring of and that beyond this threshold was oxidized, our chemical models analogue compounds increases sorption on alumina [6]. Besides, the result in a FeO content of 8 wt% for the Earth’s mantle and a18 sorption isotherm of 3,4,5-trihydroxybenzoic acid at pH 5 can only be wt% for the Martian mantle, results that are consistent with observed fitted using sequential Langmuir isotherms, which evidences different concentrations [8,9]. In the future we will extend our analysis to sorption sites for this acid on Al2O3. include more elements (e.g. sulphur, volatile elements, HSEs and The same strategy was applied to study the ternary systems. Sorption water) and we will use more than two initial bulk compositions for isotherms were obtained as well as the TRLS spectra which permit to accreting material. discuss the pertinency of mixed-surface complexes that involves [1] Raymond et al. (2009) Icarus 203, 644-662. [2] Hansen (2009) Eu(III), hydroxybenzoic acids and aluminol sites. ApJ 703, 1131-1140. [3] Walsh et al. (2011) Nature 475, 206-209. References [4] Pierens & Raymond (2011) A&A 533, A131. [5] Dauphas & 1 Kersting et al. (1999) Nature 397, 56-59. Pourmand (2011) Nature 473, 489-492. [6] Marty (2012) EPSL 2 Utsunomiya et al. (2009) Environ. Sci. Technol. 43, 1293-1298. 313, 56-66. [7] Rubie et al. (2011) EPSL 301, 31-42. [8] Palme & 3 Alliot et al. (2006) J. Colloid Interface Sci., 298, 573-581 O'Neill (2003) In: Treatise on Geochemistry v 2, 1-38. [9] Dreibus 4 Janot et al. (2011) Environ. Sci. Technol. 45, 3224-3230. & Wanke (1985) Meteoritics 20, 367-381. 5 Rabung et al. (2000) Radiochim. Acta. 88, 711-716 6 Hidber et al. (1996) J. Eur. Ceram. Soc., 17, 239-249

Mineralogical Magazine | www.minersoc.org 2131 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Role of weak complexing agents in The amphoteric behaviour of water in metal uptake by phytoplankton silicate melts: Raman observations

FRANÇOIS M.M. MOREL*, LUDMILLA ARISTILDE, and physico-chemical description

* 1,2,* 3 AND YAN XU ROBERTO MORETTI , CHARLES LE LOSQ , DANIEL 3 R. NEUVILLE Princeton University, Department of Geosciences, [email protected] (* presenting author) 1 Dipartimento di Ingegneria Civile, Seconda Università di Napoli, Italia, [email protected] (*presenting author) The presence of weak ligands enhances the bioavailability of 2 Istituto Nazionale di Geofisica e Vulcanologia, Napoli, Italia, metals bound to strong chelating agents. For example, addition of [email protected] 3 cysteine (Cys) to EDTA-buffered media increases the rate of uptake Géochimie&Cosmochimie, IPGP, Paris, France, [email protected] [email protected] of zinc (Zn) by model phytoplankton. Such enhancement of uptake may result from 1) specific uptake of the Zn-Cys complexes, 2) Water plays a fundamental role in the dynamics and evolution of magmas in the deep interior and during volcano eruption. However, alleviation of diffusion limitation by dissociation of the complexes water speciation in silicate melts is not fully understood, despite in the boundary layer of the cells, or 3) exchange of Zn with uptake Infrared, Raman and NMR spectroscopy had provided some valuable

ligands, X, via formation of a ternary complex X-Zn-Cys. information about the H2O/OH speciation and its variations as a Mechanism 1 is ruled out by the facts that L- and D- isomers of Cys function of temperature, pressure, and water contents of melts. Some issues still remain unsolved about OH and H2O linkages to the are equally effective at enhancing the Zn uptake rate and that weak silicate network and we lack a general physico-chemical description ligand addition increases rather than decreases uptake in the absence of acid-base exchanges of water in melts. This includes the of EDTA. Mechanism 2 does not explain the effect of weak ligands, amphoteric behavior displayed by the water component into depolymerized glasses and melts. for this effect is seen when diffusion does not limit uptake of the By adopting a Raman-spectroscopy calibration of water free metal. The enhancement of Zn uptake kinetics by weak ligands dissolved in aluminosilicate melts [1], we studied the Raman OH- under various conditions is consistent with mechanism 3: i) stretching bands of hydrous glasses. OH-stretching Raman band records the vibrations of OH groups in molecular water or enhancement of uptake is particularly effective in Zn-deplete cells differently linked to the glass structure or metal cations. To whose high affinity transport molecules should be most able to constrain more in detail the evolution of such bands, we performed a exchange Zn with external ligands; ii) a variety of weak ligands have set of in situ experiments on rhyolite, basalt and albite glasses using similar effects on uptake, showing that the mechanism is relatively a micro-furnace at ambient atmosphere. We observed new high- temperature Raman features near 3650-3700 cm-1, and also changes non-specific; and iii) ligands that bind Zn in complexes that make the of water speciation that occurred below glass transition while formation of a ternary complex difficult do not increase Zn uptake. quenching to room temperature. Our results will be used to When essential metals are bound to strong chelating agents in constrain the acid-base exchanges occurring in melts and give insights into the relations between water and silicate network in natural waters, binding to weak complexing agents may increase melts. their bioavailability to ambient microorganisms.

[1] Le Losq, C., Neuville, D. R., Moretti, R., Roux, J., 2012. Determination of Water Content in Silicate Glasses using Raman Spectrometry: implications for the study of explosive volcanism. American Mineralogist, in press.

Mineralogical Magazine | www.minersoc.org 2132 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts The cataclysmic Campanian Geochemical signature of an injection Ignimbrite eruption (Campi Flegrei, complex in the deep middle crust

Southern Italy): Volatile melt-fining SAMUEL MORFIN1*, EDWARD SAWYER1 AND DANIEL BANDYAYERA2 processes and the effects of physico- 1Université du Québec À Chicoutimi, Sciences Appliquées chemical heterogeneities 2Bureau de l’Exploration géologique du Québec [email protected] (* presenting author) 1,2 2 3 4,2 R. MORETTI , I. ARIENZO , F. BRUN , L. CIVETTA , M. [email protected] 5,2 6 2 6 D’ANTONIO , C. LE LOSQ , L. MANCINI , D.R. NEUVILLE , [email protected] 2 G. ORSI , Introduction 1 Dip. Ing. Civile, Seconda Univ. Napoli, Italy (*presenting author) Upward transfer of anatectic magma from its lower crustal source is 2Istituto Nazionale di Geofisica e Vulcanologia, Napoli, Italy. the mechanism of crustal differentiation [1][2]. Recently, it has become 3Dip. Scienze Fisiche, Univ.Napoli “Federico II”, Italy. evident that a large proportion of anatectic magma does not reach the 4Dip. Scienze della Terra, Univ.Napoli “Federico II”, Italy. brittle/ductile transition depth. Field studies show that in the granulitic 5Géochimie&Cosmochimie, IPGP, Paris, France crust, anatectic magma is mostly transported in a pervasive network of narrow veins. Consequently, the upward migration of magma is arrested at, 6Sincrotrone Trieste S.C.p.A., Basovizza (TS), Italy. or close to, the level of the granite solidus and much leucogranite is accumulated at the granulite/amphibolite transition in the form of an 3 The late Pleistocene trachytic Campanian Ignimbrite (CI; 300 km injection complex [3]. This changes our perspective on the overall process DRE) covers the Campanian Plain near Naples, and is found behind of chemical differentiation of the crust ridges more than 1,000 m high at 80 km from source, the Campi Method Flegrei caldera (CFc). Very dilute pyroclastic density currents Since the formation of an injection complex is mostly controlled by the suggest a magma reservoir highly enriched in volatiles. Volatile depth of the solidus, which changes over the time span of a regional concentration, H2O particularly, exceeds significantly that of other metamorphic event, it is expected that at a single crustal depth explosive CFc eruptions. To understand such an enrichment and leucogranites should show a wide degree of chemical evolution. come out with a significant budget of discharged volatiles, Results particularly H2O, we analyzed products from the different eruptive Both major and trace elements indicate that the Opinaca Injection phases. Together with FTIR analyses on melt inclusions (MIs), we Complex (Québec) contains a continuum of leucogranite compositions also characterized pumice glasses for their water content by ranging from cumulate to highly fractionated (Fig. 1). adopting Raman spectroscopy. CI pumices display high values of porosity (> 60%, but typically > 70%), usually determined by density measurements on bulk samples. However, microscale analyses (2D and 3D) of natural pumices show a significant variability of porosity and permeability within samples. Such a variability may encompass up to 50% of porosity and contrasts with the typical values inherited by pumices at magma fragmentation. This variability is too often overlooked in the pertinent literature and ascribed to local effects within the large-scale dynamics occurring at the moment of the volcanic explosion and leading to generation of Plinian columns. Therefore, we also characterized, at the same micrometric scale of Raman investigations, pumice structure by Figure 1: Na O+CaO vs K O plot showing that (1) the variety of means of conventional X-ray PCT tomography at the Elettra 2 2 fractionation degree in the Opinaca is similar to deeper crustal levels synchrotron facility in Trieste (Italy). Data substantiate a model in (Ashuanipi Subprovince) with (2) a greater proportion of evolved which water accumulation in the CI magma chamber is made compositions although less evolved than higher crustal levels leucogranites possible by a melt fining process, similar to chromatographic (Quetico Subprovince). separation, that occurs over a time scale comparable to that of Conclusion magma residence time. This process produced extensive gas fluxing Development of injection complex in the deep middle crust result in within the magma chamber, leading to an overpressurized CO2- the accumulation of large volumes of leucogranites of various degrees of 3 dominated gas cap (about 150 km ), uniformly distributed at the top evolution close to the granite solidus depth. Evolved granites are thus not of the magma chamber. The main features of the magmatic only concentrated in the upper crust, many remain in the deep middle crust. “chromatographic” column can be retrieved by our joint Raman and Crustal differentiation is thus not as efficient as presently thought both in synchrotron X-Ray PCT approach, that allowed investigating the terms of volume and chemical distribution. Consequences of these changes effects of water exsolution and the structural changes in the should be considered into future crustal scale models (e.g. presence of polymeric network of the pre-fragmentation melt (quenched in the water, heat distribution). pumice glass). [1] Sawyer et al. (2011) Elements 7, 229-234. [2] Brown et al. (2011) Elements 7, 261-266. [3] Morfin et al. (submitted) Lithos.

Mineralogical Magazine | www.minersoc.org 2133 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Evidence for Mo, organic molecule, Redox reactions affecting arsenic at and mineral interactions iron-(oxyhydr)oxide mineral surfaces 1 1 1 1* 1 CAITLIN M. CARNEY , JOHN P. LISHER , KELLY A. MURPHY , GUILLAUME MORIN , GEORGES ONA-NGUEMA , KARIM 1 1 1 1 1 PHILLIP R. SLOGOFF-SEVILLA , ANTHONY D. WISHARD , AND BENZERARA , FARID JUILLOT , YUHENG WANG , CLAUDIA 1* 2 2 2 JENNIFER L. MORFORD HOHMANN , MARTIN OBST , ANDREAS KAPPLER , GORDON 3 E. BROWN JR . 1Franklin & Marshall College, Department of Chemistry, [email protected] (*presenting author) 1Environmental Mineralogy, IMPMC, CNRS-UPMC, Paris, France. ([email protected]; * presenting author) Introduction 2Geomicrobiology, University of Tübingen, Germany. Molybdenum (Mo) is relatively conservative in oxic seawater 3Surface & Aqueous Geochemistry Group, Department of but is removed to the solid phase under sulfidic conditions. Geological and Environmental Sciences, Stanford University, Investigators have been encouraged to use Mo solid phase Stanford, CA, USA. concentrations or accumulation rates to infer past changes in reducing conditions in sediments and/or overlying waters. However, For the last few decades, a great deal of attention has been difficulties in fully using Mo as a proxy derive from a lack of focused on better understanding and predicting the fate of arsenic in information regarding the controlling factors for the removal of Mo the environment. Indeed, due to natural as well as anthropogenic from the aqueous phase to the solid phase. A commonly accepted inputs, this element has been recognized as a pollutant in several hypothesis involves the thiolation of molybdate to a form that is countries, with major impacts on human health. One of the main more easily scavenged by particles1,2. A subsequent hypothesis conclusions drawn from the numerous studies conducted on natural instead suggests that the precipitation of a nanoscale Fe(II)-Mo(VI) and laboratory systems is that nanometer-sized iron-(oxyhydr)oxide sulfide mineral dictates Mo removal from the aqueous phase3. minerals play a key role in the scavenging of arsenic in water, soils However, persuasive correlations between Mo concentrations and and sediments via sorption reactions. In addition, redox sulfurized organic matter hint at a role for organic molecules in Mo transformations of arsenic have been shown to greatly influence its fixation and preservation in sediments4. mobility and toxicity, with As(III) species generally more mobile We seek to clarify the influence of organic matter on Mo and toxic than As(V) species. Despite this extensive knowledge base, sequestration by determining the role of organic molecules, either important questions remain about the detailed mechanisms of aqueous or bound to solid surfaces, in the transition of Mo between particular As oxidation and reduction reactions in complex the aqueous and solid phases. Simple organic molecules and single heterogeneous media, and about the ultimate fate of this element in minerals are used as analogs for more complex humic material and the presence of various electron donors and acceptors [1-4]. heterogenous sediments, respectively, present in the environment. In the present communication, we will review important pathways for arsenic redox transformations that can be driven by Results either abiotic or abiotic processes. Examples will be chosen from Initial results suggest that the nature of the organic molecule recent studies using synchrotron-based X-ray absorption and the type of functional groups are important for aqueous specoscopy (XANES, EXAFS) to monitor the redox state of arsenic molybdate-organic interactions. Molybdate preferentially in natural and laboratory systems. Focus will first be given to redox complexes with organic molecules that have two phenolic functional transformations that are usually slow at room temperature, but which groups on adjacent carbons as seen using 1H and 13C NMR. Analysis can be catalyzed by chemical and physical factors. Particular of molybdate with either 1,2-dihydroxybenzene or 2- attention will be paid to the complex interplay between Fe(II)/Fe(III) mercaptopropionic acid using UV/Vis and ESMS supports the and As(III)/As(V) redox couples in the presence or absence of formation of a 1:2 Mo:organic complex. oxygen, and the role of photocatalysis in redox reactions [1-4]. Molybdate adsorption to aluminum oxide or pyrite is pH Regarding these processes, classical artifacts involving catalysis of dependent with greater adsorption under acidic conditions. All redox reactions during exposure to synchrotron radiation will be adsorption experiments are consistent with a one-site adsorption discussed as possible indicators of light-induced reactions. surface as modelled with a Langmuir isotherm. The addition of 2- In addition, examples of biotic redox transformations able to mercaptopropionic acid possibly inhibits the adsorption of contribute to As sequestration by oxidized [5-7] or reduced iron- molybdate to pyrite, although it is still uncertain whether the thiol containing minerals [8] will be discussed in relation to the differing competitively occupies pyrite adsorption sites or complexes affinities of As(III) and As(V) species for specific mineral surfaces molybdate, thereby making it incapable of adsorbing to the solid [9]. surface. Ultimately, the results of this research should clarify the [1] Charlet et al. (2011) CRGeosci. 343, 123-139. [2] Bandari et al. influence of organic matter on Mo sequestration in modern (2011) ES&T 45, 2783–2789. [3] Ona-Nguema G. et al. (2010) sediments. ES&T 44, 5416–5422. [4] Amstaetter et al. (2010) ES&T 44, 102- 108. [5] Benzerara et al. (2008) GCA 72, 3949-3963. [6] Hohmann [1] Helz et al. (1996) Geochim. Cosmochim. Acta 60, 3631-3642. et al. (2010) ES&T 44, 94-101. [7] Hohmann et al. (2011) GCA 75, [2] Bostick et al. (2003) Environ. Sci. Technol. 37, 285-291. [3] 4699-4712. [8] Ona-Nguema et al. (2009), GCA 73, 1359-1381. [9] Helz et al. (2011) Chem. Geol. 284, 323-332. [4] Tribovillard et al. Wang et al. (2010) ES&T 44, 109-115. (2004) Chem. Geol. 213, 385-401.

Mineralogical Magazine | www.minersoc.org 2134 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Geochemical composition of erosion Electron microprobe and LA-ICP- products in Central Nepal : contraints MS analyses of ilmenite from lunar on landslide and soil erosion samples 1* 2 processes. CAROLINE-EMMANUELLE MORISSET ,SIMON JACKSON , 2 1 1* 1 MARIE-CLAUDE WILLIAMSON ,VICTORIA HIPKIN AND GUILLAUME P. MORIN , CHRISTIAN FRANCE-LANORD , 3 1 1 1 KIMBERLY TAIT MAARTEN LUPKER , FLORIAN GALLO , JÉRÔME LAVÉ , 2 ANANTA PRASSAD GAJUREL 1Canadian Space Agency, Saint-Hubert, Canada, (* presenting author: [email protected]), 1 CRPG-CNRS, 15 rue Notre-Dame-des-Pauvres, 54501, [email protected] Vandoeuvre-les-Nancy, France 2Geological Survey of Canada, Ottawa, Canada, [email protected] (* presenting author ) [email protected], 2Department of Geology, Tribhuvan University, Kathmandu, Nepal [email protected]

3Royal Ontario Museum, Toronto, Canada, [email protected] In order to interpret continental sedimentary archives in terms of erosion processes in the past, we made an effort to characterise Oxygen can be liberated from ilmenite at lower temperature than actual landslides and soils geochemical signatures, in order to trace these processes in the river suspended load (SL) throughout a from silicates present in the lunar regolith, making ilmenite a key monsoon season. resource for human settlement on the Moon. Major and trace element To assess this question, daily monitoring of SL chemistry have concentrations of ilmenite contained in twelve samples selected from been conducted during 2010 monsoon in two watersheds : the the six Apollo landing sites (10 basalts, one impact melt, and one Narayani river that drains whole central Nepal and the Khudi khola, impact breccia) and in one lunar meteorite (NEA 001) have been one of its minor High Himalayan tributaries. In addition, systematic determined using electron microprobe and LA-ICP-MS. These sampling was conducted on hillslopes material from soils and analyses help us to understand the role of ilmenite in the landslides in Khudi. This catchment was chosen because it crystallization of magma on the Moon and to determine if the represents typical South flank Himalayan basin exposed to severe ilmenite from different rock types has a specific chemical signature. precipitations (3.5 m/yr), and undergoes intense erosion rates as Ilmenite can reach a modal proportion of up to 20% in basaltic rocks. high as 2-3 mm/yr [1]. Characteristics of this watershed are : 800 to Some ilmenite grains contain rutile, Cr-spinel and baddeleyite 4500 m elevation, 152 km2, dense forest cover up to 3500 m, and active landslide erosion for at least one decade. needles. The TiO2 in the analyzed ilmenite from the Apollo samples Source rocks, soil and landslide samples are compared to river varies from 52.4 to 55.9 wt% while it is noticeably lower in the suspended sediment using mobile to immobile element ratios. Data meteorite sample (i.e. 51.7 to 52.8 wt%). In all samples, FeO varies clearly show that soil material has undergone weathering with loss from 37.4 to 46.7 wt% and MgO from 0.1 to 5.1 wt% except in the of Na, K and Ca relative to average source rocks. In contrast, impact melt where it is higher (5.3-5.7 wt%). The largest variation landslide products and suspended sediments have close chemical observed in MgO within an ilmenite grain is of 0.3 wt% (e.g. 4.7-5.0 signature and are only slightly depleted relative to source rocks. MgO wt%), implying that the observed variation between grains Geochemical composition of the Narayani SL have similar cannot be attributed to mineral zoning. So far, three basaltic samples characteristics suggesting that even at large scale the erosion is have been analyzed by LA-ICP-MS. Cr varies from 1080 to 7580 dominated by physical erosion processes rather than by progressive ppm, V varies from 80 to 453 ppm and both elements are positively soil development. correlated with MgO. Zr (123-2330ppm) and Hf (5.95-85 ppm) The results of this study show that chemical composition of SL concentrations are highest in the baddeleyite-bearing ilmenite grains. are close to those of pristine source rocks, and contrasted with those of soil products. Therefore, active and steep reliefs are mostly Nb (20-107 ppm) and Ta (1.85-8.52 ppm) are positively correlated eroded through landsliding rather than through soil erosion. The later but are not well correlated with Zr or Hf. REE patterns show is difficult to quantify using SL composition in spite of enhanced enrichment in HREE (CeN/LuN: 0.0001-0.005) with a strong negative soil erosion by agricultural activity [2-3] that is significant in the Eu anomaly (Eu/Eu* from 0.003 to 0.413). The ratio of MgO vs

Narayani Basin. TiO2 of the ilmenite permit discrimination of what type of sample the ilmenite is from. Ilmenite from the basaltic samples form a trend [1] Gabet et al. (2008) Earth and Planetary Science Letters 267, 2 (n=355; slope=1.89; r =0.86) that is richer in TiO2 for the same MgO 482–494. [2] Gautam et al. (2003) Agriculture, Ecosystems & 2 Environment 99, 83–96. [3] Merz (2004) ICIMOD Institute of than the impact breccias (n=11; slope=1.5; r =0.91) and the Geography, University of Berne, Switzerland. meteorite (n=10; slope=4.38; r2=0.42) samples. LA-ICP-MS analysis of the remaining samples will permit evaluation of whether the observed geochemical distinctions between the three sample groups are identifiable using trace elements.

Mineralogical Magazine | www.minersoc.org 2135 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Recovery and reproducibility of the Sourcing hydrocarbons at two conventional and accelerated solvent continental sites of present-day extraction methods for lipid biomarkers serpentinization: The Tablelands, NL, 1 2 3 ANJA MORITZ *, KARINE LALONDE , YVES GÉLINAS CAN and The Cedars, CA, USA 1 1 1 1Concordia University, Montreal QC, Canada, PENNY MORRILL , AMANDA RIETZE , NATALIE SZPONAR , 2 3 [email protected] (*presenting author) J.GIJS KUENEN ,SHINO SUZUKI-ISHII , AND KENNETH H. 3 2Concordia University, Montreal QC, Canada, NEALSON . [email protected] 1 Dept. Earth Sciences, Memorial University of Newfoundland, NL, 3Concordia University, Montreal QC, Canada, CAN, [email protected] (* presenting author) [email protected] 2 Delft University of Technology, Delft, Netherlands 3 J. Craig Venter Institute, San Diego, CA, USA

Abstract The hydration of ultramafic rocks, via the serpentinization Biomarkers are widely used as tracers of the processes reaction, is a suspected source of putative hydrocarbons (methane affecting organic matter cycling in the environment. Lipids, or more and possibility higher molecular weight gases hydrocarbons) on specifically hydrocarbons, sterols and fatty acids, are used Mars. On Earth, serpentinization produces hydrogen gas and the extensively as indicators of the sources of organic matter as well as reducing conditions necessary for abiogenic hydrocarbon synthesis, its alteration by photochemical or microbial degradation. The while also producing conditions amenable for chemolithotrophic extraction of these lipids from sediments consists in a liquid-solid life. Additionally, on Earth, continental sites of serpentinization are extraction using a mixture of non-polar solvents (most often often assoicated with buried sedimentary organic matter (SOM) that dichloromethane and methanol). Conventional extraction of lipids can possibly contribute thermogenic hydrocarbons to the ultra-basic from solid matrices traditionally involves ultrasonic extraction reducing springs associated with the serpentinization. This study combined with shaking, or Soxhlet-based solvent refluxing. These sources hydrocarbons from two continental sites (the Tablelands, two techniques are long and tedious and use low temperature and low NL, CAN and The Cedars, CA, USA) of present-day serpentinization pressure conditions to extract lipids. We recently found out that iron where methane and higher molecular weight hydrocarbons are oxides associate very intimately with sedimentary organic matter, present in the ultra-basic reducing springs discharging from altered leading to the preservation of labile organic material, likely through ultramafic rocks. covalent bonding [1]. Our results show that a fraction of the The Cedars was the first site to be described where ultramafic extractable lipids are not quantitatively recovered when using low rocks are undergoing present-day serpentinization at shallow depth temperature and low pressure methods for iron oxide-containing and low temperature. The Cedars is part of California’s Coast sediments. An extraction at high pressure and high temperature using Ranges and is a section of a peridotite body that was obducted as part an accelerated solvent extractor (ASE) disrupts these iron-organic of the Franciscan Subduction Complex (Late Cretaceous). matter structures, releasing the lipids into solution. The Conversely, the much older Tablelands Ophiolite, NL is part of the reproducibility and lipid recovery of the ultrasonication and ASE Bay of Island Ophiolite. The Tablelands Ophiolite is composed of methods will be presented and discussed. ultramafic rocks that were obducted onto the eastern edge of ancient

North America (Ordovician). Elevated concentrations of H2, CH4 and higher molecular weight hydrocarbons have been detected in the ultra-basic reducing springs discharging from The Cedars and the Tablelands. Our geochemical investigations show that the methane at

[1] Lalonde et al. (in press) Nature. The Cedars is primarily microbial in origin (for example C1/C2+ = 6000, δ13C = -68.0 ‰), while the methane sampled from the 13 Tablelands is not (for example C1/C2+ = 5, δ C = -26.3 ‰). However, the source of the higher molecular weight hydrocarbons 13 may differ from the source of methane (The Cedars average δ C C2- 13 C6 ~-23.6 ‰ and the Tablelands δ C C2-C6 ~-30.7‰). Both The Cedars and the Tablelands could have thermogenic and/or abiogenic hydrocarbons contributing to the hydrocarbons detected in the springs. The purpose of this study is to source the higher molecular weight hydrocarbons through the analyses of the hydrocarbons in the ultra-basic reducing springs and the SOM associated with the Ophiolite.

Mineralogical Magazine | www.minersoc.org 2136 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Microbial transformation of Critical zone weathering of glacial till radionuclides - the radionuclide in the Prairie Potholes Region: A biomineral interface. major control on wetland ecology 1 2 K. MORRIS1*, D. BROOKSHAW1, V. EVANS1, C. THORPE1, A. JEAN M. MORRISON *, MARTIN B. GOLDHABER , 1 1,2 1 1,2 2 2 WILLIAMSON , G. T. LAW , A. RIZOULIS , F.R. LIVENS AND CHRISTOPHER T. MILLS , KARL J. ELLEFSEN J.R. LLOYD1 1U.S. Geological Survey, Denver, United States, 1Research Centre for Radwaste and Decommissioning and [email protected] (* presenting author) Williamson Research Centre, and 2Centre for Radiochemistry 2U.S. Geological Survey, Denver, United States Research, The University of Manchester, Manchester, M13 9PL. (*correspondence: katherine.morris@ manchester.ac.uk) The Prairie Potholes Region (PPR), a vital ecosystem in North 2 America comprising a 715,000 km region in the north-central U.S. and south-central Canada, is characterized by millions of closed- Microbial processes can have a profound effect on the basin wetlands. Sulfate is the dominant anion in these wetlands. A solubility of radionuclides in natural and engineered thick oxidized brown (iron oxide-bearing) zone which transitions to environments. The scope of these processes is significant with unoxidzed, gray till has been widely reported in the PPR. clear evidence that radionuclide solubility may be altered The objective of this study is to characterize till alteration in the 92 hectare Cottonwood Lake Area (CWLA) near Jamestown, ND, enzymatically via mediated redox reactions, by indirect redox where Pleistocene-age glacial till overlies pyrite-rich marine shale. reactions with, for example, Fe(II)-bearing biominerals We studied the geochemistry and mineralogy of three cores drilled andfor non-redox active species, even by incorporation along a topographic gradient from an upland position (ground surface at 569 m) to the edge of a low lying discharge wetland reactions into neo-formed biominerals formed as (ground surface at 560 m) referred to as P1, whose anion content is 2- physicochemical conditions change. Understanding these dominated by SO4 . A brown-gray transition was recognized whose reactions is important across radionuclide impacted depth systematically decreased from 13.3 m in the upland core to environments from contaminated land environments where 7.3 m at the wetland edge. We also analyzed archived cutting samples from a groundwater well drilled in 1978 near the margin of bioreduction and biomineralisation processes may be wetland P1. This well penetrated to bedrock at 136 m and the harnessed to control radionuclide mobility, through nuclear brown-gray transition was observed at 12.3 m. facilities where biological processes are often poorly Semi-quantitative X-ray diffraction (XRD) analysis of material constrained yet may be critical in long term management and from the cores and cuttings detected gypsum in the brown zone that ranged from trace amounts to 8 wt % with the highest concentrations control of radionuclides, and finally to radioactive waste at or below the water table. Gypsum was below detection (<1 wt%) disposal scenarios where there is a paucity of information on in the samples from the gray zone. These results were confirmed by the influence of microbial processes on bio-mineralisation water leaches for soluble sulfates. Using a terrain conductivity meter, the electrical conductivities of subsurface were measured and radionuclide behaviour under geological disposal facility along a transect parallel to the core samples. The brown zone was conditions. more conductive than the gray zone (120-150 mS/m vs. <120 mS/m) Recent work exploring the behaviour of Sr, U and Np will be likely due to the presence of gypsym. Both XRD and quantative discussed with a focus on (bio)mineralisation, reduction and reductive dissolution assays showed that gray zone samples, including those from the deep well, contain pyrite in the range 0.3 to reoxidation reactions and their impact on radionuclide 1.1 wt %. behaviour. The products of biomineralisation in terms of bulk We conclude that shale-derived pyrite in the till has been slowly 2- element cycles and (bio)geochemistry will be discussed in the oxidized to SO4 , which is leached to groundwater and responsible context of radionuclide solubility. Studies relevant to a range for the consistently high content of S in the CWLA wetlands. These weathering processes drive groundwater and wetland geochemistry, of environments including radioactively contaminated land, resulting in dramatic variations in salinity over short distances nuclear legacy ponds, and high pH environments relevant to depending upon where individual wetlands reside in local environments expected in geological disposal of cementitious groundwater systems. Variations in wetland chemistry influence the waste forms will be discussed. The biogeochemical fate of flora and fauna that inhabit the wetlands. Therefore, understanding the long-term alteration processes in the till has a close link to radionuclides across these systems and in the sometimes wetland ecology in this region that is known as the duck factory of "extreme" environments that these systems pose will be North America. highlighted.

Mineralogical Magazine | www.minersoc.org 2137 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Structure and Energetics of Smectite Reconstructing a young martian Interlayer Hydration: Molecular history with igneous Dynamics Investigations of Na- and microbaddeleyite rimmed by Ca-Hectorite metamorphic zircon

1 2 1* 2 3 CHRISTIN P. MORROW *, A. ÖZGÜR YAZAYDIN , GEOFFREY M. D. E. MOSER , K.R. CHAMBERLAIN , K.T. TAIT , A.K. 3 4 5 4 1 3 1 BOWERS , ANDREY G. KALINICHEV , AND R. JAMES KIRKPATRICK SCHMITT , I. R. BARKER , B.C. HYDE , J. DARLING 1 Department of Chemistry, Michigan State University, East Lansing, MI, 1Western University, London, Canada, [email protected] USA, [email protected] (*presenting author) 2University of Wyoming, Laramie, U.S.A. 2 Department of Chemistry, Michigan State University, East Lansing, MI, 3Royal Ontario Museum, Toronto, Canada USA and Department of Chemical Engineering, University of Surrey, 4UCLA, Los Angeles CA, U.S.A. Guildford, UK, [email protected] 3Division of Chemistry and Department of Materials Engineering, Alfred A current paradox in martian geochronology is that University, Alfred, NY, USA, [email protected] basaltic shergottites yield whole rock and unradiogenic 4Department of Chemistry, Michigan State University, East Lansing, MI, mineral isotopic Pb-Pb compositions consistent with a USA and Laboratoire SUBATECH, Ecole des Mines de Nantes, primary Noachian (>4 Ga) age for crystallization whereas Nantes Cedex 3, France, [email protected] mineral isotopic analyses consistently return ‘young’ post- 5College of Natural Sciences, Michigan State University, East Lansing, Amazonian (<0.6 Ga) dates. To assess the significance of the MI, USA, [email protected] mineral dates, we have combined single-grain isotopic SIMS U-Pb microbaddeleyite dating with chemical and deformation Molecular-scale interactions present at mineral-water interfaces and in clay microstructure data obtained with electron nanobeam interlayer galleries control numerous environmental processes, including techniques (e.g. CL, EBSD) to resolve baddeleyite chemical interactions in soils and transport of nutrients and pollutants through them.[1-4] Understanding these processes requires accurate paragenesis and potential for isotopic disturbance by shock knowledge of the structure, energetics, and dynamics of the interaction processes. We have focused on microbaddeleyites from among the mineral substrate, ions, and water molecules.[5, 6] Challenges shergottite NWA 5298, an enriched basaltic shergottite to this objective include experimental difficulties in probing these exhibiting a primary phaneritic igneous texture which has interfaces and interlayers at the molecular scale; fully characterizing the similarities to other basaltic shergottites. The baddeleyites are mineral substrate; and identifying how the mineral surface, ions, and water molecules each contribute to the overall structure, energetics, and generally subhedral to euhedral blocky to bladed grains, 2 to dynamics of these systems.[6] Linked computational molecular dynamics 20 μm long, at the boundaries of larger main phase minerals. (MD) simulations and experimental nuclear magnetic resonance (NMR) SE and BSE imaging of grain interiors showed that grains are studies are particularly effective in addressing these issues.[7-9] often composed of equant microdomains that give the Here we focus on MD studies of Na- and Ca-smectite (hectorite) appearance of a granular texture. Grains are often surrounded interlayer galleries to provide a molecular-scale picture of the structure and dynamics of their hydration[9, 10] and to complement our earlier NMR by discontinuous rims of zircon a few microns wide identified investigations of these systems.[7-9] Classical MD simulations were by EDS and EBSD. CL zoning types in baddeleyite include undertaken in the NPT and NVT ensembles to determine the structural and simple bright, narrow rims of variable thickness surrounding energetic changes with increasing hydration with focus on the single- and dark cores, and patchy to diffuse and mottled CL domains at double-layer hydrates. The results show substantial changes in the the margins of grains or in areas of crystal disruption and hydration of the interlayer cations, the orientations of the water molecules, the hydrogen bond network involving the water molecules and basal apparent granular texture. A subset of grains exhibits oxygen atoms, and the resulting potential energies as the interlayer gallery oscillatory planar growth banding similar to that which we expands. have observed in terrestrial igneous baddeleyite. Our EBSD mapping indicates clearly that the baddeleyite is now quasi- [1] Scheidegger et al. (1996) Soil Science 161 813-831. [2] Stumm (1997) amorphous and is hosted by amorphous maskelyinite, Colloids and Surfaces A-Physicochemical and Engineering Aspects 120 whereas zircon is crystalline and apparently unshocked, 143-166. [3] O'Day (1999) Reviews of Geophysics 37 249-274. [4] Koretsky (2000) Journal of Hydrology 230 127-171. [5] Wang et al. although an investigation at higher resolution for the high (2001) Chemistry of Materials 13 145-150. [6] Wang et al. (2006) pressure polymorph, reidite, is ongoing. SIMS analysis of 12 Geochimica et Cosmochimica Acta 70 562-582. [7] Bowers et al. (2008) grains yielded 206Pb/238U dates ranging from 209 ± 22 Ma Journal of Physical Chemistry C 112 6430-6438. [8] Bowers et al. (2011) (2σ) to 26 ± 2 Ma. An unforced discordia line has an upper Journal of Physical Chemistry C 115 23395–23407. [9] Bowers et al. intercept with concordia at 0.9 +1.2/-0.7 Ga and a zero age (2012), unpublished. [10] Morrow et al. (2012) Journal of Physical Chemistry C, submitted. lower intercept. Our SIMS data together with microtextural data for the baddeleyites are consistent with U-Pb disturbance of primary, post-Noachian igneous crystals during shock, recent shock heating, and zircon growth. A scenario is favoured wherein bulk melting of ancient 4 Ga parent material produced the NWA 5298 source magma through volcanic or impact melting. This would reconcile ‘young’ mineral dates and isochrons with the unradiogenic and whole rock Pb-Pb age data from basaltic shergottites.

Mineralogical Magazine | www.minersoc.org 2138 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Remobilisation of uranium from In situ high pressure changes to the O contaminated sediments: effect of the K-edge electronic structure of bioturbation CaMgSi2O6: An x-ray Raman 1 2 MIKAEL MOTELICA-HEINO *, F.LE MOING , SANDRA approach 2 2 2 LAGAUZERE , JEAN-MARC BONZOM , LAURENINE FEVRIER 1* 2 3 4 3 B.J.A. MOULTON , M. KANZAKI , H. FUKUI , N. HIRAOKA AND VIRGINIE CHAPON 1 AND G.S. HENDERSON 1ISTO, University of Orléans, Orléans, France, 1 [email protected] University of Toronto, Toronto, Canada, 2IRSN, Cadarache, France, [email protected] [email protected]*; [email protected] 2 3CEA,Cadarache, France, [email protected] Institute for Study of the Earth’s Interior, Okayama University, Misasa, Japan, [email protected] Introduction 3University of Hyogo, Hyogo, Japan, [email protected] 4 The main thrust of this work is to bring some answers to the National Synchrotron Radiation Research Center, SPring-8, following question: what either distinct or combined role do the Hyogo, Japan, [email protected] different physico-chemical and biological (benthic macro- organisms) play on the reactivity, the transfer and the biotic impact Abstract of metallic contaminants in sediments? To achieve this goal, X-ray Raman spectroscopy (XRS) is a rapidly developing experimentations wre carried out in microcosmes with different technique for in situ observation of the near edge structures in the forcing parameters (oxia, anoxia, with and without macro-benthic soft x-ray regime. This region includes the K- and L-edges of most organisms). common silicate melt forming elements including Si, Al, Mg and O. This is the only technique that provides direct in-situ observation of Material and methods the near edge features of these elements at high pressure. This study 15 sediment cores were samples in the Pontabrier lake within uses a panoramic diamond anvil cell and beryllium (Be) gasket in the the village of Compreignac north of Limoges (Haute-Vienne, through gasket geometry to investigate the oxygen (O) K-edge France). These sediments are heavily contaminated in uranium (34 within CaMgSi2O6 glass, an important high pressure phase. 317 Bq/Kg m.s.). Cores were untouched and were used as the Experiments were performed on the Taiwanese inelastic x-ray characterisation cores (cores « C »). 6 other cores were then scattering beamline BL12XU at SPring 8, Japan. depleted in benthic macro-organisms by addition of niyrogen gas for Preliminary results show a prominent edge feature at 533 eV. 24 h. Half of the cores depleted in macro-organisms were populated With increasing pressure the edge first shifts to slightly lower with 1060 Tubifex tubifex by core with a mean density of 60 000 values (~0.1 eV/GPa) until 17.5 GPa whereupon the edge shift individualss /m² close to what observed in some environments becomes positive. At 8 GPa, the O K-edge changes from being a (cores « T »). The three remaining cores were submitted to gamma single asymmetric peak (537 eV) at ambient pressure to a distinct irradiation (delivered dose: 40 Kgy) during 6 days t sterilise them double peak (537 and 541 eV). Above 8 GPa, the main peak retains (cores « S »). At day 0 and after a month, peepers-gels DET probes these features though the resolution becomes degraded. The changes (diffusive equilibrium in thin-films) were inserted for 24 h in all in the O K-edge are related to the changes in Si-O-Si glass network. probes to determine the concentration profiles of the dissolved In comparison to XRS studies on the O K-edge of SiO2[1], and species. its polymorphs, the edge features for CaMgSi2O6 glass are substantially more broad, indicating more complex bonding Results and conclusion interactions of local structures. Additionally, the development of an Results suggested the enhanced release of uranium from the intense peak at 544 eV in SiO2 glass, thought to represent the [6] sediment by bioturbation (figure 1). The present study provides presence of Si found in stishovite, is lacking. Although the further evidence of the enhanced release of uranium from the absense of the 544 eV feature does not preclude the presence of sediment by bioturbation, possibly from the dissolutive reduction of higher coordinated Si species within the glass structure, it does iron oxyhydroxydes coated with uranium. The bioturbation is in fact suggest that a more in-depth understanding of the O K-edge under likely to shift the redox processes with the further addition of pressure is essential to directly observing, interpreting and dissolved oxygen by the Tubifex activity. understanding the structural role of O within silicate melts at high pressure. Figure 1: U pore-water profiles by DET U (μmol/l) 10 [1] Lin, Fukui, Prendergast, Okuchi, Cai, Hiraoka, Yoo, Trave, Eng,

-10 0 5 10 15 20 Hu and Chow (2007) Physical Reviews B 75, 012201:1-4.

-30 -50

-70

-90 depth (mm) core C -110 core T core S -130

-150

Mineralogical Magazine | www.minersoc.org 2139 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Volatile budget of the 2011 Cordon Experimental simulation of brine re- Caulle eruption (Chile) from various injection under subcritical and and integrated approaches. supercritical conditions 1* 2 1 3 1 2 S. MOUNE , S. CARN , N. CLUZEL , F. AGUILERA , A. BRUCE W. MOUNTAIN * AND ROMAIN SONNEY 4 AMIGO 1GNS Science, Wairakei Research Centre, Taupo, New Zealand, 1. Laboratoire Magmas et Volcans, OPGC-UBP-CNRS, Clermont- [email protected] (*presenting author) Ferrand, France, [email protected] 2University of Neuchâtel, Centre for Hydrogeology and 2. Department of Geological and Mining Engineering and Sciences, Geothermics (CHYN), Neuchâtel, Switzerland, MTU, Houghton, USA, [email protected] [email protected] 3. Departamento de Geología, Universidad de Atacama, Copiapó, Chile, [email protected] The re-injection of flashed brine at geothermal power plants is 4. SERNAGEONIM, Santiago, Chile, [email protected] used to avoid adverse impacts of surface disposal. These fluids contain solutes that can precipitate and thus are detrimental to re- Estimates of volatile budgets for volcanic eruptions are often based injection aquifer permeability. The deposition of silica is a on volatile concentrations measured in melt inclusions (MIs) versus particular issue that must be managed through brine aging and/or acid/base dosing. These treatments modify brine properties such that groundmass glass and on measurements made by direct sampling and it is highly out of equilibrium with the aquifer mineralogy. The re- remote sensing techniques. Here, we present new measurements and injection of fluids into deep (>4 km) drillholes, that may encounter estimates of volatile budget of the 2011 Cordon Caulle eruption in supercritical conditions, also poses interesting questions in terms of Chile. The eruption from the Cordón Caulle rift zone, part of the fluid-rock interactions influencing reservoir permeability. Existing thermodynamic data used in modelling programmes are insufficient basaltic-to-rhyolitic Puyehue-Cordón Caulle volcanic complex, to provide adequate information on the effects of fluid-rock began on 4 June 2011. The first phase of the eruption was interactions in these situations. A viable alternative is direct characterized by an explosion from Cordón Caulle that produced a simulation using experimental apparati. 5-km-wide ash-and-gas plume that rose to an altitude of 12.2 km Re-injection scenarios have been simulated using a continuous flow apparatus. The experiments replicate the interaction between a.s.l. We used three different approaches to assess the volatile waste brine with fractured greywacke, a typical re-injection aquifer budget and how the volatile content of the magma controls the lithology at power plants in the Taupo Volcanic Zone. Deoxygenated

explosivity of such an eruption. brine from Kawerau power station (SiO2 950 mg/kg, Na 799 mg/kg, 1- Pumice samples were collected on June 18th, a few hours after K 131 mg/kg, Cl 1027 mg/kg, SO4 423 mg/kg) was reacted with crushed, sieved and cleaned greywacke at T/P conditions of their eruption. Volatile (S, Cl, F) and major element concentrations 157oC/27 bar, 204oC/35 bar and 400oC/279 bar. At the lowest were measured in MIs trapped in plagioclase (An54-56) and temperature both polymerized and depolymerized brine were used to pyroxene (Mg#39-44) phenocrysts and also in groundmass. assess the effect of fluid aging. SEM/EDS examination showed that Homogeneous dacitic to rhyolitic compositions were observed in polymerized brine produced a continuous coating of amorphous silica composed of variable size silica spherules (<500 nm) the MIs with maximum concentrations up to 160ppm S, 2600ppm Cl cemented by dissolved monomeric silica. Using depolymerized and 800ppm F. The difference between the maximum volatile brine, amorphous silica was also produced, the spherule size was o concentrations in the MIs and those measured in the groundmass uniform (80 nm) and the coating was more discontinuous. At 204 C, precipitated minerals include chlorite, potassium feldspar, a clay indicates that ~0.2Mt SO2, 0.5Mt HCl and 0.3Mt HF were released mineral phase and a Ca-Na aluminosilicate, most likely a zeolite, into the atmosphere during the Cordon Caulle eruption. based on its morphology. SiO2 concentration dropped below

2- Satellite remote sensing data from instruments in NASA’s A- amorphous silica saturation but no SiO2 polymorph was identified Train spacecraft constellation, including the Ozone Monitoring indicating that the decrease in SiO2 concentration was the result of precipitation of the minerals listed above. At 400oC, the surfaces of Instrument (OMI) on Aura and the Atmospheric Infrared Sounder the greywacke fragments were covered with continous coating of (AIRS) on Aqua, indicate a total SO2 emission of ~0.2 Mt from the acicular secondary minerals. These include a fibrous Na-Ca-Fe-Mg initial explosive phase of the 2011 Cordon Caulle eruption. The aluminosilicate (pargasite?), a Na-Fe silicate with a distinct Microwave Limb Sounder (MLS) also detected HCl in the volcanic amphibole morpholgy (riebeckite?) and an unidentified Ca- aluminosilicate. Titanite was also present, likely derived from the plume, providing some constraints on the SO /HCl ratio. 2 sample chamber. These experiments show that laboratory 3- These two previous preliminary results will be discussed and simulations can be successfully used to reproduce fluid-mineral compared with ash-leachate analyses. Leachates from pristine ash interactions that correlate with temperature conditions found in re- collected on June 21st will also provide a plume-gas proxy. injection aquifers. They also provide information on changes in surface roughness and permeability of fractures during re-injection of geothermal brines.

Mineralogical Magazine | www.minersoc.org 2140 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Compositional trends in tourmalines An integrated study with from granites and quartz-tourmaline benthocosms on the impact of different functional groups of rocks from the Penamacor-Monsanto macrofauna on benthic N-processes in pluton (Eastern Central Portugal) coastal sediments of the St. Lawrence Estuary 1,2 3 4 1* 2 I. RIBEIRO DA COSTA , I.M. ANTUNES , F. GUIMARÃES , J.M. AURÉLIA MOURET , GWÉNAËLLE CHAILLOU , PHILIPPE 2 5 1,2 2* 3 4 5 F. RAMOS ,C. RECIO , F.J.A.S. BARRIGA , C. MOURÃO ARCHAMBAULT , ROXANE MARANGER , BJORN SUNDBY AND 6 ALFONSO MUCCI

1 1 Departamento de Geologia, Faculdade de Ciências da Universidade Institut des Sciences de la MER-UQAR, Rimouski, Canada, de Lisboa, Portugal, [email protected], [email protected] [email protected] (* presenting author) 2 2 CREMINER/LARSyS (Lab.Assoc.), Portugal, Institut des Sciences de la MER-UQAR, Rimouski, Canada, [email protected], [email protected] (*presenting author) [email protected] 3 3 Escola Superior Agrária, Instituto Politécnico de Castelo Branco, Université du Québec à Rimouski, Rimouski, Canada, Portugal, [email protected] [email protected] 4 4 LNEG: Laboratório Nacional de Energia e Geologia (S. Mamede de Université de Montréal, Montreal, Canada, Infesta), Portugal, [email protected] [email protected] 5 Servicio General de Isótopos Estables, Facultad de Ciéncias de la 6McGill University, Earth and Planetary Sciences, Montreal, Canada, Universidad de Salamanca, Spain, [email protected] [email protected] 6McGill University, Earth and Planetary Sciences, Montreal, Canada, Abstract [email protected] Peraluminous two-mica granites are predominant in the late- Previous studies in the Laurentian Channel revealed that 2/3 of Hercynian Penamacor-Monsanto pluton [1], intrusive into a massive the dissolved oxygen depletion of bottom water is caused by changes schist-greywacke sequence, and most marginal granites contain in ocean circulation patterns in the northwestern Atlantic [1]. tourmaline, hinting at late-magmatic boron-metasomatism. This is Nevertheless, elevated organic matter fluxes to the seafloor, from eutrophication due to enhanced fertilizer use in the watershed, could further supported by occurrences of quartz (r mica) -tourmaline also increase locally the bottom water and sedimentary oxygen rocks along the narrow contact aureole. Tourmaline colour and demand. The aim of this study was to improve the knowledge of the colour zoning patterns are related to Ti abundance and Fe/Mg ratios, N budget in the coastal environments of the St Lawrence Estuary in according to X-ray mapping. Notwithstanding ubiquitous late order to better evaluate system’s capacity to buffer anthropogenic N loading. Some studies showed that macrofauna of these coastal crystallization of euhedral to subhedral tourmaline in the marginal environments have an impact on benthic biogeochemical fluxes. granites, textural and X-ray compositional evidence suggest that Develop the understanding on complex interactions between some tourmaline may nucleate on biotite and eventually replace it. sediment and benthos requires the use of innovative approaches Given their high proportion of X-site vacancies (58 to 78%), because fauna activity and patchy distribution of organic matter introduce another level of complexity and initiate a heterogenic tourmalines from marginal granites are classified as foitites and those pattern of microzones. In this perspective, a closed-circulation, in the quartz-tourmaline rocks as foitites and Mg-foitites. Schorl-type water jacket-insulated laboratory basins, called benthocosms, were substitution predominates over elbaite-type substitution, especially in used to preserve sediment mesocosms of 0.16 m2 surface area, with granite tourmalines, which tend to be richer in Fe2+ and Al (r Mn) controlled conditions of salinity and temperature. 5 different treatments were set up to specify the impact of different functional and poorer in Mg and Na (r Ca, Cr, V, Ti) than tourmalines from groups of macrofauna on nitrification, denitrification, anammox. A quartz-tourmaline rocks. In spite of their chemical differences, both treatment without fauna was compared to a treatement with tourmaline populations seem to bear a close genetic relationship, as biodiffusers (Mya arenaria and Macoma balthica) and to a treatment with biodiffusers + gallery-diffusers (Nereis virens). evidenced in the (Fe+Mn)/(Fe+Mn+Mg) vs. Al/(Al+Mg+Li) linear + + Additional treatments were amended with NH4 to mimic NH4 trend, strongly suggesting that the same late-magmatic, B-enriched excretion by organisms or with allylthiourea to inhibit nitrification - - + aqueous fluid was involved in their genesis. by sediment bacteria. Fluxes of O2, NO3 , NO2 , NH4 have been Analytical and isotopic work currently in progress will soon add determined by incubations. O2 profiles were realised with microelectrodes and the vertical distributions of NO -, NO -, NH + to these preliminary results on the Penamacor-Monsanto tourmalines. 3 2 4 were measured on porewater extracted by centrifugation. Isotope Pairing Technique was used to determine denitrification, anammox We acknowledge financial support of PTDC/CTE-GIX/116204/2009. rates. [1] Gilbert et al. (2005) Limnology and Oceanography 50(50), [1] Neiva, A.M.R & Costa Campos, T.F. (1993) Mem. Not. Publ. 1654-1666. [2] Michaud et al. (2005) Journal of Experimental Mus. Lab. Mineral. Geol. Univ. Coimbra 116,21-47. Marine Biology and Ecology 326, 77-88. [3] Michaud et al. (2009) Journal of Marine Research 67, 43-70.

Mineralogical Magazine | www.minersoc.org 2141 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Mineral reactions at high pH Planetary scale Sr isotopic relevant to radwaste disposal: a 15 heterogeneity 1* 2,3 4 year experimental study FREDERIC MOYNIER , JAMES M.D. DAY , WATARU OKUI , 4 5 1 2 3 TETSUYA YOKOYAMA , AUDREY BOUVIER , RICHARD J. E.B.A. MOYCE *, K. MORRIS , A.E. MILODOWSKI , C. 3 1 3 1 WALKER , FRANK A. PODOSEK ROCHELLE , S. SHAW 1 1 Department of Earth and Planetery Science and McDonnell Center Earth Surface Scienec Institute, University of Leeds, Leeds, UK for Space Sciences, Washington University, St Louis, MO 63130, (*correspondence: [email protected]) USA ([email protected]) (*presenting author) 2Research Centre for Radwaste and Decommissioining, SEAES, The 2Geosciences Research Division, Scripps Institution of University of Manchester, Manchester, UK Oceanography, La Jolla, CA 92093-0244, USA 3 3British Geological Survey, Keyworth, UK Department of Geology, University of Maryland, College Park, MD 20742, USA 4Department of Earth and Planetary Sciences, Tokyo Institute of The use of cement within waste forms, engineering and Technology, Tokyo 152–8551, Japan 5 potentially as backfill in the geological disposal of radioactive waste Department of Earth Sciences, University of Minnesota, Minneapolis, MN 55455-0231 USA will produce a high pH (~pH 13-10) leachate plume as the geological disposal facility (GDF) evolves over hundreds to millions of years. Isotopic anomalies in planetary materials may reflect both early solar nebular heterogeneity inherited from presolar stellar sources This plume will create a chemically disturbed zone (CDZ) within the [1], and processes that generated non-mass dependent isotopic host rock causing alteration, dissolution and secondary precipitation fractionations [2,3]. The characterization of isotopic variations in heavy elements among early Solar System materials brings of minerals. This has clear potential to change the rock’s physical important insight into the stellar environment and formation of the and chemical properties and affect radionuclide transport in the solar system, and may also provide critical information about initial isotopic ratios relevant to long-term chronological applications [4]. geosphere through alteration of flow paths or change in the host rock One such heavy element, strontium, is a central element in the sorption capacity for radionuclides. geosciences due to the widespread application of the long-lived 87Rb-87Sr radioactive system (O=1.393x10-11y-1 [5]) as a Here we describe analysis of a unique series of batch chronological tool. experiments which contain Borrowdale Volcanic Group (BVG) rock Through high-precision Sr isotopic measurements we show that the stable isotopes of Sr were heterogeneously distributed at both (quartz, orthoclase and dolomite with clay coatings) reacted in CDZ the mineral- and the planetary-scale in the early Solar System, and leachates at 70 ºC for 15 years. Two leachates were used: young also that the Sr isotopic heterogeneities correlate with mass cement leachate (pH 13.00, KOH and NaOH dominated); and independent oxygen isotope variations. This correlation implies that most Solar System material was formed by mixing of at least two evolved leachate equilibrated with a model deep groundwater (pH isotopically distinct components: a refractory inclusion-like 84 88 16 [1] component (rich in p-process Sr or s-process Sr, and O), and 12.2, Ca(OH)2 and NaCl dominated) . Experiments were an H-chondrite-like component (poor in 84Sr or 88Sr, and 16O). characterised at 15 months and in this most recent work, at 15 years. The heterogeneous distribution of Sr isotopes, most notably 84 87 86 At 15 months mineral dissolution and formation of Ca-bearing with respect to Sr, may indicate that variations in initial Sr/ Sr of early Solar System materials reflect isotopic heterogeneity silicate phases, e.g. apophyllite and Ca-K-Al silicate clays, was instead of having a chronological significance, as interpreted observed. However, recent work shows that by 15 years, extensive previously. For example, the corrected age difference between the formation of refractory inclusions and eucrites, as determined from de-dolomitisation had occurred; here the dissolution of CaMg(CO3)2 Sr isotopic differences, is much shorter than previously suggested, 2+ resulted in extensive CaCO3 re-precipitation and release of Mg . By placing the Sr chronology in agreement with other long and short- lived systems, such as U-Pb and Mn-Cr [6]. 15 years, it is apparent that this Mg2+ had reacted with silica in

solution and clay particles on the primary mineral surfaces to produce Mg(K)(Al)-silicates of varying composition, structure and [1] Birck, J. L.. Rev Mineral Geochem 55, 26-63 (2004). [2] Fujii, morphology as the major alteration products. The Ca-bearing T., Moynier, F. & Albarède, F. Earth Planet. Sci. Lett. 247, 1-9 silicates observed after 15 months of reaction were not present at 15 (2006).[3] Thiemens, M. H.. Science 283, 341-345 (1999). [4] Brennecka, G. A. et al. Science 327, 449-451, (2010). [5] Nebel, O., years. At all points, the alteration level was greatest in the young Scherer, E. E. & Mezger, K. Earth Planet. Sci. Lett. 301, 1-8, leachate, but the processes described occurred in both fluids. (2011). [6] Lugmair, G. W. & Shukolyukov, A. Geochim. Overall, these results demonstrate that the stability of secondary Cosmochim. Acta 62, 2863-2886 (1998). phases formed within the CDZ may change significantly over time and may affect both flow and radionuclide speciation. Clearly, this has implications for GDF safety case development.

[1] Rochelle et al. (1997) BGS technical report WE/97/16

Mineralogical Magazine | www.minersoc.org 2142 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Exploring the relative influence of Binding environment of As(V) during fluid and particle residence times on microbial reduction of As-bearing biogenic Fe(III) minerals chemical weathering using a coupled 1 1 2 1 E. M. MUEHE *, L. SCHEER , G.MORIN , A. KAPPLER geomorphic and geochemical model

1* 2 3 SIMON M. MUDD , KYUNGSOO YOO , KATE MAHER 1 Geomicrobiology, University of Tuebingen, Germany 1School of GeoSciences, University of Edinburgh, Edinburgh, UK, [email protected] (* presenting author) [email protected] (* presenting author) 2 Environmental Mineralogy, IMPMC, CNRS-UPMC, France 2Department of Soil, Water and Climate, University of Minnesota, [email protected] St. Paul, MN, USA, [email protected] 3 School of Earth Sciences, Stanford University, Stanford, CA, USA, [email protected] Aqueous As in As-contaminated groundwater and soil enters the

human food chain (in)directly via drinking water, plants and animals, Minerals enter the weathering zone as landscapes erode and potentially having a devastating impact on the health of people. weathering fronts propagate downward through the near surface. In Correspondingly, research has put its focus on (bio)geochemical many, if not most landscapes, this process involves minerals first processes leading to the mobilization (release) and immobilization being chemically weathered and subsequently being subject to both (removal) of As from aquifers and soil. Previous studies by chemical weathering and mechanical disturbance. The timescale of Hohmann et al. [1] revealed that Fe(II)-oxidizing bacteria efficiently mineral transformation is on the order of thousands to millions of immobilize the two most common inorganic As species, As(V) and years [1]; this timescale is similar to the residence time of minerals As(III), in aqueous systems by the formation of biogenic Fe(III) within the physically disturbed, mobile regolith of eroding oxyhydroxides (ferrihydrite and goethite). Detailed analyses of landscapes [2]. The chemistry of mobile weathered material on these biogenic precipitates formed in the presence of dissolved As eroding hillslopes will reflect the integrated effects of different indicated As is efficiently removed from the aqueous phase via weathering environments along the hillslope profile. Thus it is sorption to the mineral surfaces [2]. crucial to account for sediment transport if one is to use the solid Environments that contain Fe(III) minerals and organic matter are state chemistry of hillslope materials to infer weathering rates over usually also inhabited by Fe(III)-reducing microorganisms, long (103-106 yr) timescales [3, 4]. It has been postulated that the suggesting that potentially microbial reduction of the biogenic rate that minerals weather is partly a function of the time they spend Fe(III) (oxyhydr)oxides occurs. The microbially-mediated in the weathering zone [5] and this time is closely related to the dissolution of these biogenic Fe(III) minerals could cause a release erosion rate. It has also been suggested that fluid, rather than mineral of the bound As or result in further immobilization of As due to the residence time plays a dominant role in determining the rate of formation of secondary Fe(II/III) mineral phases. Additionally, the chemical weathering in near-surface materials [6]. To examine the redox state of As might change during microbial Fe cycling and thus relative importance of mineral vs. fluid residence time or to affect the mobility of As, since As(III) is generally more mobile examine if these two factors co-evolve we have developed a than As(V). numerical model that traces minerals through the weathering zone, In the study presented here, we followed the reduction of biogenic including their transit through a mobile, mixed regolith. The model As-bearing Fe(III) minerals by the Fe(III)-reducer Shewanella is designed to assimilate field data so that hypotheses concerning oneidensis MR-1. Arsenic concentration and oxidation state were the controls of chemical weathering rates can be tested with solid monitored in the liquid and solid phases. Mineralogy of the state chemistry and mineralogy from soil pits or cores. Chemical incubated solid phases was determined by X-ray diffraction and weathering in the model can be simulated using either the time the electron microscopy, whereas the As redox species and bonding mineral has spent in the weathering zone or using a geochemical environment in the mineral precipitates were analyzed by X-ray model that accounts for fluid flow and chemistry. Here we use the adsorption spectroscopy. We found that As(V) is immobilized model to examine the sensitivity of weathering zone evolution to during microbial reduction of biogenic As-bearing Fe(III) erosion rate. We also compare model predictions to geochemical (oxyhydr)oxides while As(III) is mobilized to a significant extent. data from a transect in Tennessee Valley, California in order to The immobilized As(V) is bound either to the remaining goethite or explore if variations in either fluid or mineral residence times can to the newly formed Fe(II) minerals and no mobilization occurred explain the observed geochemical patterns. even though As(V) was transformed to As(III).

[1] Lasaga et al. (1994) Geochima et Cosmochimica Acta 58, 2361- 2386. [1] Hohmann et al. (2010) ES&T 44, 94-101. [2] Hohmann et al. [2] Mudd and Yoo (2010) Journal of Geophysical Research-Earth (2011) GCA 75, 4699-4712. Surface 115, doi:10.1029/2009JF001591. [3] Mudd and Furbish (2006) Journal of Geophysical Research- Earth Surface 111, doi:10.1029/2005JF000343. [4] Yoo et al. (2007) Journal of Geophysical Research-Earth Surface, 112, doi:10.1029/2005JF000402. [5] White and Brantley (2003) Chemical Geology 202, 479-506. [6] Maher (2010) Earth and Planetary Sci. Letters 294, 101-110.

Mineralogical Magazine | www.minersoc.org 2143 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Early planetary differentiation and Sr-Nd-Hf-Pb isotopic constraints on volatile accretion recorded in deep the origin of alkalic basalts in the mantle Xenon isotopes northern Cascade Arc 1* 1 1 SUJOY MUKHOPADHYAY , MARIA PETO , RITA PARAI , AND E. K. MULLEN*, M. CARPENTIER AND D. WEIS 1 JONATHAN TUCKER PCIGR, University of British Columbia, Vancouver, BC Canada 1Harvard University, Cambridge, MA, USA, [email protected] V6T 1Z4, [email protected] (*presenting author)

129Xe, produced from the radioactive decay of extinct 129I, and Calc-alkaline basalts are the predominant primitive magmas in 136Xe, produced from extinct 244Pu and extant 238U, have provided the Cascade Arc. However, the northernmost segment of the arc, the important constraints on early mantle outgassing and volatile loss Garibaldi Volcanic Belt (GVB), shows a progressive northerly shift from Earth1,2. The low ratios of radiogenic to non-radiogenic xenon from calc-alkaline to alkalic basalts. At the northern end of the arc, (129Xe/130Xe) in ocean island basalts (OIBs) compared to mid-ocean hawaiite and basanite occur at Salal Glacier, Bridge River, and Mt. ridge basalts (MORBs) have been used as evidence for the existence Meager volcanic complexes. The gradient in alkalinity is of a relatively undegassed primitive deep mantle reservoir1. accompanied by a northerly reduction in the “arc signature” and However, the low 129Xe/130Xe ratios in OIBs have also been increases in P and T of basalt generation. These trends may be related attributed to mixing between subducted atmospheric Xe with MORB to the age of the subducting plate, which decreases by ~4 Myr, Xe, obviating the need for a less degassed mantle reservoir3,4. potentially leading to reduced slab inputs and consequently smaller We present new noble gas data from OIBs and MORBs that melt fractions formed at greater depths [1]. We have obtained new demonstrate for the first time that the lower 129Xe/130Xe ratios in high-precision whole-rock Sr-Nd-Pb-Hf isotope and trace element OIBs are derived from a lower I/Xe ratio in the OIB mantle source data on GVB basalts to geochemically characterize the mantle and cannot be explained solely through mixing between atmospheric beneath each volcanic center and determine whether the geochemical Xe and MORB-type Xe. As 129I became extinct prior to 100 Myrs gradients displayed by the basalts can be explained solely by changes after the start of the Solar System, OIB and MORB mantle sources in slab input or require multiple mantle components. must have differentiated by 4.45 Ga and subsequent mixing must Relative to other primitive Cascade arc basalts, GVB basalts have been limited. Thus, if the Moon-forming giant impact led to have lower 208Pb/204Pb at a given 206Pb/204Pb (18.67-18.92) and 87 86 large scale planetary equilibration, it must have happened within 100 higher İNd (3.8-8.5) at a given Sr/ Sr (0.70310-0.70396). The Myrs of the start of the Solar System. alkalic GVB basalts have the most depleted Pb isotopic ratios yet The new precise xenon measurements also allow us to compute identified in the Cascade Arc. In Pb isotopic space, the GVB defines the proportion of Pu to U-derived fission Xe. Our measurements a linear array extending from Juan de Fuca MORB to subducting indicate that the plume source has a higher proportion of Pu- to U- sediment in the northern Cascadia basin, which we interpret as a derived fission Xe, requiring the plume source to be less degassed mixing line indicating variable sediment input to the mantle. A than the MORB source and supporting the long-term separation of northerly La/Nb decrease from ~4.25 at Glacier Peak to ~0.78 at MORB and OIB mantle sources. These conclusion are independent Bridge River confirms the reduction in arc signature, but an inverse of noble gas concentrations and the partitioning behavior of the correlation between İNd and İHf (8.7-13.3) indicates arc-parallel noble gases with respect to their radiogenic parents. mixing between two isotopically distinct mantle sources, one Calculated I/Pu ratios for the plume source is lower than the dominating in the south and the other in the north. MORB source. This suggests that early accretion was volatile-poor Trace element modeling, phase equilibria and thermobarometry compared to later accreting material, supporting the hypothesis of indicate that the alkalic GVB basalts segregated from the mantle at heterogeneous accretion5. Overall, the noble gases suggest at least high pressures and MORB-like temperatures (up to ~2.7 GPa, two separate sources of volatiles for Earth and require that 4.45 1475°C) and have garnet lherzolite residues. The mantle source is not Gyrs of mantle convection have not erased the signature of Earth’s modified by a subduction component and is isotopically depleted, yet early differentiation. Finally, if noble gases in OIBs are derived from it is enriched in incompatible elements. These correlations indicate the Large Low Shear Wave Velocity Provinces (LLSVPs), then our either long-term mantle source depletion coupled with a recent study requires LLSVPs to be stable features that have existed since metasomatic enrichment event, or extremely low melt fractions. In the formation of the Earth and are not exclusively composed of contrast, calc-alkaline basalts of the southern GVB (Mt. Baker, subducted slabs. Glacier Peak) were generated near the base of the crust from depleted lherzolite or harzburgite metasomatized by sediment melt or fluid. [1] Allegre, et al. (1987) EPSL 81, 127-150. [2] Marty (1987) EPSL Because the alkalic basalts lack an arc signature, have a hot, 94, 45-56. [3] Holland & Ballentine (2006) Nature 441, 186-191. recently-enriched mantle source, and are located at the termination of [4] Trieloff & Kunz (2005) PEPI 148, 13-38. [5] Schonbachler et al the currently subducting slab, we propose that they are generated by (2010) Science 328, 884-887. a “slab edge effect”. Decompression melting is triggered by upwelling of asthenospheric mantle through a window between the active Juan de Fuca plate and near-stagnant Explorer plate [2,3].

[1] Green (2006) Lithos 87, 23-49. [2] Audet et al. (2008) Geology 36, 895-898. [3] Riddihough (1984) J. Geoph. Res. 89, 6980-6994.

Mineralogical Magazine | www.minersoc.org 2144 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Accuracy of in-situ Sr isotope analysis Evaluation of contaminated sediment of biogenic phosphates by LA-MC- remediation techniques 1* ICPMS – a problem reassessed CATHERINE N. MULLIGAN

1, *) 2 WOLFGANG MÜLLER , ROBERT ANCZKIEWICZ 1*Concordia University, Montreal, Canada, [email protected] 1Dept. of Earth Sciences, Royal Holloway University of London,

Egham, UK, [email protected] Introduction 2Inst. of Geological Sciences, Polish Academy of Sciences, Krakow, An evaluation of the management options must be made for Poland, [email protected] contaminated sites. In particular, the various techniques must be considered for the remediation of sediments when the sediment In-situ Sr isotope analysis by LA-MC-ICPMS has been available leads to the accumulation of contaminants in aquatic life or when the for more than fifteen years [1]. While precise and accurate data can release of hazardous materials from sediments becomes a serious be obtained in this way for (high-Sr) carbonates and other materials, problem. The options can include capping, dredging, or physical, for phosphates accuracy (and precision) of in-situ analyzed Sr biological, and/or chemical treatments. Sustainable management isotope data have proven difficult to obtain [2, 3]. Specific to Ca- options for contaminated sediments are required and will be evaluated. In situ remediation could be beneficial over dredging due phosphates, CaPO, a molecular interference on mass 87 to a reduction in costs and lack of solid disposal requirements. (40Ca31P16O), as well as doubly-charged Yb & Er in case of REE-

rich inorganic apatite have been invoked as analytical obstacles, 84,86 87 Approach besides Kr, Rb, Ca-Argides. Moreover, all is exacerbated by Selection of the most appropriate remediation technology the relatively low Sr concentrations of biogenic phosphates (<100 must coincide with the environmental characteristics of the site and to few 100 ppm Sr). the ongoing sediment fate and transport processes. To be In view of the importance of Sr-isotopes in biogenic phosphate sustainable, the risk at the site must be reduced, and the risk should as mobility proxy in vertebrates - in teeth potentially providing sub- not be transferred to another site. The treatment must reduce the risk to human health and the environment. Cost-effectiveness and seasonal resolution when analyzed in-situ by LA-MC-ICPMS - we permanent solutions are significant factors in determining the have evaluated in-situ Sr-isotope analysis for a range of biogenic treatment. Sites vary substantially, and there can be substantial phosphates. Using a RESOlution M-50 193 nm excimer laser- uncertainty involved in the evaluation process. However, decisions ablation system, featuring a Laurin two-volume cell, coupled to a must be made based on the information available. Neptune MC-ICPMS, we evaluate spectral interferences on 87Sr by Both in situ and ex situ treatment approaches are examined. focussing on: 1) Routine ‘robust’ plasma conditions (ThO+/Th+ < 0.1 For example, environmental dredging requires evaluation of the risk %), which because of the highest oxide bond strength for ThO [4] of dredging, determination of disposal methods and/or potential beneficial use. Innovative integrated decontamination technologies imply that all other oxides will be present in lower abundances. 2) must be utilized. Accurate naturally invariant 84Sr/86Sr ratio (0.0565 after mass bias

correction) as monitor of appropriate interference corrections (Kr, 2+ Results and Conclusions CaAr, REE ). 3) Careful mass scans at medium mass resolution To work towards sustainability, indicators must be identified 87 (M/ΔM = 4000) because CaPO and Sr are resolvable above M/ΔM and quantified, including waste must be minimized, natural resources = 3900. 4) Focus on the accuracy of the 87Rb-correction on mass 87 must be conserved, landfill deposition should be minimized and since mammalian bioapatite can have relatively high 85Rb/86Sr of up benthic habitats and wetlands must not be lost and must be protected. to ~0.01 and sometimes even higher. Innovative integrated decontamination technologies must be utilized. For the analytical (plasma) conditions utilized, we find no The fate and transport of contaminants must be understood more thoroughly to develop appropriate strategies. A long term vision is evidence for any molecular interference (CaPO) at mass 87 using needed. Otherwise, natural resources will continue to be depleted, medium resolution mass scans. Furthermore we obtain accurate landfills will continue to be filled with contaminated sediments, and 84 86 Sr/ Sr ratios (0.0565) for both shark teeth (high-Sr) as well as biodiversity in the aquatic geoenvironment will be diminished. mammalian enamel (few 100 ppm Sr maximum). 87Sr/86Sr ratios for Integrated innovative management practices need to be developed modern shark teeth of 0.70917 ± 3 (2 SD) are indistinguishable and applied such as in situ techniques that reduce waste management from modern seawater (0.70917). Comparing TIMS and LA-MC- requirements. ICPMS Sr isotope data of the same tooth enamel characterized by variable Sr-isotope ratios inevitably highlights the problem of scale because mg-sized fragments are utilized for TIMS vs. ~100 μm spot sizes for LA-ICPMS. Nevertheless we find very good agreement in 87Sr/86Sr for corresponding enamel sections using both methodologies, but the ultimate accuracy depends on the magnitude of the necessary 87Rb correction; corresponding results will be presented. [1] Christensen et al (1995) Earth Planet. Sci. Lett. 136, 79-85. [2] Simonetti et al (2008) Archaeometry 50, 371-385. [3] Horstwood et al (2008) Geochim. Cosmochim. Acta 72, 5659-5674. [4] Kent & Ungerer (2005) J. Anal. Atom. Spectrom. 20, 1256-1262.

Mineralogical Magazine | www.minersoc.org 2145 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Arsenic Mobility is Mediated by Combining macroscopic invasion Bacterial Reduction in New Jersey percolation with mass transfer to Shallow Groundwater model bubble-facilitated transport of 1* 2 2 A. C. MUMFORD , J. L. BARRINGER , P. A. REILLY AND L. VOCs in groundwater 1 Y. YOUNG 1* 1 KEVIN G. MUMFORD , PAUL R. HEGELE , MAGDALENA M. 1 2,3 3 Rutgers University, New Brunswick, NJ, USA KROL AND BRENT E. SLEEP [email protected], (*presenting author) 1 [email protected] Queen’s University, Dept. of Civil Engineering, Kingston, Ontario, 2US Geological Survey, NJ Water Science Center , West Trenton, Canada, [email protected] (*presenting author) NJ, USA. [email protected], [email protected] 2Western University, Dept. of Civil and Environmental Engineering, London, Ontario, Canada, [email protected] Introduction 3University of Toronto, Dept. of Civil Engineering, Toronto, The mobilization of arsenic bound to aquifer sediments is Ontario, Canada, [email protected] a source of contamination in groundwater in New Jersey. Deep Coastal Plain sediments have average As concentrations of 15-23 Gas bubbles present in otherwise water-saturated porous media mg/kg [1,2], and As concentrations of 26 mg/kg have been recorded in shallow glauconitic sediments[3]. In a prior study [3] we can affect the transport of volatile organic compounds (VOCs) in demonstrated that As reducing bacteria promote As release and groundwater. The partitioning of VOCs to gas bubbles, with the mobility in groundwater at a New Jersey Coastal Plain site. We have bubbles acting as a variable-volume sink, can retard VOC transport, expanded this study to investigate the potential for microbial As and can also affect the transport of other volatile species (e.g., mobilization beneath the streambeds at two other sites, Six Mile Run dissolved atmospheric or biogenic gases). If sufficient gas volumes and Pike Run, in the New Jersey Piedmont. Groundwater at the Six exist for bubbles to be vertically mobilized, the transport is also Mile Run site has an As concentration of 27 μg/L, which is in excess of the 5μg/L limit set by the NJDEP, while the As concentration at affected by the creation of an additional mass transport pathway – the Pike Run site is 2.1 ug/L. the buoyant advection of the bubbles – which can carry mass away Methods: from regions with higher aqueous concentration to those with lower Groundwater was sampled on gaining reaches of Pike Run aqueous concentration, resulting in mass partitioning from the and Six Mile Run in the New Jersey Piedmont Physiographic bubble back to the aqueous phase. This type of transport has been Province, and inoculated into anaerobic microcosms with acetate as observed in a variety of systems, including: the natural attenuation of a carbon source and As(V) as an electron acceptor. Arsenic hydrocarbon plumes, the expansion of trapped gases above non- reduction was monitored by HPLC. Groundwater was filtered on aqueous phase liquid (NAPL) sources, and remediation by in situ site, and DNA was extracted from the filters for amplification and cloning of the16S rRNA gene and the arsenate respiratory reductase thermal treatment. gene, arrA, a biomarker for As(V) respiration [4]. 16S rRNA gene In these types of systems, where the expansion and mobilization sequence data was analyzed using ARB [5] and the SILVA 108 NR of the gas bubbles is controlled by the mass transfer between the 16S rRNA gene database [6]. arrA gene sequence analysis was aqueous phase and the trapped gas phase, it is important to model performed using ARB [6]. Operational Taxonomic Unit (OTU) both the partitioning of multipe volatile species and the subsequent analysis was performed with mothur [7]. discontinuous bubble flow as mass transfer and immicible Results and Conclusions displacement occur over similar time scales. One promising Microcosms developed from Six Mile Run groundwater approach is the use of macroscopic invasion percolation (MIP) to reduced 1 mM of As(V) to As(III) in 30 days, while microcosms from Pike Run did not reduce As. Based on a 97% similarity cutoff, model gas movement, combined with continuum-scale simulation of 10 OTUs unique to Six Mile Run were identified, and 11 OTUs aqueous-phase transport and mass transfer between phases. The MIP unique to Pike Run were identified. The sites shared 4 OTUS out of routine can be modified to include gravity for biased vertical growth, the 25 sequenced, suggesting that distinct bacterial communities as well as fragmentation and mobilization to reproduce bubble were present at each site. Based on the arrA gene, distinct arsenic behaviour, provided that gridblock sizes are less than a critical length respiring communities were identified at each site, with 8 unique scale required for mobilization. Here, simulations of VOC transport OTUs found at Six Mile Run, and 11 unique OTUs shared at Pike Run. Globally, the arrA sequences recovered from both Pike Run in the presence of mobilized gas bubbles were compared to an and Six Mile Run are most similar to those recovered from the intermediate-scale laboratory flow cell experiment, where non- Meuse River in France, and distinct from those recovered from monotonic changes in concentrations were observed at higher-than- marine environments. Our findings demonstrate that while the arrA expected elevations above a dense non-aqueous phase liquid gene may indicate the presence of As reducing organisms, (DNAPL) pool. Additional simulations that investigated the microcosm studies are necessary to predict microbial As reduction potential role of bubbles during in situ thermal remediation showed and mobilization from sediments. greater mass removal from a targetted heating area due to bubble

[1] Dooley (1998) The New Jersey Geological Survey Technical formation and mobilization. Finally, a third set of simulations Memorandum 98-1. [2] Dooley (2001) N. J. Geological Survey investigated bubble-facilitated transport of VOCs in heated and Investigation Report [3] Mumford et al. (2012) Water Res. In unheated, heterogeneous systems. Review [4] Malasarn et al. (2004) Science 306, 455. [5] Ludwig et al. (2004) Nucleic Acids Res 32, 1363-1371, [6] Pruesse et al. (2007) Nucleic Acids Res 35, 7188-7196 [7] Schloss et al. (2009) Appl Env Microb 75, 7537-7541

Mineralogical Magazine | www.minersoc.org 2146 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Blatchford Lake intrusive suite, new PGE systematics of refractory geochronology and barometric mantle: role of Pt alloy 1* 2 2 estimates: implications for JAMES E MUNGALL FRANCES JENNER , RICHARD ARCULUS , 2 mineralization JOHN MAVROGENES 1 2 1* 1 University of Toronto, Canada Australian National University, THOMAS MUMFORD , BRIAN COUSENS Canberra, Australia * [email protected] 1Carleton University, Ottawa, Canada, [email protected] (* presenting author) Pt/Pd variability in the mantle and picrites 2Carleton University, Ottawa, Canada, The primitive mantle has slightly sub-chondritic Pt/Pd values [email protected] close to 1.1 [1]. Extreme degrees of melt depletion, as recorded by

decreases in CaO, Al2O3, and increases in Mg/(Mg + Fe) in whole Introduction rock or olivine, confer a distinctively high Pt/Pd ratio to the mantle The Paleoproterozoic Blatchford Lake intrusive suite, can be restite, ranging from 5 to 10 in some massif peridotites to as high as subdivided into two cogenetic separate lobes: a metaluminous > 100 in ultradepleted mantle xenoliths from the Kaapvaal craton western lobe and a peralkaline eastern lobe which is host to the [2,3]. A complementary reduction in Pt/Pd to values similar to unity world class Nechalacho rare metal deposit. The western lobe is observed in a global compilation of data for picrites, which evolve consists of a multi-phase layered gabbroic sequence, cross-cut by a to still lower Pt/Pd approaching 0.1 by fractional crystallization in series of sills varying from syenite to granite. The eastern lobe the absence of sulfides [4]. We present data for primitive boninites comprises a large sub-circular granite that grades to a syenite core. from Chichi Jima and the northern Tonga arc, which equilibrated

Underlying the syenite core is a layered suite of silica- with Fo>90 olivine and show extremely low Pt/Pd with values ranging undersaturated rocks collectively known as the Nechalacho layered from 0.1 to 0.5, while also showing strong depletions in Ir and Ru syenite series (NLSS). Rare metal mineralization occurs in the compared to Rh that we have previously attributed to the existence upper units of the NLSS, which have been overprinted by intense of Ir-Ru alloy or laurite in the restite [5]. hydrothermal alteration. Approximately two kilometers east of the Partition coefficients and models

Nechalacho mineralized zone, two small plutonic stocks, believed to Bulk partition coefficients D*Pt and D*Pd estimated from studies be related to the regional Compton Intrusive suite [2], cross-cut the of fractionated lava lakes are approximately 0.2 - 0.6 and 0.1 - 0.2

peralkaline granite. [6]. Experimental determinations of DPt and DPd for olivine are < In situ U-Pb zircon laser ablation ion-coupled plasma mass 0.01 and 0.006 at the FMQ oxygen buffer [7]; values for pyroxenes spectrometry (LA-ICP-MS) was used to date the Compton Intrusives are similar and, even in chromite they are <0.03 [8]. stocks (1895r5 Ma) and to provide the first reliable age estimate The existence of Pt/Pd fractionations spanning two to three orders for the NLSS (2187r8 Ma). These new dates help define of magnitude between parental picritic magmas and their mantle relationships between phases in the eastern lobe, and resolve residues positively requires the existence of a restite phase with

discrepencies in the chronology of the Blatchford Lake intrusive dramatically higher DPt than DPd. Alloys of Os-Ru-Pt have been suite. observed in mantle peridotite [9,10], and consideration of Os Using the Al-in-hornblende barometer [1], pressure estimates solubility in sulfide liquid and bulk Os concentration in the mantle were made on hornblende and edenite crystals from granitic and requires the existence of Os alloy even in the presence of sulfide syenitic phases of the western lobe. These result indicate a mid- melt in the mantle [11]. Our models show that the range of Pt/Pd crustal emplacement (~3.5 kbar) for the late cross-cutting granite observed in peridotite massifs, mantle xenoliths, boninites, and and syenite sills. Given that the ages between the eastern and western tholeiitic picrites is consistent with the ubiquitous occurrence of lobes are within analytical error, these pressure estimates can be alloy-hosted Pt in amounts ranging from 2 to 7 ppb, whereas Pd used to infer the pressure conditions during crystallization of phases appears to be hosted only by sulfide phases, becoming extremely within the eastern lobe. incompatible once sulfide has been consumed during partial melting. This new geohronological and barometric information helps to The Bushveld complex of SA, with Pt/Pd between 1.5 and 5, is a constrain the overall evolution of the Blatchford Lake intrusive unique exception [12]. An unusual process may have destabilized Pt suite, and therby aids in developing models to explain the alloy in the highly refractory SCLM of the Kaapvaal craton during exceptional enrichment in rare-metals in select phases. emplacement of the Bushveld. References [1] Becker (2006) Geochim Cosmochim Acta 70, 4528-4550. [2] Lorand et al. (1999) J Petrol 40, 957-981. [3] Pearson et al. (2004) Chem Geol 208, 29-59. [4] references available from corresponding author. [5] Mungall et al. (2011) AGU Fall meeting.

[6] Puchtel et al. (2004) Geochim Cosmochim Acta 68, 1361-1383. [7] Brenan et al. (2003) Earth Planet Sci Lett 212, 135-150. [8] [1] Schmidt (1992) Contributions to Mineralogy and Petrology Brenan et al. (2011) Chem Geol in press. [9] Luguet et al (2003) 110, 304-310. [2] Davidson (1978) GSC current research 71-8A, Geochim Cosmochim Acta 67, 1553-1570. [10] Kogiso et al 119-127. (2008) Geochem Geophys Geosys doi:10.1029/2007GC001888. [11] Brenan (2002) Earth Planet Sci Lett 199, 257-268. [12] Barnes et al. (2010) Econ Geol 105, 1491-1511.

Mineralogical Magazine | www.minersoc.org 2147 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts Is the bulk Earth Nb/Ta chondritic? Microchemistry of amphiboles near 1* 2 3 CARSTEN MÜNKER , ANDREAS STRACKE , VERENA BENDEL , the roof of a mafic magma chamber 4 3 1* 1 HERBERT PALME , ANDREAS PACK J. BRENDAN MURPHY , STEPHANIE BLAIS , MICHAEL TUBRETT2, DANIEL MCNEIL1 AND MATTHEW 1 Institut für Geologie und Mineralogie, Universität zu Köln, MIDDLETON1 Germany, [email protected] (* presenting author) 1 St. Francis Xavier University, Earth Sciences, [email protected] 2Institut für Mineralogie, Universität Münster, Germany, 2 Memorial University of Newfoundland, MicroAnalysis Facility - 3GZG, Universität Göttingen, Germany Inco Innovation Centre (MAF-IIC), 4Forschungsinstitut Senckenberg, Frankfurt, Germany The Late Neoproterozoic Greendale Complex is a suite of arc- The accessible silicate Earth is characterized by a Nb deficit of related appinitic rocks ranging from ultramafic to felsic in ca. 30% relative to most groups of chondrites [1]. This Nb deficit composition that crystallized at shallow crustal levels under conditions of high pH2O. Amphibole is the dominant mafic has been attributed to a slightly siderophile affinity of Nb during mineral in ultramafic to mafic rocks and displays the extraordinary high-pressure formation of the Earth’s core [1,2]. The finding of low variability in texture and modal abundance that is characteristic of Nb/Ta ratios in CV chondrites (ca. 17 [1]), however has challenged appinite suites. These features allow sensitivity of amphibole this model, as CV chondrites closely resemble the Earth’s composition (major, trace and REE) to the evolution of water-rich composition in their relative abundances of volatile and refractory magma to be investigated. All amphiboles in mafic and ultramafic rocks are calcic, elements. If the bulk Earth indeed had a CV-chondritic or even lower IV with (Ca+Na)B ≥ 1.34 and NaB < 0.67 apfu, with Si between 6.1 Nb/Ta ratio, the Nb deficit in the silicate Earth would be much less and 7.3. They predominantly range in composition from pronounced, and models using Nb/Ta ratios to assess conditions tschermakite, to tschermakitic hornblende, to magnesio-hornblende IV IV during core formation [e.g., 3,4] would neeed some revision. and display a dominance of edenite (Na,KA + Al = Si ) In order to investigate the cause for the low Nb/Ta in CV substitution. Although each sample exhibits remarkably uniform Mg/(Mg+Fe2+) over a wide range in Si of up to one formula unit, chondrites, we analyzed small ca. 0.6 g slices taken from a single the mafic rock amphiboles are characterized by lower (0.5 to 0.7) piece of Allende [5], together with an aliquot of the Smithsonian Mg/(Mg+Fe2+), compared to the ultramafic rocks (0.7 and 0.9). powder that is representative for bulk Allende. Ratios of HFSE were REE and trace element profiles of amphiboles from mafic rocks determined at high precision using isotope dilution and the Neptune are remarkably consistent. REE profiles are bow-shaped, and are MC-ICPMS at Cologne-Bonn [6] and are compared to high precision characterized by depletion in LREE (La/Sm ≈ 0.61), a slight depletion in HREE (Gd/Yb ≈ 1.55) as well as a negative Eu data for REE previously determined at ETH Zürich and RSES anomaly, which is attributed to co-precipitation of plagioclase. Canberra [5, unpulished]. The Smithsonian Allende powder yielded a REE and trace element profiles of ultramafic amphiboles are Nb/Ta of 19.1±0.8 (2V), within error of values for other chondrite divided into two groups that correspond to different textural groups (19.9±0.6, [1]). Conversely, the Nb/Ta measured for the settings: Group A amphiboles occur in all specimens analyzed and small Allende slices span a wide range from 14.2 to 22.0. Ratios of are very similar to the profiles of the mafic rocks. In contrast, Group B amphiboles display relative enrichment in light REEs Zr/Nb are correlated with Nb contents and range towards values as (La/Sm ≈ 2.05), have lower ΣREE, and lack a negative Eu low as 10, much lower than the chondritic value (13.5, [3]). anomaly relative to Sm and Gd. Group B amphiboles are more The Nb/Ta systematics found for Allende indicate that in enriched in Th and U and show a more pronounced depletion in contrast to Zr-Hf, Nb and Ta are not distributed homogenously in CV Ta, Nb, Ti and Y. Group B amphiboles grew in a reaction chondrites. However, the data for the large Smithsonian powder relationship with olivine and pyroxene. Groups A and B are virtually indistinguishable with respect to the major elements used aliquot suggest that the bulk Allende parent body had a Nb/Ta for amphibole classification, suggesting that REE and selected indistinguishable from other types of chondrites. Notably, the Nb/Ta trace element data when combined with textural observations may in the small Allende slices are negatively correlated with Tm/Er provide important additional insights into phase equilibria and ratios (0.16 to 0.26). At near-chondritic Tm/Er (ca. 0.16 [7]), the conditions of crystallization. mesured Nb/Ta in the Allende splits scatter around a value of 20, typical of the chondrite average. It has previously been argued that the elevated Tm/Er in many CV chondrites can be attributed to the presence of type II CAIs [5]. Low Nb/Ta ratios occasionally found in CV chondrites may reflect selective enrichment group II CAI. The co-variation between Nb/Ta and Tm/Er could imply that the bulk Earth exhibits a superchondritic Tm/Er, if it had a low Nb/Ta. This is clearly not the case, as the silicate Earth displays a Tm/Er that is not resolvable from that of CI-chondrites [7]. The Nb/Ta of the bulk Earth should therefore overlap the chondritic value and the Nb deficit in the Earth’s mantle reflects its siderophile behaviour.

[1] Münker et al. (2003) Science 301, 84-87. [2] Wade & Wood (2001) Nature 409, 75-78.[3] Palme & O’Neill (2003) Treatise on Figure 1. Contrasting REE profiles of amphiboles in ultramafic Geochemistry 2, 1-38, Elsevier, Oxford. [4] Corgne et al. (2008) rocks GCA 72, 574-589. [5] Stracke et al. (2012) GCA, in press.[6] Münker (2010) GCA 74, 7340-7361. [7] Pourmand et al. (2012) Chem Geol 291, 38-54.

Mineralogical Magazine | www.minersoc.org 2148 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts The fate of volcanic ash in marine Analog studies of brine sediments cryoenvironments in the Canadian RICHARD W. MURRAY1(*), JULIE C. SCHINDLBECK2, RACHEL P. high Arctic 1* 2 SCUDDER1, STEFFEN KUTTEROLF2 NADIA MYKYTCZUK , SUSAN TWINE , BOSWELL 3 2 2 1 WING , SIMON FOOTE , KELLY FULTON , CHARLES Department of Earth Sciences, Boston University, Boston, MA, 4 1 GREER , LYLE WHYTE USA, [email protected]; [email protected]. 2GEOMAR, Kiel, Germany, [email protected]; 1McGill University, Natural Resource Sciences, Montreal, Canada, [email protected] [email protected] (*presenting author); [email protected] Volcanic ash transported to the oceans is one of the main 2National Research Council Canada, Institute for Biological mechanisms by which terrigenous material and nutrients are Sciences, Ottawa, Canada, [email protected]; delivered to the deep sea. Alteration of volcanic glass in the ocean is [email protected]; [email protected] 3 an important component of marine biogeochemical cycling, with the McGill University, Earth and Planetary Sciences, Montreal, Canada, ash acting as a source and/or sink of many major and trace species. [email protected] 4 Ash in marine sediment also provides an important record of National Research Council Canada, Biotechnology Research explosive subduction zone volcanism. Discrete, visible ash layers are Institute, Montreal, Canada, [email protected]

common in the vicinity of subduction zones and have originated from The Canadian high Arctic offers several unique larger explosive eruptions at the volcanic arc. The chemistry and cryoenvironments including cold saline springs and extensive provenance of these visible ash layers are mostly well known and the permafrost that are working analogs to the conditions that are layers themselves facilitate direct or indirect dating and can therefore known, or are suspected, to exist on Mars, and potentially on other be used as marker horizons in marine sedimentology and astrobiological targets. In particular, fluvial features linked to past stratigraphy. Ash layers may also help estimate eruptive volumes, and and current processes on the surface of Mars suggest that liquid contribute to the chemistry of sediments and fluids in these regimes. brines near the surface exist and could have been a potential abode Normal grading and mineral enrichment at the base, glass shard for past or extant microbial life. Our recent research focused on morphology, as well as changes in ash color that are mostly detecting and examining microbial life in the unique cold correlated to variations in the chemistry of the primary glass, are saline/brine springs on Axel Heiberg Island. The microbiology and geochemistry of a habitat found within the Gypsum Hill (GH) spring features that are relatively easily recognized within the marine site will be presented, describing a constant circum-zero saline (7.5 sediment column. % salinity) habitat that is host to chemolithotrophic sulfur-oxidizing The qualitative and quantitative fate of discrete ash layers in bacterial filaments that flourish in the Arctic winter. The GH spring sedimentary sequences is only partly known. In theory, bioturbation site is a sulfide (25-100 ppm) and sulfate (2300-3700 mg/L) should destroy layers less than ~10 cm thick, yet well preserved abundant system serving as an analogue for the abundant sulfate layers of a few cm’s thickness are found even in bio-irrigated deposits and potential sulfate-rich brines on Mars. The GH springs deposits. By detailed geochemical and sedimentologic study, we here support viable, active (down to -10°C), and low diversity microbial quantify how the incorporation of the primary volcanic ash in marine communities dominated by Thiomicrospira spp.. Environmental sediments proceeds above ash layers and with distance from the meta-omic analyses (genomic, proteomic, transcriptomic) were source. We further discuss how ash is captured within the sediment aimed at uncovering insights into: a) the sulfur metabolizing column and recycled in subduction zones, and quantitatively address community; b) the diversity of core metabolic genes required to utilize essential nutrients (C, N) within this extreme environment; c) how ash layers compositionally affect the hosting sediment column. the pathways of energy utilization i.e. CH , H , sulfur; d) the Stratigraphic sampling of sequential 1-3 cm slices above 4 2 evolutionary and physiological traits required for microbial life in primary ash layers from offshore Central America show that densities this subzero, hypersaline cryoenvironment. The meta-analyses decrease due to lesser amounts of volcanic glass in the silty clay provided greater insight into the predominant Thiomicrospira marine sediments. The bulk rock chemistry reflects this gradation as metabolic enzymes expressed as part of the active microbial growth, well and can be quantified for single elements like U, Cr, Zr, V, and activity and adaptive traits during the late Arctic spring. In situ Pb, depending on the composition of the volcanic glass (mafic versus geochemical and isotopic analyses of the fractionation of multiple- felsic). The most important component for those changes is the <32 sulfur isotopes resulting from bacterial sulfur-metabolism vs. µm fraction, since ~14 wt% of this is still composed of volcanic abiotic isotope exchange illustrated the route of biogeochemical glass. Additionally, we see a decreasing frequency of ash layers with sulfur cycling and traced the formation and preservation of potential 33 34 36 increased distance from the source (e.g., 200 vs. 350 km). sulfur-based biosignatures (δ S, δ S and δ S stable isotopes). Quantification of this decrease will help establish a volcanic matter These studies demonstrate how complimentary molecular tools provide a functional link between microbial life and the correction factor for chemical and sedimentological parameters with geochemistry of their environments, how we can predict potential distance from source in subduction zone settings. biosignatures of microbial activity and illustrate unique traits linked to microbial survival within these brine cryoenvironments analogous to past or perhaps present conditions on Mars.

Mineralogical Magazine | www.minersoc.org 2149 Downloaded from http://pubs.geoscienceworld.org/minmag/article-pdf/76/6/2045/2920060/gsminmag.76.6.13-M.pdf by guest on 25 September 2021 Goldschmidt 2012 Conference Abstracts

Speciation of colloidal Fe in 26Al-26Mg and 10Be-10B systematics in terrestrial and marine environments CAIs from CO and CV chondrites 1* 1 2 using synchrotron X-ray KUNIHIRO MYOJO , TETSUYA YOKOYAMA , YUJI SANO , 2 3 spectroscopy and microscopy NAOTO TAKAHATA , AND NAOJI SUGIURA 1 1* 2 SATISH C.B MYNENI , BJORN P. VON DER HEYDEN , Department of Earth and Planetary Sciences, Tokyo Tech, 2 3 ALAKENDRA N. ROYCHOUDHURY , GUSTAVO A. MARTINEZ , [email protected] (* presenting author) 4 2 TOLEK TYLISZCZAK Atmosphere and Ocean Research Institute, The Univ. of Tokyo 3Department of Earth and Planetary Science, The Univ. of Tokyo 1Department of Geosciences, Princeton University,

2Department of Earth Sciences, Stellenbosch University, 3Department of Crops and Agroenvironmental Science, University of Fine-scale chronology is very important to discuss the dynamic Puerto Rico, evolution of the early solar system. Most of the critical events such 4Advanced Light Source, Lawrence Berkeley National Laboratory, as the formation of Ca, Al-rich inclusions (CAIs) and chondrules as *Corresponding author: [email protected] well as the accretion and early differentiation of planetary bodies have occurred within several Myr from the collapse of the molecular Iron is an essential element for all organisms, and it is a limiting nutrient in many parts of the oceans, including the unproductive cloud [1]. Short-lived chronometers are extremely useful to obtain regions of the Southern Ocean. Although Fe is not a common limiting highly-precise ages for a variety of extraterrestrial materials. In nutrient in terrestrial aquatic systems, Fe-minerals control the contrast to the most commonly used 26Al- 26Mg system, the 10Be-10B solubility and bioavailability of several nutrients and contaminants. chronometer has been rarely used because of the uncertainty if the While the dominant fraction of Fe occurs in the form of particulates 10 parent nuclide ( Be, T1/2=1.5 Myr) was homogeneously widespread in aquatic systems, its speciation and mineralogy are less well 10 10 understood. Here we show how Fe L-edge spectroscopy can be used in the solar nebula. In order to attest the usefulness of the Be- B 10 10 to study the speciation of iron in Fe-rich colloids. system, we have measured the Be- B ages in CAIs from two CO Previous studies have shown that Fe L-edge XANES spectra can chondrites (Moss and Felix) and one CV chondrite (NWA 2364) be used to identify the distribution of ferrous and ferric species coupled with their 26Al- 26Mg ages. CO chondrites are known to have accurately. Our study shows that the spectral features in the L -edge 3 chemical and mineral compositions similar to those in CV XANES spectra are sensitive not only to the oxidation state of Fe, but also to small changes in the structural environment of Fe. We use the chondrites. However, in-situ analysis of CAIs in CO chondrites has differences in energy and the spectral intensities of different Fe p-d been hindered by their relatively small mineral sizes compared to transitions to identify different iron oxides and oxyhydroxide phases. CV CAIs. In this study, fine-grained CAIs were measured by However, saturation and self-absorption problems, associated with NanoSIMS installed at the AORI, Univ. of Tokyo. transmission and fluorescence spectra of Fe-rich compounds The meteorite fragment containing CAIs was mounted in a resin, respectively, make positive identification of some of the Fe-phases difficult. and thoroughly polished. Because boron contamination is one of the Using the L-edge XANES spectroscopy studies on crystalline major problems in SIMS analysis for B-poor samples, we cleaned and amorphous Fe-oxides and oxyhydroxides, we conducted the polished sample surface with diluted HF prior to analysis. The speciation of Fe in the colloidal fraction of Southern Ocean water, mineral compositions of CAIs were observed by the SEM-EDX at and in several South African streams flowing into the Atlantic Ocean. the Univ. of Tokyo. We found some melilite grains (~50 Pm) in We find that the Fe in the riverine environments is present in the 10 10 ferric form, which is associated primarily with amorphous Fe-oxides. CAIs from Moss and Felix, which were subject to the Be- B and 26 26 These Fe-oxides also often exhibit Al substitution. The colloidal Fe- Al- Mg analyses using NanoSIMS. We found no melilite in CAIs speciation also changed dramatically with distance away from South from NWA 2364, and only the 26Al- 26Mg system was analyzed by Africa, and with different Fe-species in different frontal zones in the using hibonite grains. Southern Ocean. Characterization of colloidal Fe in freshwater lakes 10 11 We observed excess B/ B ratios in Moss CAIs, which yielded also indicates the abundance of amorphous Fe-oxide phases. 10 9 -3 Although crystalline iron oxides are found in several samples, an initial Be/ Be = (1.05±0.56)u10 . This is consistent with the -3 amorphous Fe-oxides appear to be much more abundant than the canonical value of Allende CAI, (1.04±0.09)u10 , within analytical crystalline phases, at least in the colloidal pool. A detailed discussion uncertainty [2]. In contrast, we were unable to obtained the initial of the method, and its application to the identification of different Fe- 10Be/9Be ratio for Felix CAI, because of the limited Be/B ratios in phases will be discussed. the melilite grains analyzed. We speculate that this is caused by B

contamination, because we cleaned the mounted Felix by relatively mild HF (0.01M), while Moss was cleaned by 0.1M HF. This implies that the removal of B contamination is critical for the measurement of 10Be-10B system in CAIs. For the 26Al- 26Mg system, all CAIs yielded initial 26Al/ 27Al ratios identical to the canonical value (5.11u10-5, [3]) within analytical uncertainties. This reinforces the usefullness of the 10Be-10B system as for a chronometer in the early solar system.

[1] Kleine, T. et al. (2009) GCA 73, 5150-5188. [2] McKeegan, K.D. and Davis, A.M. (2007) Treatise on Geochemistry 1, 1.16. [3] Jacobsen, B. et al. (2008) EPSL 272 353-364.

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