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Goldschmidt2013 Conference Abstracts 1239

U!–Pb and REE transfer across the capillary of large zircons in fringe: Impact of transient flow Estherville conditions and coarse-material lenses MAKIKO K. HABA1*, AKIRA YAMAGUCHI2, HIROYUKI C.M. HABERER1*, M. ROLLE1,2, O.A. CIRPKA1 KAGI1, KEISUKE NAGAO1 AND HIROSHI HIDAKA3 AND P. GRATHWOHL1 1Geochemical Research Center, University of Tokyo, 1Department of Geosciences, University of Tübingen, Bunkyo-ku, Tokyo 113-0033, Japan (correspondence: Hölderlinstraße 12, 72074 Tübingen, Germany [email protected]) (*correspondence: [email protected]) 2Antarctic Research Center, National Institute of 2Department of Civil & Environmental Engineering, Stanford Polar Research, Tachikawa, Tokyo 190-8518, Japan University, 473 Via Ortega, Stanford, CA 94305, USA. 3Department of Earth and Planetary Systems Science, Higashi- Hiroshima, Hiroshima 739-8526, Japan We performed quasi 2-D flow-through experiments at the laboratory bench-scale to investigate the impact of transient are composed of almost equal flow conditions and a coarse-material inclusion on oxygen proportions of silicates and Fe-Ni metal. The oxygen isotopic transfer from the unsaturated zone, across the capillary fringe compositions of the silicate parts of mesosiderites and HED (CF), to anoxic . The experimental setup consists of a (, , and ) indicate that flow-through chamber with inner dimensions of 80 cm ! 40 their parent bodies are same or located in the same region [1]. cm ! 0.5 cm (Fig. 1). Glass beads with two different ranges in However, an origin and formation of mesosiderites grain diameter were used as porous media. We applied a non- are still enigmatic, because they have experienced complex invasive optode technique to measure high-resolution vertical

metamorphism [2]. In this study, we report results of in situ O2-concentration profiles across the CF at several distances analyses of large zircons found in Estherville mesosiderite. from the inlet of the flow-through chamber. In addition, the An electron probe micro-analyser was used to identify a oxygen flux at the inlet and in the effluent of the flow-through zircon by elemental mappings of Zr and Si and for quantitative chamber was monitored over . of major elements. Crystallinity and structure of zircons were evaluated by Raman spectra and cathodoluminecence (CL) images, respectively. U–Pb and rare earth elements (REE) contents were analyzed using a sensitive high resolution ion micro-probe (SHRIMP). Two large zircons, 30 ! 100 µm and 100 ! 300 µm, were found. The CL images and Raman spectra indicate that the larger zircon consists of several domains. U and REE contents of the most part of the zircons are quite low compared with those in basaltic [3, 4]. However, the larger zircon has U- and REE-enriched area where U and REE contents are well Figure 1. Experimental setup with coarse-material inclusion. consistent with those in basaltic eucrites. The 207Pb–206Pb age The red dye (New Coccine) was used to visualize the flow of the U- and REE-enriched area is 4520 ± 14 Ma (2", n = 3), field. which is younger than zircons in basaltic eucrites [3] and Vaca Muerta (mesosiderite) [5]. These results suggest that the In homogeneous porous material, we quantified the effect original zircons in Estherville were similar to those in basaltic of different water table dynamics, i.e., slow and fast water

eucrites and could have recrystallized and overgrown during table fluctuations, on oxygen transfer. Enhanced O2-supply the metal-silicate mixing event. was observed in case of slow fluctuations due to pronounced partitioning from entrapped air. In case of a fast draining water [1] Clayton and Mayeda (1996) GCA 60, 1999–2017. [2] table the effect of specific yield has to be considered. The Wadhwa et al (2003) GCA 67, 5047–5069. [3] Misawa et al experiments performed in the heterogeneous system showed (2005) GCA 69, 5847–5861. [4] Haba et al (2013) LPSC 44, that oxygen transfer was significantly increased by the coarse- #1989. [5] Ireland and Wlotzka (1992) EPSL 109, 1–10. material inclusion due to flow focusing, the capillary barrier effect, and the presence of an air passage. These processes

contributed to the overall enhancement of O2-transfer through the CF to the underlying anoxic up to seven compared to what was observed in the homogeneous experimental setup.

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Influence of bacterial biomass on Campaign-style titanite U-Pb dating transport kinetics of phenanthrene by laser-ablation ICP: Implications N. HACHICHO*, A. MILTNER, L.Y. WICK for crustal flow, phase AND M. KÄSTNER transformations and titanite closure UFZ - Helmholtz Centre for Environmental Research Leipzig, 1 1 B.R HACKER A.R.C. KYLANDER-CLARK Germany (*correspondence: [email protected]) 2A 1 T.B. ANDERSEN AND J.M. COTTLE

Introduction 1Earth Science, University of California, Santa Barbara CA In soils, both pollutants and pollutant-degrading organisms 93106, USA ([email protected]) are heterogeneously distributed. For an efficient site 2Geosciences, Universitetet i Oslo, P.O. Box 1047 Blindern, remediation by biodegradation, transport of either the 0316 Oslo, Norway pollutant or the microorganisms is necessary. Earlier studies show the effect of fungal hyphae on the transport of both U-Pb dates of titanite from >150 samples of chemicals and bacteria by fungal highways or pipelines [1]. In quartzofeldspathic gneiss and leucosomes were measured our study we investigated how the presence of bacterial across the ultrahigh-pressure (UHP) Western Gneiss Region of biomass affects the diffusive transport of phenanthrene in Norway to understand deformation and metamorphism of aqueous solution in model systems (adapted from ref [2]) in during and exhumation. Titanite the laboratory. is unstable at pressures > 1.5 GPa, and, indeed, most yielded Phenanthrene Transport in Passive Dosing Systems post-UHP dates. A number of titanites sampled across large We studied the transport of phenanthrene from a silicone areas, however, have pre-UHP U-Pb dates, indicating that the ring loaded with phenanthrene (source) to a larger clean titanites survived their excursion to and return from silicone ring (sink). Both rings were placed in a vial depths metastably. This has three important implications. containing 1 ml of medium with or without bacteria not able to Titanite grains can remain closed to complete Pb loss during degrade phenanthrene at different cell densities. After xy regional metamorphism at temperatures as high as 750°C and hours, source, sink and medium were analysed separately for pressures as high as 3 GPa, implying that thermally mediated phenanthrene. volume diffusion was not the principal factor controlling resetting of the U-Pb system. Phase transformations in and Results and Discussion deformation of quartzofeldspathic rocks can be inhibited at the The presence of bacterial biomass increased the medium's same conditions. capacity for phenanthrene, but no difference in the phenanthrene contents in the source and the sink ring were found (Fig. 1). Further experiments with different soil bacteria with a range of surface properties and motilities will provide additional informationn to elucidate the role of bacterial biomass for the transport of chemicals in soil.

Figure 1: Phenanthrene distribution in passive dosing systems with biofilm of Arthrobacter chlorophenolicus A6 on the surface (A) and sterile agar (B).

[1] Banitz et al(2012) EnvironMicrobiolRep 2012, 1-8. [2]! Smith et al (2012) Environ. Sci. Technol. 46, 4852"4860.

www.minersoc.org DOI:10.1180/minmag.2013.077.5.8

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Interpretation of extreme diagenetic gradients in the settings with a new thermodynamic Eocene as a constraint on the activity model biological pump, atmospheric CO2 LAURA HAFFERT1, MATTHIAS HAECKEL1, VOLKER and the ocean’s major ion LIEBETRAU1 AND DIRK DE BEER2 composition 1 Helmholtz Centre for Ocean Research Kiel (GEOMAR), 1 1 1 MATHIS P. HAIN , DANIEL M. SIGMAN , J. A. HIGGINS , Germany (*correspondence: [email protected], 2 AND GERALD H. HAUG [email protected], [email protected]) 2Max Planck Institute for Marine Microbiology, Bremen, 1Princeton University, ([email protected]) Germany ([email protected]) 2ETH Zürich

A thermodynamic activity model (Pitzer approach) In the modern ocean surface the !13C of dissolved applicable to extreme environmental pTS-conditions (up to inorganic carbon (DIC) is high (13C-enriched) relative to deep 1000 bar, 200 °C and 6 M NaCl) coupled to an extensive , due to isotope fractionation during biological carbon database has been developed. The advantage of this fixation and the subsequent export of organic matter from the code is the incorporation of a comprehensive pressure surface to sequester 13C-deplete carbon at depth, the soft-tissue correction, as well as the flexibility on the choice of input component of the biological pump. In the Eocene, datasets, allowing fine-tuning of the model according the observations suggest that these isotope gradients where greater relevant pTS range. This code is then integrated into our than today, leading to the inference that the biological pump transport-reaction models, allowing for the interpretation of was stronger. However, this argument ignores the much extreme diagenetic settings, where regular seawater models greater ocean carbon inventory under high atmospheric CO2 fail. levels during the Eocene, which would dilute the biologically One such setting is the Mercator mud in the Gulf driven !13C gradients. Box model simulations indicate a of Cadiz, where the porewater profiles are characterised by a number of mechanisms to resolve this discrepancy, including strong salinity gradient in the upper 1-2 mbsf created by the changes in the ocean’s major ion composition and meridional mixing of upward advecting hypersaline (halite and gypsum temperature gradient. When using observational constraints saturated) mud volcano fluids and seawater (S=35). In such as temperature reconstructions, the depth of seafloor

addition, various types of authigenic gypsum (CaSO4#2H2O) carbonate preservation, fluid inclusion data and the absence of 13 and anhydrite (CaSO4) crystals, typical for evaporitic large-scale anoxia in the Eocene ocean, we find that the ! C environments, were found. We show, that here the precipation gradients are inconsistent with atmospheric CO2 levels greater

of authigenic CaSO4 is temperature driven and than 1200 ppm. In these Eocene scenarios, the ocean’s DIC is directly related to heat pulses that are typically occuring at similar to today, but pH and buffer capacity are much lower,

mud volcanoes. The composition of the CaSO4 mineral, in with implications for marine calcifying organisms. turn, is additionally controlled by the salinity gradient, raising the gypsum-anhydrite transition zone from >1 km to about 500 m sediment depth and during heat pulses (> 30 °C) even to within a few metres below the seafloor. Another application is the geochemistry of the sediment-

hosted natural CO2 seeps in the southern Okinawa Trough. At

the Swallow Chimney, located at 1380 mbsf, liquid CO2 and

CO2 hydrates are encountered in the top decimetres below the

seafloor. Here, the strong CO2 and concomitant pH gradient induce silicate and complete carbonate dissolution downcore. However, some carbonate is reprecipitated towards the seafloor again, as suggested by the radiogenic and stable Sr isotopy. Our thermodynamic model is used to test this hypothesis and to quantify the diagenetic processes occurring in this extreme geochemical environment.

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Complete simulation of deglacial Ocean chemistry before and after the 14 changes in atmospheric C/C: rise of atmospheric O2 Implications for ocean circulation I. HALEVY1 changes and CO2 release 1Weizmann Institute of Science, Rehovot 76100, Israel, 1 1 MATHIS P. HAIN , DANIEL M. SIGMAN 2 The tight coupling among the biogeochemical cycle of O AND GERALD H. HAUG 2 and those of the major redox-sensitive elements, such as C, Fe 1 Princeton University, ([email protected]) and S [1-3], implies that the rise in atmospheric O2 was likely 2ETH Zürich preceded, accompanied and followed by radical rearrangements in the cycles of these elements. Indeed, the

We present a new deglacial budget (production and decay) rise of O2 appears to be recorded in a variety of marine of 14C, the first to correctly predict the preindustrial global geochemical and isotopic records, especially those of Fe and activity of 14C. While 14C production change accounts for most S. Among others, these include traditional and mass- 14 14 of the overall decline in atmospheric C/C (i.e., $ Catm) since independent S isotope ratios [4,5], Fe isotope ratios [6],

the Last Glacial Maximum, it fails to explain the rapid detrital O2-sensitive mineral grains [7], and banded 14 observed $ Catm swings during deglaciation. We use a carbon formations [7]. Qualitative understanding of these records cycle model to separate the contribution of ocean CO2 release hinders insight into events that fundamentally reshaped 14 and circulation changes to the $ Catm , which together Earth’s surface environment. I have developed a chemically 14 yield an exceptional match to available terrestrial $ Catm data, detailed, spatially resolved model of the coupled marine 14 both in terms of overall deglacial $ Catm decline and biogeochemical cycles of S and Fe [8], which I use here to millennial scale variations. The previously hypothesized but provide quantitative constraints on ocean chemistry before and

not yet identified stagnant “mystery reservoir” in the ice age after the rise of O2.

ocean is not required in our simulations. Prior to the rise of O2, the main S reservoirs in the ocean are sulphate and thiosulphate, with concentrations up to ~60 and ~10 %M, respectively, consistent with recent constraints from mass-independent S isotopes in VMS deposits [9].

Elemental S particles (S8), which settle rapidly, reach only sub-nanomolar concentrations, but contribute much of the S flux to the sediments. A balance between riverine and hydrothermal supply of Fe2+ and its oxidation in the photic zone governs water-column Fe2+ concentrations, which do not exceed 5 %M, unlike suggestions that mineral solubility allowed Fe2+ concentrations as high as ~100 %M [7]. After the

rise of O2, sulphate becomes essentially the only marine S reservoir, and its concentration exceeds 1 mM. Sulphide concentrations in hydrothermal fluids exceed those of Fe, resulting in a decline of the hydrothermal Fe influx. Deposition of Fe (as Fe3+-hydroxides) becomes limited to near-shore environments. Among other topics, I will discuss the implications of these results to the records S isotope ratios, to metabolic S and Fe utilization, and to the observed Precambrian sedimentary record.

[1] Garrels and Lerman (1984) Am J Sci 284, 989. [2] Kump and Garrels (1986) Am J Sci 286, 337. [3] Hayes and Waldbauer (2006) Phil Trans Royal Soc B 361, 931. [4] Farquhar et al (2000) Science 289, 756. [5] Habicht et al (2002) Science 298, 2372. [6] Bekker et al (2010) Econ Geol 105, 467. [7] Holland (1984) The Chemical Evolution of the Atmosphere and Oceans. [8] Halevy (2013) Proc Natl Acad Sci USA 110, Early Edition. [9] Jamieson et al (2013) Nature Geo 6, 61.

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Densities of dilute coenzyme M Deep carbonate recycling and solutions to 0.80 MPa and 353.15 K metasomatic enrichment of the sub- A. S. HALL1 AND J. C. SEITZ1 * continental lithospheric mantle 1California State Univ. East Bay, Hayward, CA 94542 USA inferred from mantle xenoliths of the (*correspondence: [email protected]) East African Rift system

1* 1 2 Sodium 2-mercaptoethanesulfonate (C2H5NaO3S2), also S. A. HALLDÓRSSON , D. R. HILTON , P. SCARSI , T. 2 3 4 known as coenzyme M is a thiol that is essential to the process ABEBE , J. HOPP AND S. CHAKRABORTY of methanogenesis [1]. Coenzyme M is a cofactor involved in 1Scripps Institution of Oceanography, UCSD, La Jolla, USA methyl transfer reactions within methanogenic archaea. Given (*correspondense: [email protected]) that fossil evidence of methanogenic archaea may date back to 2IGG-CNR, Pisa, Italy 2.8 billion years [2], methanogenesis is likely an ancient 3Mineralogisches Institut, Universität Heidelberg, Germany metabolic process. Determining the thermodynamic properties 4Department of Chemistry, UCSD, La Jolla, USA of coenzyme M is essential for understanding the potential for its formation and reaction properties in high P-T environments The source region of the extensive magmatism driving the that host extremophiles and may have hosted the emergence of East Africa Rift System (EARS) is thought to involve one or life. more deep-seated mantle plumes with variable interactions The volumetric properties of dilute aqueous solutions of with overlying crust and, in particular, sub-continental coenzyme M (0.09966 m, 0.19950 m, 0.299921 m & 0.39815 lithospheric mantle (SCLM). To assess the role of SCLM in m) were obtained using an Anton Paar DMA 5000 vibrating modulating the volatile systematics of plume-related material, tube densimeter. Reproducibility of density measurements was -3 we report new results on the He-CO2-N2 isotope and relative <±0.00002 g·cm , exceeding propagated errors associated abundance of mantle xenoliths from throughout the EARS with uncertainty in the measurement of temperature, pressure, (Red Sea, Ethiopia, Kenya and Tanzania). and fluid concentration. Our analytical approach involves crushing mafic crystals Experimentally determined volumetric properties of to release CO2 and N2 trapped in fluid inclusions. This coenzyme M have not been previously reported in the approach was used on a suite of gas-rich xenoliths literature. Figure 1 shows partial molar volumes at infinite (dominantly pyroxenites, n=25). The xenoliths display a large dilution (V&) derived from fluid density data; it is clear that V& range in He-isotopes (5.9 to 13.9RA) but have a limited range is not a sensitive function of pressure in the range examined. of '13C values (-3.3 to +0.8‰), with only two xenoliths showing values lower than -2‰. '15N values range from -4.11 3 to +5.89‰ and CO2/ He and CO2/N2 ratios vary by orders of from 0.020 to 7.0 (x109) and 0.42 to ~3800, respectively. 13 3 The ' C-CO2/ He systematics of the xenoliths fall on a 2- 3 component mixing line where the low CO2/ He endmember is ~3x108, significantly lower than the DMM value (~2x109) This low ratio is consistent with low-end estimates of DMM 3 and the mean CO2/ He ratio of E- [1]. Thus, our new

data are consistent with enrichment of the SCLM by CO2-rich 3 8 13 mantle fluids with CO2/ He ratios >>3x10 and ' C ~0‰ - characteristics of recycled C from subducted carbonatitic Figure 1. Experimentally determined partial molar volumes at material. Such CO enrichments are also associated with infinite dilution of sodium 2-mercaptoethanesulfonate in 2 positive '15N values reinforcing the link between the aqueous solutions at 0.10-0.80 MPa and 293.15-353.15 K metasomatic fluid and subduction. Notably, xenoliths with from this study. Lines represent simple linear regression fits to high 3He/4He ratios (Afar) are also associated with '15N > - the data. The error bar represents the estimated uncertainty of 5‰, implying an important role for the deep-seated Afar ±1.0 cm3·mol-1. mantle plume in supplying recycled to the SCLM. Oxygen (in prep) will further enable us to [1] Balch & Wolfe (1979) J. Bacteriol. 137, 256-263. [2] constrain the nature of the recycled component. Brocks et al (1999) Science 285, 1033-1036. [1] Marty & Zimmerman (1999) GCA 63, 3619-3633.

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Volatile budgets and the late veneer The D/H ratio of the Deep Mantle ALEX N. HALLIDAY1* L. J. HALLIS*1,2, G. R. HUSS1,2, G. J. TAYLOR1,2, 2 1 K. NAGASHIMA , S.A. HALLDÓRSSON AND D.R. HITLON Department of Earth Sciences, University of Oxford, Oxford, OX1 3AN, U.K. (correspondence: [email protected]) 1University of Hawaii NASA Astrobiology Institute (*Correspondance: [email protected]) The late veneer hypothesis was proposed to explain the 2Hawai‘i Institute of Geophysics and Planetology, University budgets of refractory highly siderophile elements (HSEs) in of Hawaii, 1680 East-West Road, Room 503, Honolulu, the bulk silicate Earth (BSE) [1], which are too abundant to be HI 96822 in equilibrium with core-forming metallic liquids at low pressures. It was argued that they were added in chondritic The ratio of deuterium (2H) to (1H) in the Earth’s proportions after the core formed. It has also been proposed atmosphere has changed over geological time. The lighter that Earth’s volatiles were added as part of this veneer after hydrogen isotope (1H) is preferentially lost to space via Jeans the Moon forming Giant Impact [e.g. 2]. However, a late (thermal) escape, hence the atmosphere slowly becomes veneer does not explain Earth’s volatiles. The similarities in relatively enriched in deuterium and the 2H/1H ratio increases. moderately siderophile elements [3] and identical isotopic To measure the initial 2H/1H ratio of the Earth we must sample compositions of Si [4] and W [5] in the BSE and Moon a reservoir that has been totally isolated from surface provide evidence that terrestrial core formation and accretion processes. were limited following the Giant Impact [6]. For example, a Plate tectonics is known to drag surface water down into veneer of ordinary [7] would need to be <0.3±0.3% the upper mantle, but primitive areas of the lower mantle may to be consistent with W isotopes [6]. The H/C/N ratios of the be isolated from this circulation, hence uncontaminated by BSE (including all surface budgets) are strongly non surface hydrogen [1,2].!Certain mantle plumes, such as those chondritic. The estimated BSE H/N is 45 whereas carbonacous that formed the Hawaiian Islands, Iceland, and Baffin Island, chondrites have H/N <15 [8]. If Earth’s N was contributed by appear to have tapped into primitive, un-degassed, deep a CI chondritic veneer, more than 70% of the H would need to mantle sources, as evidenced by isotope ratios in rock be accreted from an additional source [8] requiring that major samples from these regions [2,3]. Therefore, 2H/1H analyses of portions of Earth’s volatiles predate any putative chondritic hydrous melt inclusions from erupted lavas at these sites could late veneer. Earth’s Ne, Ar and Kr are also too abundant to be give an accurate value for the Earth’s primordial water. explained with a chondritic veneer. Cometary ices do have However, oxygen isotope data suggest that some enriched Ar relative to major volatiles [9]. This would explain contamination from crustal material does occur in areas where Earth’s heavy noble gases but with amounts that are too small the crust is thick (e.g., Iceland and Baffin Island) [4]. to also explain the H, C and N [8]. A more likely scenario is Therefore, comparisons between oxygen and hydrogen isotope that after incorporation of early Solar components, Earth data should be made for samples from these areas. acquired most of its volatiles during main accretion. We are currently measuring the 2H/1H and 18O/16O ratios in This included noble gases, in roughly chondritic proportions, pristine melt inclusions and glasses from numerous with some fractionation from amorphous ices. A mechanism is Icelandic and Baffin Island basaltic units [5,6]. A number of required that will also fractionate the BSE’s H, C and N from these units contain some of the highest 3He/4He ratios each other, as well as deplete them relative to noble gases. currently measured worldwide, indicating a primitive deep Possibilities for this are losses to space and partitioning into mantle origin [2,6]. Others have lower 3He/4He ratios. Helium Earth’s core before and / or during the Giant Impact [8,10]. isotope variations will enable us to determine whether samples However, a volatile rich late veneer does not readily explain with higher (more primitive) helium isotope ratios correspond the data. to lower hydrogen isotope ratios.

[1] Chou (1978) Proc.Lun.SciConf. 9, 219–230. [2] Albarède [1] Williams and Hemley (2001) Annu. Rev. Earth . Sci. (2009) Nat. 461, 1227–1233. [3] Drake et al (1989) GCA 53, 29, 365-418. [2] Jackson et al (2010) Nature 466, 853-856.![3] 2101–2111. [4] Armytage et al (2012) GCA 77, 504–514. [5] Stuart et al (2003) Nature 424, 57-59. [4] Gurenko A. A. and Touboul et al (2007) Nat. 450, 1206–1209. [6] Halliday Chaussidon M. (2002) Earth. Planet. Sci. Lett. 205, 63-79.![5] (2008) Phil.Trans.R.S.L. A366, 4163–4181. [7] Walker et al Francis D. (1985) Contrib Mineral Petrol 89, 144-154. [6] (2002) GCA 66, 4187–4201. [8] Halliday (2013) GCA 105, Füri et al (2010) Geochim. Cosmochim. Acta 74, 3307-3332. 146–171. [9] Stern et al (2000) ApJ 544, L169-L172. [10] Hirschmann & Dasgupta (2009) ChemGeol 262, 4–16.

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Secular trends in the global ocean The oxidation state of in revealed through trace elements in basaltic sedimentary pyrite H.R. HALSE1,2,3*, A.J. BERRY1, P.F. SCHOFIELD2, J.F.W. 3 4 3 1 1 1 MOSSELMANS , K.O. KVASHNINA AND G. CIBIN J.A. HALPIN *, R.R. LARGE , L.V. DANYUSHEVSKY , V.V. MASLENNIKOV2, D. GREGORY1, T.W. LYONS3 AND 1Department of and Engineering, Imperial E. LOUNEJEVA1 College London, South Kensington, SW7 2AZ, UK (*correspondence: [email protected]) 1ARC CODES, University of Tasmania, Private Bag 126, 2Department of Earth Sciences, Natural History Museum, Hobart 7001, Australia (*correspondence: London, SW7 5BD, UK [email protected], [email protected], 3Diamond Light Source Ltd, Didcot, OX11 0DE, UK [email protected], [email protected], 4European Synchrotron Radiation Facility, Grenoble, France [email protected]) 2 Institute of Mineralogy, Urals Branch, Russia Recently erupted mid-ocean ridge (MORB) often ([email protected]) 3 exhibits disequilibria between the series of isotopes associated University of California, Riverside, CA, USA with the of U to Pb. This suggests rates of ([email protected]) melt trasport that are fast relative to the half-lives of the isotopes that are of anomalous abundance. Current U-series Sedimentary pyrite incorporates trace elements (TE) models are based on the assumption that U4+ is the only during growth at levels far beyond the host bulk rock, making oxidation state of U important during the generation, transport, it a potentially powerful proxy for seawater chemistry in the and differentiation of MORB magmas. However, if U5+ and/or marine rock record. We have developed a novel approach to U6+ were stable in the melt, then the chemical behaviour of U simultaneously quantify a suite of TE via LA-ICPMS in relative to Th4+ (and the other elements of the decay series) sedimentary pyrite from marine black shales, as a proxy for would vary significantly. chemical changes in palaeo-oceans. When our sedimentary High resolution U M -edge X-ray absorption near edge pyrite data is compared with published whole-rock data, we 4 structure (XANES) spectra were recorded for synthetic see similar trends. We show that the temporal TE curves for MORB and anorthite- eutectic compositions glasses 22 elements in sedimentary pyrite can be related to secular containing 0.5 wt % U O . Glasses were quenched from melts changes on Earth over 3.5 billion years. 3 8 equilibrated at 1400 °C and a range of oxygen fugacities (fO ) The Mo trend increases through time attributed to the 2 at one-atmosphere. The spectra were recorded in fluorescence significantly lower levels of oxygen in the atmosphere and mode at beamline ID26 of the European Synchrotron oceans in the early Earth system [1]. The effects of the Great Radiation Facility, which allows U M -edge spectra to be Oxidation Events are shown by the jumps in Mo at ~2500 Ma 4 acquired with an energy resolution that is not accessible at and 650 Ma, similar to what is seen in the bulk shale data. The most synchrotron facilities. In addition, U L -edge XANES broad Ni and Co trends are the opposite to Mo, attributed to 3 spectra were recorded for the same melt compositions in situ cooling upper mantle temperatures and decreased eruption of at magmatic temperatures at beamlines I18 and B18 of the komatiitic lavas from ~2700 Ma [2]. Pulses of elevated Ni and Diamond Light Source. Co correspond to episodes of Large Igneous Province The L - and M -edge spectra both vary systematically with eruptions, particularly obvious with the Siberian Traps at the 3 4 fO . The M spectra exhibit more complexity than the L Permian-Triassic boundary. Phanerozoic trends in all TE are 2 4 3 spectra and allow U5+ to be unambiguously identified as a far more cyclical. We identify Se as being particularly redox major component in both glass compositions, and U redox sensitive, which allows us to explore finer-scale fluctuations ratios to be quantified. The proportions of U4+, U5+, and U6+ through the Phanerozoic [3]. As our database expands in both vary systematically in the glasses. U5+ is a significant scope and temporal detail, this new approach in measuring TE oxidation state at the fO conditions of MORB generation, in sedimentary pyrite has exciting potential for chemical 2 with U5+/(U (where (U = U4+ + U5+ + U6+) varying from palaeo-ocean research. ~0.25 at the QFM (quartz-fayalite-magnetite) fO buffer to [1] Scott et al (2008) Nature 452, 456-459. [2] Konhauser et 2 ~0.1 at IW (iron-wüstite) +2. al (2009) Nature 458, 750-753. [3] Large et al (2013) Min. Mag., this volume.

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A multi-proxy record from a late The ortho-para ratio of H2O Neoproterozoic volcano-sedimentary desorbed from ice: Implications for basin, eastern Arabian Shield cometary coma GALEN P. HALVERSON1, GRANT M. COX1, T. HAMA*, A. KOUCHI AND N. WATANABE LUCIE HUBERT-THÉOU1, MARK SCHMITZ2, Inst. Low Temp. Sci., Hokkaido Univ., Japan JAMES W. HAGADORN3, PETER JOHNSON4, 1 1 ([email protected]) PIERRE SANSJOFRE , AND MARCUS KUNZMANN 1 Dept. of Earth & Planetary Sciences, McGill University, 3450 H2O contains two protons with nuclear spin of I=1/2, University St., Montreal QC, H3A0E8, CANADA. leading to two nuclear-spin isomers: the ortho (I=1, triplet, ([email protected]) parallel nuclear spin) and the para (I=0, singlet, antiparallel 2Dept. of Geosciences, Boise State University, Boise, ID nuclear spin) with statistical weights of 3 :1. The lowest

83725, U.S.A. energy level of ortho-H2O lies about 34 K above the lowest 3 Dept. of Earth Sciences, Denver Museum of Nature and para-level in the gas phase. Nuclear-spin temperature (Tspin) is Science, 2001 Colorado Blvd., Denver, CO 80205, U.S.A defined by a given ortho-para ratio (OPR), because the OPR 46016 SW Haines St., Portland, OR 97219, U.S.A. depends on temperature in local thermodynamic equilibrium.

Tspin of H2O has been observed in coma, and it has been

Small, middle to late Ediacaran intermontane basins occur derived to be ~30 K. Although the Tspin values have been in the northern and eastern Arabian shield. The Jibalah basins implicated as a temperature of cold grains at molecular are a subset of these basins that are minimally deformed and condensation or formation in a molecular cloud, or in the solar

concentrated along the Najd strike-slip fault system, where nebula, the correlation between Tspin and temperatures of ice at they likely originated as pull-apart basins during the late condensation, formation, and desorption is yet to be

stages of the East African orogeny. Whereas the Jibalah basins investigated. The present study measured the Tspin of H2O that all appear to share similar sedimentary basin evolution and are was thermally desorbed from amorphous solid water (ASW) at broadly the same age, the nature of the basin fill is highly the desorption temperature for cometary water ices, 150 K. variable. The 10x50 km Jifn Basin, along the northwestern The ASW samples were prepared at 8 K by several procedures

extent of the Halaban-Zarghat Fault Zone, has a carbonate-rich in an ultra-high vacuum chamber: H2O-vapor-deposited ASW

sedimentary succesion that was deposited between ~635 and and ASW produced by photolysis of CH4/O2 mixed solid. The 577 Ma. This succession includes a 340 m-thick shoaling sample solids were then heated to 150 K and the thermally

upward section of mixed cherty limestone and dolostone, desorbed H2O molecules were analyzed rovibrationally.

which overlies a basal, volcaniclastic conglomerate and in turn Desorbed H2O molecules from all ice samples were found to

is overlain by a thick interval of medium- to coarse-grained show Tspin almost at the statistical high-temperature limit,

arkosic sandstone. The carbonates are dominantly gravity flow indicating that Tspin of gaseous H2O molecules thermally deposits, transitioning upward into grainstones and heavily desorbed from ice does not reflect the surface temperature at

silicified microbial laminites—a facies that supplied many of which H2O molecules condense or form under laboratory the clasts to the deeper water gravity flow deposits. Felsic conditions. tuffs and tuffaceous siltstones, as much as 10 m-thick, occur throughout the succession. In several cases, these are directly [1] Hama, T. et al, (2011) ApJ, 738, L15 (5pp). overlain by a distinct sequence of organic-rich laminites, followed by rhythmites containing unusual, bubble-like (methane?) structures, and disrupted beds with evidence for fluid escape. We interpet the succession to record eutrophication of the water column following plinian volcanic eruptions. Here we report inorganic and organic C, O, S, and Sr isotopes, along with major and trace element abundances for the Jifn carbonates. We apply these proxies to evaluate the geochemical response in this small basin to massive input of volcanic material and to test its connection to the global ocean at a time of monumental environmental and biological change.

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IR spectra of thin film water The sub-Arctic upper mantle, from sandwiched between two mineral Jan Mayen to Molloy Fracture Zone plates CEDRIC HAMELIN1 AND ROLF BIRGER PEDERSEN1 M. HAMAMOTO*, M. KATSURA AND S. NAKASHIMA 1Centre for Geobiology, University of Bergen, Postboks 7800, NO-5020 Bergen, Norway. Department of Earth and Space Science, Osaka University,

Toyonaka, 560-0043, Japan (*corresppondence: In recent years, sub-kilometer scale studies have revealed [email protected]) that regional mantle heterogeneity is generally better preserved in oceanic where the melt supply is low. The Physicochemical behaviours of water sandwiched Mohns and Knipovich ridges in the Norwegian Greenland Sea between minerals are important to understand water-rock are among the slowest spreading mid-ocean ridges (15- interactions including rock quality degradation by water. In 17mm/yr) and present extremely low melting rates. This order to examine these properties, pure water sandwiched region is therefore a favorable location to study the different between two mineral plates was measured by transmission scales of geochemical mantle heterogeneity. infrared (IR) microspectroscopy. We present new Sr, Nd, Pb and Hf isotopic data from Pure water is sandwiched between two mineral plates samples collected along Mohns and Knipovich ridges, during (Fig.1) and its thickness is monitored by the absorbance at -1 2 4 differents cruises of the SUBMAR program (1999-2004). 1643.5 cm . The measurement area (100x100 µm ) is selected Our new dataset () 90 samples) together with published data to be occupied totally with water. This procedure is repeated (60 samples), represent a dense sampling of the sub-Arctic to obtain IR transmission spectra for different pure water upper mantle and allow us to look at regional variations as thicknesses. well as fine-scale, intra-segment, heterogeneity. A first order The measured spectra include effects of reflection at observation of geochemical variations along the ridge axis is a air/plate/water interfaces. These effects were removed and the progressively decreasing influence of the Jan Mayen absorption index k was calculated. (71°N) toward the north (73°N). The rather large geochemical variations measured in samples from the northern part of Figure 1 Pure water Mohns ridge (73-75°N) and along Knipovich ridge (75-78°N), sandwiched between two are unlikely related to hotspot-ridge interaction. The local mineral plates. upper mantle is influenced by the recent continental breakup and the presence of residual subcontinental lithosphere could

therefore contribute to the observed geochemical variability.

Previous study of this region have documented an atypical The extracted k spectra of thin film water sandwiched radiogenic *Hf values for a given *Nd [1], which appears to be between two CaF plates for different thicknesses from 20 nm 2 very comparable to the mantle signature discovered recently to 1 µm were successfully obtained with high signal to noise along the Mid-Atlantic Ridge near the Azores [2]. The origin ratio (Fig.2). These spectra match globally the k spetrum for of this mantle component is still a mater of debate. Our new different thicknesses within 5%.The k spectra of thin film dataset, together with published data from [1] is used to water between different mineral plates such as Al O and SiO 2 3 2 produce a detailed petrogenetic model for basalts erupted plates will be measured and compared. north of Jan Mayen and brings new constraints on the Figure 2 The structure and nature of upper mantle components present in absorption index k this area. spectra of pure water with different [1] Blichert-Toft, J. et al, 2005. Geochem. Geophys. Geosyst., thicknesses between 6(1): Q01E19. [2] Hamelin, C. et al, 2013. Chemical Geology, two CaF plates. 2 341(0): 128-139.

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Laser 40Ar/39Ar dating of Sensitivity boost for ICP-MS to supervolcanoes and super gold enhance isotope ratio determinations deposits along the trace of the MEIKE HAMESTER1* AND RENÉ CHEMNITZER1 Miocene Yellowstone Hotspot 1Bruker Daltonik GmbH, Fahrenheitstr. 4, 28359 Bremen, 1 2 1 Germany (*correspondence: W. HAMES *, M. BRUESEKE AND J. SAUNDERS [email protected]) 1Geology, Auburn Univ., Auburn, AL 36849, USA; 2Geology, Kansas State Univ., Manhattan, KS, 66506, USA. ICP-MS is a powerful technique for the determination of trace elements in various matrices. Beyond that ICP-MS is Early volcanism of the Yellowstone hotspot began at ca. able to determine isotope ratios with high accuracy and 16.5 Ma and produced abundant and extensive bimodal precision. In principle three intrumental ICP-MS solutions volcanics in northern Nevada and adjacent portions of Idaho exist: Quadrupole based ICP-MS, single collector magnetic and Utah along with some of earth’s richest gold deposits. sector field ICP-MS and multicollector magnetic sector field Within eruptive centers studied, volcanism tended to occur ICP-MS. General assumption is that precision and accuracy over a ~1.5 Ma interval. Tholeiitic flood basalts in this region, for isotope ratio measurements increases with complexity of that are typical of the earliest Columbia River Large Igneous technology used. The work will describe the achievements in Province (LIP) lavas, are typically the earliest volcanics, isotope ratio analysis by a new quadrupole based ICP-MS though they were extruded in multiple events that overlap (Bruker aurora Elite). Key characteristic is a very high ion rhyolitic magmatism. Although coarse plagioclase phenocrysts transmission achieved by an optimized interface, and a unique are conspicuously abundant in these basalts, they tend to be ion optical system with low chromatic and low in potassium content and have high amounts of inherited, spherical aberrations, which focuses ions into one focal point. extraneous argon, such that the most robust age dating results In result sensitivites of up to 4 Mio cps / ppb can be obtained, are for laser incremental heating of the basalt’s phenocryst- which exceeds sensitivities of magnetic sector field ICP-MS free, subophitic matrix. Single crystal laser fusion ages of significantly. The high sensitivity attainable allows utilization sanidine from the rhyolites are very precise, with some of the fast scanspeed and short integration times (0.1 msec) samples that yield a distribution of ages with a single mode without the limitation due to counting statistic. that is consistent with analytical uncertainty. However, The presentation will discuss all relevant instrumental sanidine from rhyolites in some eruptive centers yield more characteristics, such as: complex distributions of ages that are less than ~16.5 Ma, but that range beyond analytical uncertainty and comprise • Abundance sensitivity multiple age modes. Single crystal incremental heating • Scan speed analysis of sanidines from these more complex samples tend • Ion detection system to result in release spectra with plateau and indicate the • Plasma robustness samples are not affected by extraneous, non-atmospheric argon. We interpret that the duration of magmatism and high which are important to obtain highest isotope ratio geothermal gradients locally promoted isotopic closure at precision and accuracy. different times, in sanidine crystals of differing size and Finally results accomplished for e.g. and uranium effective diffusion dimension. Adularia is associated with isotope ratios and lead / uranium ratios will be shown. gold in many of the epithermal Au-Ag deposits and , and is commonly of sufficient grainsize to permit single crystal dating. 40Ar/39Ar fusion and plateau ages for adularia from many deposits in northern Nevada produce age distributions that are the same as the bimodal volcanics, however adularia from the Silver City district (southern Idaho) and associated Au-Ag deposits formed in one brief episode ~ 1 Ma after the earliest 16.5 Ma volcanics. In contrast with earlier models that invoke shallow crustal sources, the gold in these deposits is interpreted to have originated from a deep lithospheric or mantle source, and to have been transported by fluids to the epithermal systems as colloids.

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2-Methyl hopanoid production and Oxygen Minimum-Zone-like anoxygenic : A model conditions from the Early Cambrian cyanobacteria isolated from a of Chengjiang, South China proterozoic ocean analog E.U. HAMMARLUND1*, R.R. GAINES2, CHANGSHI QI3, 1 T.L. HAMILTON1, L.M. BIRD1, K.H. FREEMAN1 AND D.E. CANFIELD 1 AND J.L. MACALADY 1Nordic Center for Earth Evolution (NordCEE) and Institute of 1 Biology, University of Southern Denmark, 5230 Odense Department of Geosciences and Penn State Astrobiology M, Denmark (*corr: [email protected]) Research Center (PSARC), University Park, PA 16802 2Geology Department, Pomona College, Claremont CA USA (*correspondence [email protected]) 91711, USA 3Yunnan Key Laboratory for Palaeobiology, Yunnan Biomarkers recovered from ancient rocks provide University, Kunming 650091, China invaluable tools to reconstruct early Earth microbial ecosystems as well as providing clues about planetary redox The Cambrian explosion occurred between increases in evolution. Bacteriohopanepolyols (BHPs) or hopanoids are atmospheric oxygen concentration in the later Neoproterozoic Eon [1, 2] and during the Paleozoic [3, 4]. To further membrane lipids produced by many bacteria and are among constrain chemical conditions in the Early Cambrian ocean, a the most abundant and extractable organic compounds in multi-proxy geochemical approach was applied to two new ancient sedimentary rocks. Cyanobacteria are responsible for drill cores through a portion of the Early Cambrian succession oxygenation of the atmosphere and examining their presence of Yunnan, South China. Our results reveal a transition in in the rock record with specific biomarkers such as 2-methyl local ocean chemistry that is captured in both cores. Sulfidic BHPs can provide key clues regarding the rise of oxygen on conditions, which were well developed in the lower early Earth. However, the lack of a model cyanobacterium Yu’anshan Formation (members 1-2), pass through a capable of producing 2-MeBHPs as well as observations that transitional interval into oxic conditions in the upper part of other bacteria also produce these lipids has hindered our the Formation (member 4). In member 3, the interval bearing understanding of these biosignatures in ancient rocks. Here we exceptionally-preserved fossils of the Chengjiang biota (~520 demonstrate hopanoid production and anoxygenic Ma), a prominent positive isotope excursion occurs in photosynthesis in a cyanobacterium isolated from a both cores. This '15N excursion is noteworthy because it is Proterozoic ocean analog. We isolated a cyanobacterium that indicative of extensive denitrification under oxygen-depleted produces 2-MeBHPs from a red phototrophic mat in Little Salt conditions, and suggests that modern oxygen minimum-zone- Spring, a karst sinkhole in Florida with low levels of both like conditions were present. Results from Chengjiang suggest dissolved oxygen and sulfide. The hopanol content of the that the Cambrian radiation of the animals occurred in a phototrophic mat is high and rich in 2-methyl structures which relatively thin layer of shallow oxic waters that was sharply separated from toxic deep waters. are preserved in the organic-rich bottom sediments. Furthermore, we found the cyanobacterium is capable of [1] Fike, et al 2006. Nature 444, 744-747. [2] Canfield et al, primary productivity by anoxygenic photosynthesis. The 2007. Science 315, 92-95. [3] Bergman et al, 2004. Am. J. Sci. isolation of a cyanobacteria from an environment with a 304, 397-437. [4] Dahl et al, 2010. PNAS 107, 17911-17915. Proterozoic-ocean chemical composition that produces 2-

MeBHPs and is capable of anoyxgenic photosynthesis will greatly improve our understanding of the role of hopanoids in microbial physiology and ecology as well as the deposition of these biomarkers in the rock record.

Figure 1. A. Microbial biofilm collected from Little Salt Spring at 9 m water depth at sediment- water interface, human hand for scale. B. Culture bottle incubated in situ in the Little Salt Spring water column after inoculation with microbial biofilm from the sediment- water interface. C. Autofluorescence of cells due to the presence of phycoerythrin.

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Plant establishment in sulfide - Major melting on EL enstatite derived mine tailings stabilizes chondrite arsenic in situ despite promoting T. HAMMOUDA123*, M. BOYET123, B. MOINE234, arsenopyrite oxidation C. CARTIER123 AND J.L. DEVIDAL123 1Université Blaise Pascal, Laboratoire Magmas et Volcans, BP C. M. HAMMOND*, R. A. ROOT, R. M. MAIER 10448, F-16 63000 Clermont-Ferrand, France AND J. CHOROVER (*correspondence: University of Arizona, Tucson, AZ 85721, USA [email protected]) (*correspondance: [email protected]) 2CNRS, UMR 6524, LMV, F-63038 Clermont-Ferrand, France A compost-assisted phytostabilization strategy at the Iron 3IRD, R 163, LMV, F-63038 Clermont-Ferrand, France King Mine tailings in Arizona, USA aims to establish a self- 4 Laboratoire Magmas et Volcans, UMR CNRS 6524, sustaining vegetative cover as a low cost option to reduce Université Jean Monnet, 23 rue du Dr P. Michelon, human exposure to metal(loid) contaminants. Plant growth on F42023 23 SAINT-ETIENNE, CEDEX 02, FRANCE contaminated land reduces dispersion of particulate matter caused by erosion, but less is known regarding the effect of Chondrites are amongst the most primitive objects of the phytostabilization on subsurface metal(loid) speciation and solar system. Their constitutive represent either lability. Biogeochemical mechanisms controlling arsenic condensates, or interstellar dust that was once molten and speciation and lability were examined in a three year 1.5 ha quenched. Overall, chondrites are undifferentiated rocks that field trial in which dairy compost and irrigation water were did not experience core separation associated with planetary added to aid plant growth. Bench-scale chemical analyses formation. Some groups of chondrite are considered to were combined with synchrotron-based X-ray spectroscopic represent building blocks at the origin of , including the methods applied as a function of time, depth and specific Earth. Here we show that one group of enstatite chondrites treatment. Arsenic and iron K-edge X-ray absorption near- (EL) bears evidence for large scale melting, yet showing little edge structure (XANES) of untreated samples show oxidation (if any) sign of differentiation. We have compared the two of pyritic [FeS2, FeAsS] minerals to ferric (oxy)hydroxide groups (EH and EL). Differences between [e.g. ferrihydtite] and (oxy)hyroxide sulfates [e.g. jarosite-type EH and EL subtypes regarding both their bulk major element (III) + + 2+ minerals; XFe 3(OH)6(SO4)2, where X = K , H3O , Pb ] in compositions as well as their mineralogy have long been near-surface tailings, indicating an oxidation front penetrating recognized [1,2]. Here, we used in-situ, laser ablation the profile. Arsenic XANES indicate that both irrigation and inductively coupled plasma mass spectrometry (LA-ICP-MS) compost are associated with enhancement of sulfide oxidative analyses of minerals present in both enstatite chondrite weathering (Figure). Importantly, an increase in As lability subtypes (enstatite, and the two sulfides (FeS) and related to compost addition has not been observed. Sequential (CaS)). We show that each subgroup possesses a chemical extraction and Fe XAS results indicate that sulfide unique signature. EH chondrite trace element patterns are weathering may be associated with formation of an compatible with condensation signature, followed by ammonium oxalate-resistant Fe mineral phase, affecting the equilibration during metamorphism from type 3 to type 5. mobility of Fe-sorbed As in the tailings. They may thus be considered as primitive. On the contrary, EL chondrite patterns are suggestive of equilibrium during large scale melting on their parent body. They may therefore evidence melting processes that would yet essentially preserve the undifferentiated nature of their parent body, except in equilibrated types (EL5-6) wherein slight melt depletion is observed. Timescales for this melting should be long enough to allow for melt / crystal equilibration, but short enough to prevent metal / silicate separation. Alternatively, melting may have occurred in a low gravity field, either a small planetary body, or a molten disk following the collision of two large Figure 1. As K+ XANES linear combination fits of amended objects. and control field samples, fit with arsenopyrite and 2-line ferrihydrite. The binary fits, not normalized to unity, account [1] Keil (1968), J. Geophys. Res. 73, 6945-6976. [2] Wasson for 99-102% of the spectral features. & Keleymen (1988), Phil. Trans. R. Soc. Lond. A 325, 535- 544.

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Noble gas isotope studies of Ningwu Model-predicted and satellite- Ore District, Middle-Lower Yangtze retrieved tropospheric NO2 columns River polymetallic ore belt, East over East Asia China KYUNG M. HAN, CHUL H. SONG* AND SOJIN LEE DAN HAN1, CHAO DUAN1 AND YAN-HE LI1 School of Environmental Science and Engineering, Gwangju Institute of Science and Technolgoy (GIST), Gwangju, 1MRL Key Laboratory of Metallogeny and Mineral 500-712, Korea Assessment, Institute of Mineral Resources, Chinese ([email protected]; *correspondence: [email protected]) Academy of Geological Sciences, Beijing, China, 100037

In this study, we attempted to evaluate NO emission Different causes, such as the atmosphere, the Earth's crust, x fluxes over East Asia for the year of 2006, using CMAQ- mantle and sources of abundance and of the isotopic predicted and OMI-retrieved tropospheric NO columns. The composition is significantly different. Typical ratio of helium 2 3 4 -8 3 4 -5 two retrieved OMI products were taken from the Level-2 in the Earth's crust He/ He is 10 , He/ He value of 10 of DOMINO product version 2 (using KNMI algorithm) and mantle helium, difference of nearly 1000 times. from the Level-2 OMNO2 product version 2.1 (using NASA So helium argon and other noble gas isotope has become a algorithm). The two OMI products were well correlated research of crust-mantle interaction, the tracer mantle fluid (R=0.98 over Central East China). Also, averaging kernels mineralization and different ore-forming fluid mixed effective (AKs) taken from each OMI product were applied to the means and the most sensitive tracer. CMAQ-predicted NO columns (#CMAQ) for the comparison In this study, the concentration and isotopic compositions 2 analysis. The applied AK (i.e. AK retrieved from the of noble gases were measured in pyrite and magneti KNMI KNMI algorithm) to the #CMAQ showed seasonally good phenocrysts of 11 iron ore from Ningwu ore district Gaocun 3 4 3 correlations with the #OMI,KNMI (R=0.75, slope=0.92). Howere, and dongshan, He / He ratio is 1 Ra ~ 0.04 Ra,�Ra : He / 4 -6 the #CMAQ with the AK showed larger values than the He ratio of air 1.4�10 �, The He isotopic study shows, the NASA #OMI,NASA from the OMI observations despite of good environment of different 3He/4He ratio, showed there was no correlation coefficient (R=0.75) because the AK are With the same degree of deep fluid. Typical characteristics NASA vertically even larger by factors of approximate 2 – 10 than can be seen as the mantle fluid. AK over Central East China (CEC). The differences KNMI between the #CMAQ and #OMI using the NASA algorithm were

much larger than those using the KNMI algorithm during the winter episodes, whereas the differences were smaller using the NASA algorithm than those using the KNMI algorithm. In addition, this study investigated the large discrepancies

between CMAQ-predicted and OMI-retreived NO2 columns during the winter episodes in terms of the sesonal variations of

NOx source and heterogenous NOx sink. First, the seasonal

variation of the NOx emissions influenced greatly in the

tropospheric NO2 columns. For example, when non-seasonal factor were applied to the CMAQ model simulation, the #NO2,CMAQ decresed by 38% over CEC regions during winter, compared to those from the our baseline simulation. For the

latter, four parameterizations of gamma N2O5 were applied to the separete CMAQ model simulations during the cold seasons.

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Hf isotope evidence for continental Novel approaches to reconstructing lithosphere pollution of the cycling in methane seeps Asthenosphere near the L.G. HANCOCK1*, T.W. LYONS1, B.C. GILL2, Oceanographer Fracture Zone R.S. SHAPIRO3 AND S.M. BATES1 1 1 2 1 3 University of California Riverside, Riverside, CA, 92521 B. HANAN *, L. DOSSO , K. SAYIT , S. SHIREY 4 (*correspondence: [email protected]) AND J. BENDER 2Virginia Polytechnic Institute and State University, 1San Diego State University, San Diego, CA 92182-1020, Blacksburg, VA, 24061 USA (*correspondence:[email protected]) 3Chico State University, Chico, CA, 95929 2CNRS, IUEM, Ifremer, Plouzané 29280, France 3Carnegie Insitution, DTM, Washington, DC 20015, USA Methane ranks among the key greenhouse gases throughout 4University of North Carolina, Charlotte, NC 28223 Earth history, particularly under the generally more reducing conditions of the Precambrian. The mechanisms of methane Pb, Sr, and isotope data from a suite of basalts from ~35°, cycling have been studied extensively, but a complete ~0-10 miles north of the Oceanographer Transform (OFZ) are understanding of its role in the chemical and organismal interpreted as mixing between three chemically distnct mantle evolution of the ocean through time, including its closely sources [1]. The transform offsets the ridge right-laterally by coupled relationship to the sulfur cycle, are still largely 130 km and lies within the geochemical gradient attributed to unresolved. Modern and ancient seeps provide outstanding dispersion of the Azores plume and mixing with the depleted natural labs for studying coupled methane-sulfur cycles and upper mantle MORB source [2]. The third mantle their geochemical fingerprints. Many seep studies examine component’s isotope and geochemical characteristics suggest sulfide in pyrite, but pyrite formation in these settings is that portions of the mantle in the region contain detached typically limited by the availability of reactive iron and thus fragments of ancient sub-continental lithosphere. We have only captures the earliest diagenetic processes. In such cases, a analyzed a subset of the the samples previously analyzed for better way to track sulfur and its role in modulating methane Pb, Sr, and Nd [1] for Hf isotopes and high precision Pb production and consumption is by following the pathways of isotopes. dissolved sulfate, specifically using carbonate-associated sulfate or CAS. This study focuses on modern and ancient Figure 1: New seep sites marked by complex carbonate paragenesis and traces sulfur, carbon and oxygen isotopes to unravel ancient Hf isotope data methane cycling, its relationship to sulfur metabolic pathways for the OFZ and the preservational history of proxies during early to late region. Also burial. Our initial results suggest that coupled isotopic and shown are concentration measurements of CAS may closely track published data spatiotemporal variation in rates of microbial sulphate [3-5] for the reduction as coupled to anaerobic methane oxidation. These MAR and ultra- rates in ancient settings seem highly variable spatially and depleted MORB from temporally, as they are in modern seeps. CAS isotopic the Southeast Indian Ridge-AAD Pacific-Indian mantle relationships also reveal the relative patterns of sulfate boundary. reduction and sulfide oxidation, thus providing an essential backdrop for interpreting thiotrophic and methanotrophic Bifurcating trends bound the data and require at least 3 symbiosis among the seep-dwelling macrofauna. mantle components. An enriched C-like (low "Nd and "Hf), common to both trends, and two depleted components, one

DM like (high "Nd and intermediate "Hf), the other (very high

"Hf) similar to ultra-depleted MORB from the AAD, where the upper mantle is contaminated by continental material entrained during Gondwana rifting. The new OFZ Hf isotope data confirm the Pb and Nd isotope results [1] indicating pollution of the upper mantle MORB source by material derived from the continental lithosphere mantle, also advocated for the Azores plume [6]. This suggests that during plume-lithosphere interaction and rifting, accompanying the early opening of the Basin, fragments of refractory continental lithosphere mantle were incorporated into the OFZ MORB source.

[1] Shirey et al (1987) Nature325 217-223 [2] Schilling (1975) EPSL25 103-115 [3] Agranier et al (2005) EPSL238 96-109 [4] Debaille et al (2006) EPSL241 844-862 [5] Hamelin et al (2013) ChemGeol341 128-139 [6] Widom et al (1997) ChemGeol140 49–68.

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Along-arc geochemical and isotopic Oxygen fugacity in the Kaapvaal variations in Javanese volcanic rocks: cratonic lithosphere – Evidence from ‘Crustal’ versus ‘source’ Fe XANES measurements of Fe3+ in contamination at the Sunda arc, garnet from the Kimberley pipe Indonesia BRENDAN J. HANGER1*, GREGORY M. YAXLEY1, 1 2 1 2 ANDREW J. BERRY , VADIM S. KAMENETSKY , DAVID HEATHER HANDLEY , JANNE BLICHERT-TOFT , SIMON 3 3 1 3 4 PATERSON AND DARYL L. HOWARD TURNER , COLIN MACPHERSON , RALF GERTISSER 1Research School of Earth Sciences, The Australian National 1GEMOC, Department of Earth and Planetary Sciences, University, Canberra, ACT, 0200, Australia Macquarie University, Sydney, NSW 2109, Australia. (*correspondence: [email protected]) ([email protected]; [email protected]) 2 ARC Centre of Excellence in Ore Deposits, University of 2Laboratoire de Géologie de Lyon, Ecole Normale Superieure Tasmania, Hobart TAS 7001, Australia de Lyon, 69007 Lyon, France. ([email protected]) 3 3 Australian Synchrotron, Clayton VIC 3168, Australia Department of Earth Sciences, University of Durham,

Durham, UK. ([email protected]) 4 Oxygen fugacity is important in understanding the School of Physical and Geographical Sciences, Keele evolution of the cratonic lithosphere, but is more difficult to University, Keele, ST5 5BG, UK. determine than other variables (e.g. temperature and pressure). ([email protected]) 3+ It requires precise measurement of Fe /(Fe in garnet in peridotite xenoliths which until recently has been practically Through detailed studies of individual magmatic systems limited to the bulk technique Mössbauer spectroscopy. it is possible to identify and establish the relative importance However, new highly spatially resolved, in situ techniques and contributions of the various potential source components such as synchrotron-based Fe K-edge XANES [1] or the and differentiation processes that modify magmatic microprobe-based flank method [2] are enabling precise and composition, such as crustal contamination. Along-arc rapid determination of garnet Fe3+/(Fe. We have combined changes in lava geochemistry have long been recognised on XANES measurements with experimental calibrations of Java in the Sunda arc, Indonesia, but debate still prevails over oxybarometers applicable to peridotite [3] to determine the the cause of such variations and the relative importance of oxygen fugacities recorded in suites of garnet peridotite shallow (crustal) versus deep (subduction) contamination. We xenoliths from the Kimberley kimberlite, which sampled the present new Pb isotope data for Javanese volcanoes, which, Kaapvaal cratonic lithosphere. when combined with our recently published geochemical and The xenoliths examined are relatively fresh. Most contain radiogenic isotopic data of Javanese volcanic rocks and results lherzolitic garnet based upon the CaO-Cr O systematics [4], from other detailed geochemical and isotopic studies, 2 3 although two contain harzburgitic garnet. Thermobarometry elucidate the potential changing nature of the arc crust and its 207 204 206 204 reveals a pressure range of 2.5-4.5 GPa and a temperature control on lava chemistry. In Pb/ Pb- Pb/ Pb space the range of 880 – 1100 ºC. Fe XANES gave garnet Fe3+/(Fe Javanese volcanic data reveal two distinct trends which can be values from 0.04 and 0.07. ,logƒO [FMQ] varies between -0.46 related to either a strong control by crustal assimilation 2 and -2.40, with most samples falling between -2.0 and -2.4 at processes or source contamination by local sedimentary pressures from 3.5 to 4.2 GPa. The xenoliths show a general material on the down-going plate. Sr isotope ratios of volcanic trend of decreasing ,logƒO [FMQ] with depth, in broad rocks generally increase from West to Central Java, showing a 2 agreement with previous studies [5,6]. wide range within individual volcanic centres and broad

correlation with inferred crustal thickness, implying a strong, [1] Berry et al (2010) Chem. Geol. 278, 31-37. [2] Höfer and shallow-level control on isotopic composition. However, East Brey Am. Mineral. 92, 873-885. [3] Stagno et al (2013) Javanese volcanic rocks show significantly lower Sr and Pb Nature 493, 84-88. [4] Grutter et al (2004) Lithos 77, 841- isotopic ratios and extremely restricted isotopic variation at 857. [5] Woodland and Koch (2003) EPSL 214 295-310. individual volcanoes. Key trace element ratios combined with [6] Yaxley et al (2012) Lithos 140-141 142-151. radiogenic isotopic data of Javanese volcanoes reveal three distinct trends, which roughly equate with the geographical boundaries West, Central and East Java. These results provide evidence for major transitions in the crustal architecture of Java.

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Melt inclusions in mafic-ultramafic Sr isotope anomalies in meteorites: potassic volcanic rocks in British Uniform distribution of s- and r- Columbia, Canada: A record of the process Sr at the planetary scale transfer of PGE from mantle to crust ULRIK HANS1, THORSTEN KLEINE2, CHRISTOPH in porphyry settings BURKHARDT1 AND BERNARD BOURDON3 1 1 2 Institute of Geochemistry and Petrology, ETH Zurich, JACOB J. HANLEY AND ZOLTAN ZAJACZ Switzerland (*correspondence [email protected]) 1Dept. Geology, Saint Mary’s University, Halifax, Canada 2Institut für Planetologie, Westfälische Wilhelms-Universität

(*correspondence: [email protected]) Münster, Germany 2IGP, ETH Zürich, Zürich, Switzerland 3Ecole Normale Supérieure de Lyon, UCBL and CNRS, France Mafic-ultramafic subvolcanic intrusions composed of alkalic basalt are spatially/temporally associated with many Planetary-scale nucleosynthetic anomalies have been alkalic Cu-Au deposits in the Canadian Cordillera that contain identified for various refractory elements, indicating that the resources of platinum-group elements (PGE). In the Afton protoplanetary disk was not entirely mixed with respect to porphyry deposit, we have investigated melt inclusions stellar sources or that thermal processing of solid material was preserved within leucite-clinopyroxene-olivine(>Fo90)-rich uneven. In this study we re-address the presence of planetary- basalts (18-22 wt% MgO) in order to understand their scale 84Sr/86Sr anomalies. Several bulk chondrites, eucrites, relationship to porphyry evolution/metal tenor. as well as Ca-Al-rich inclusions (CAI) from the CV3 Olivine-melt and melt inclusion microthermometry for chondrite Allende were analyzed using the Thermo Triton primary inclusions in growth zones in clinopyroxene TIMS at ETH Zürich in a dynamic acquisition mode. In primocrysts constrain the liquidus T of the basalt between contrast to static measurements (as used in previous studies 1370-1520oC. However more evolved liquids, trapped as [1]) no difference in 84Sr/86Sr ratios between the NBS987 secondary inclusions in , were likely trapped as low standard and terrestrial rock standards was found. as ~900oC and at low pressure. Shallow depths of Furthermore, with the exception of CV and CM chondrites all emplacement for the basalt sills and dykes are confirmed by bulk meteorites show within uncertainty a uniform and pepperite textures indicating interaction of the bodies terrestrial 84Sr/86Sr. The anomaly in the CM chondrite could be with wet volcanic sediments, sandstones, and mudstones. The due to incomplete dissolution of presolar SiC grains, while the Cr content of early melt inclusions (Cr-in-melt anomalies in Allende can be attributed to the high abundance oxybarometry[1]), determined by laser ablation ICP-MS, and of CAI which show 84Sr/86Sr anomalies of up to 1.3", most chromian -olivine oxybarometry indicate that the liquids likely due to an excess in r-process Sr. Thus, our results do not were relatively oxidized (~FMQ+1.5). confirm the planetary-scale Sr isotope heterogeneity reported Melt inclusion analysis is essential to characterize the trace in an earlier study. Instead they indicate that overall, the Sr element chemistry of the basalts because the intrusions are isotope composition of the solar nebula prior to planetary cumulates containing non-cotectic proportions of olivine and accretion was rather homogeneous, which is essential to pyroxene, and the groundmass was extensively establish the Rb-Sr chronology of volatile element depletion in hydrothermally altered by the adjacent porphyry stock. Early the early solar system. melts are most similar to high Ca-Mg, high K2O, silica- undersaturated arc ankaramites and their differentiates, formed [1] Moynier et al, Astrophys. J.. 758:45 ,(2012) by partial melting of amphibole or clinopyroxene-rich cumulates in sub-arc lithospheric mantle or lower crust. The early melt inclusions are highly enriched in PGE, containing up to ~480 ppb Pd and a high Pd/Pt ratio (~10-20), identical to that of porphyry-stage ore in the deposit. The exact mechanism by which this high Pd/Pt was inherited by the porphyry magma (i.e., fractional crystallization, mixing with/contamination by crustal rocks/melts) is being evaluated.

[1] J.Brenan (2012) personal communication

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Widespread production of Venus crustal plateaus as an analog extracellular superoxide by for Archean cratons and SCLM heterotrophic bacteria VICKI L. HANSEN * C.M. HANSEL1*, J.M. DIAZ2, B.M. VOELKER3, Dept. of Geol. Sciences, University of Minnesota, Duluth MN P.F. ANDEER1 AND T. ZHANG1 55812 USA; (*correspondence: [email protected]) 1 Marine Chemistry and Geochemistry Department, Woods A hypothesis is presented suggesting that Venus’ ancient Hole Oceanographic Institution, Woods Hole, MA 02543, crustal plateaus and their mantle roots represent analogs for U.S.A. (*correspondance: [email protected]) 2 Archean cratons and their underlying subcontinental Biology Department, Woods Hole Oceanographic Institution, lithospheric mantle (SCLM). Crustal plateaus (~1500-2500 Woods Hole, MA 02543, U.S.A. 3 km diameter) are quasicircular features that rise 0.5-4.0 km Department of Chemistry and Geochemistry, Colorado above Venus’ lowlands, supported by low density isostatic School of Mines, Golden, CO 80401, U.S.A. roots, and host a distinctive structural fabric called ribbon- Superoxide, a reactive oxygen species (ROS), is a tessera terrain (RTT). RTT also occurs as arcuate-shaped powerful and versatile reactant that is toxic to living exposures in the lowlands, widely interpeted as ‘collapsed’ or organisms and can dramatically alter the geochemical rootless crustal plateaus. Crustal plateaus and RTT inliers landscape through a myriad of redox reactions. (A)biotic represent Venus’ oldest preserved features and surfaces. RTT reactions that are directly or indirectly coupled to sunlight fabrics and their host crustal plateaus are postulated to have have been the only recognized sources of environmentally formed as the solidified ‘scum’ of huge lava ponds, formed by relevant ROS. Phytoplankton, for instance, have previously large (>25 km diameter) impacts with ancient thin been shown to produce ROS, yet their abundance and lithosphere. pierced the lithosphere, leading to distribution in nature is fundamentally constrained by sunlight. massive partial melting in the upper mantle. Melt rose to form Thus, although ROS production has been frequently observed huge surface ponds, burying bolide scars; high-Mg depleted in the deep ocean and at night, superoxide and other ROS are mantle melt residuum formed a robust buoyant root, leading to regarded as pertinent only in sunlit systems, which represent plateau formation, and long-term stablity. The roots of merely ~5% of the habitable environment on Earth. lowland RTT were removed, likely due to mantle convection. Here we show that common and abundant heterotrophic On Earth, Archean cratons comprise granite-greenstone bacteria are a vast unrecognized source of ROS. We analyzed terrains (GGTs) and associated high-Mg SCLM. Like crustal extracellular superoxide production by a broad range of plateaus, GGTs are unique—lacking contemporary analogs— ecologically and phylogenetically diverse heterotrophic and they have been remarkably stable since formation; thus, bacteria using a high sensitivity flow-through they too record ancient geologic processes of their host. chemiluminescence approach. Superoxide production was Recent studies indicate that Late Heavy Bombardment detected by 27 of 30 environmentally common isolates. Rates (LHB) on Earth lasted through the Archean. Therefore, like of superoxide production normalized to the proportion of Venus, early Earth’s thin lithosphere would have been metabolically active cells varied a few orders of magnitude, bombarded by numerous large bolides (>25 km), with a likely between 0.02 ± 0.02 and 19.4 ± 5.2 amol cell-1 hr-1. Although similar first-order response, resulting in massive partial cell-normalized rates of superoxide production by melting of the mantle, escape of high-Mg melt to the surface heterotrophic bacteria are lower than those measured (komatiites), and formation of a high-Mg residuum root, previously for marine phytoplankton, rates normalized to cell which protected the new-formed crustal features from younger surface area are comparable to, and in several cases greater planetary processes. GTTs that survived retain their roots; than, those of phytoplankton. Superoxide production by a GTTs that lost their roots were likely accreted to stable GTTs model bacterium within the ubiquitous Roseobacter clade or recycled by younger plate tectonic processes. The involves an extracellular NADH oxidoreductase, suggesting a hypothesis suggests that Venus’ crustal plateaus and Earth’s surprising homology with eukaryotes. GGTs both formed during LHB, when both of these young hot Our discovery therefore introduces the likelihood of ROS planets had relatively thin lithosphere, and record a unique era cycling in ~95% of the global habitat that is untouched by in the evolution of these sister planets. Large bolides light, a paradigm shift which will certainly transform our punctured the thin lithospheres, which were strong enough to understanding of the geochemistry, ecology, and health of a support the products of massive mantle partial melt; the high- wide range of modern and ancient environments. Mg melt residuum roots protected these unique regions from younger planetary processes on both planets.

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Numerical modeling of iron-corrosion Large geochemical variations in and interaction with bentonite submarine HIMU basalts C. HANSMEIER1, G. BRACKE2 AND B.REICHERT3 T. HANYU1*, L. DOSSO2, O. ISHIZUKA3, K. TANI1, 4 5 6 1 1,2 B.B. HANAN , C. ADAM , S. NAKAI , R. SENDA , Q. Department of Final Disposal, GRS mbH, Schwertnergasse 1 7 1, 50667 Cologne, Germany, CHANG , AND Y. TATSUMI 1 2 ( [email protected], [email protected]) 1IFREE, Japan Agency for Marine-Earth Science and 3 Steinmann-Institute, Department Hydrogeology, Nussallee 8, Technology, Yokosuka 237-0061, Japan 53115 Bonn, Germany, ([email protected]) (*presenting author: [email protected]) 2CNRS, IUEM, Ifremer, Plouzané 29280, France In deep geological repositories, bentonite is preferred as a 3Geological Survey of Japan, AIST, Tsukuba 305-8567, Japan possible Engineered Barrier (EB) to isolate the High Level 4San Diego State University, San Diego CA 92182-1020, USA Waste (HLW) from the biosphere. Over time, the iron canister 5Universidade de Évora, Évora 7002-554, Portugal of the HLW corrodes under anaerobic conditions and 6Earthquake Research Institute, The University of Tokyo, interactions between the EB and the corrosion products of the Tokyo 113-0032, Japan iron canister modify the properties of the bentonite. Besides, 7Kobe University, Kobe 657-8501, Japan formation water in the host rock (Opalinus clay) affects the bentonite, too. We report the geochemical compositions of submarine The aim is to calculate changes in porewater chemistry, basalts collected by a manned submersible from Rurutu, mineral dissolution and precipitation as well as its effects on Tubuai, and Raivavae in the Austral Islands, French Polynesia, permeability and porosity changes on process level to assess where subaerial basalts exhibit robust HIMU isotopic the long term behavior. Cation exchange and surface signatures. The 40Ar/39Ar ages of the submarine basalts overlap complexation are not considered in this model. The system is with those of the subaerial basalts with the exception of one modeled as a 1D model for a timescale of 10.000 years. Due sample from Tubuai. While the major element compositions to low permeabilities of both bentonite and clay the mass are similar between the submarine and subaerial basalts for transport entirely takes place by diffusion, leading to small each island, the submarine basalts exhibit much larger changes of constituents only. Precipitation of corrosion variations in Pb, Sr, Nd, and Hf isotopic compositions than products decreases the porosity of the system. For calculations those previously reported in subaerial basalts. The submarine the code TOUGHREACT [1] is used with PetraSim [2] as user basalts with less-radiogenic Pb isotopes show systematically interface. TOUGHREACT adds reactive geochemistry to the lower abundances in highly incompatible elements than the multi-phase flow code TOUGH2 [3]. basalts with radiogenic Pb isotopes. The overall geochemical variations are best explained by a two-component mixing [1] Xu, T., Sonnenthal, E., Spycher, N., Pruess, K.: between the melt derived from the HIMU reservoir on one TOUGHREACT User’s Guide: A Simulation Program for hand and the melt from the depleted asthenospheric mantle Non-isothermal Multiphase reactive Geochemical Transport in entrained by an upwelling plume on the other. The present and Variably Saturated Geologic Media, 2006, LBNL, UC: compiled data demonstrate that the HIMU reservoir has Berkeley, California, USA. [2] Thunderhead Engineering: uniquely low 176Hf/177Hf for a given 143Nd/144Nd, suggesting it PetraSim 5, User Manual, 2005, Manhattan, Kansas, USA. [3] being formed by subduction of an ancient slab. Moreover, the Pruess, K.: TOUGH2: A general purpose numerical simulator Nd/Hf ratios of the HIMU basalts, together with the for multiphase fluid flow, 1990, LBNL, UC: Berkeley, curvilinear aspect of the 143Nd/144Nd–176Hf/177Hf mixing trend, California, USA. suggest higher Nd/Hf for the HIMU reservoir than for the depleted mantle component. Such elevated Nd/Hf of the HIMU reservoir could reflect metasomatic enrichment processes of the mantle by a partial melt derived from subducted material during reservoir formation.

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Impact of phenanthrene on the Alkenone record of the 19 years long formation of microbial habitats in soil time-series sediment trap samples J. HANZEL* AND K. U. TOTSCHE collected at central subarctic North Chair of Hydrogeology, Institute for Geosciences, Friedrich Pacific and Bering Sea Schiller University Jena, Burgweg 11, 07749 Jena, 1* 2 1 NAOMI HARADA , KOZO TAKAHASHI , MIYAKO SATO , Germany (*correspondence: [email protected]) 1 3 JONAOTARO ONODERA , HIROJI ONISHI

Recent studies reveal that there is a strong interplay 1Japan Agency for Marine-Earth Science and Technology between the physical soil structure and the activity of soil (JAMSTEC), Yokosuka, Japan, microorganisms [1, 2, 3]. Yet, a quantitative understanding of (*Correspondence: [email protected]) this feedback loop and their consequences for the soil 2Hokusei Gakuen University, Japan functions remain speculative. Two-layer soil columns packed 3Hokkaido University, Japan with soil material and spiked with phenanthrene in its upper layer will be used after forced-gradient transport experiment The subarctic North Pacific including the Bering Sea is the has been performed. Thin sections prepared from soil area that efficient biological pump works [1]. According to the aggregates taken from different depths of the column will be global compilation of sediment trap experiment [2], the analyzed to examine the impact of phenanthrene on the subarctic North Pacific including the Bering Sea represents formation of microbial growth habitats in soil. Epifluorescent that biogenic opal/CaCO3 ratios of settling particles is the microscopy will be applied to identify growth habits of DAPI- highest in the world. The time-series observation of settling stained cells of soil microorganisms and to determine their particles is valuable to understand the changes in the function abundance and spatial distribution in the soil column. The of subarctic biological pump associated with climate changes. microbial habitats will be examined by scanning electron Thus, to understand characteristics of prymary fluxes of microscope (SEM) and the results will be compared with the biogenic particles, plankton assemblages and to detect the data obtained from non-spiked controls, where soil interfaces environmental variation and changes in low trophic level will be characterize to elucidate how the activity of ecosystem associated with current climate changes, settling phenanthrene degrading soil microorganisms alters the particulate samples were collected for 19 years by sediment physicochemical soil properties. Such knowledge will trap mooring system at St. SA (49°N, 174°W, water depth contribute to a mechanistic understanding of the interactions 5406m) in the central subarctic North Pacific and at St. AB between soil structure, habitat and microbial activity and may (53°30’N, 177°W, water depth 3788m) in the central Bering ultimately help to better understand soil formation and the Sea from 1990 to 2010 [3]. The diatom and radioralia having functions of a soil. opal test were predominant components throughout the 19 years at both stations. The CaCO3 was the secondly dominant [1] Young and Crawford (1994) Science 304, 1634-1637. [2] component of settling particles [3]. The CaCO3 was composed Crawford et al (2012) J R Soc Interface, doi: of calcareous nannoplanktons and micro zooplankton. 10.1097/rsif.2011.0669. [3] Hanzel and Totsche, submitted. Coccolithus pelagicus and Eminiania huxleyi were two major species. The relative abundance of C. pelagicus and E. huxleyi were average 55% and 42% to the total calcareous nannoplanktons [4]. Alkenone flux increased in August, September, October and November at both sites. In the presenation, more details about the alkenone flux will be shown. We will discuss the seasonal and annual changes in alkenone fluxes comparing with other components.

[1]Takahashi et al. (2002) Prog. Oceanogr. 55, 95-112. [2]Honjo et al. (2008) Prog. Oceanogr. 76, 217-285. [3]Takahashi et al. (2012) Memories of the Faculty of Science, Kyushu University. Series D, Earth and planetary sciences, 32(4), 1-38. [4]Tsutsui et al. (2013) Deep-Sea Res. II (in press).

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CO2 degassing in a haplo-basaltic Simulating the role of extra-cellular magma: An experimental approach DNA in cellular adhesion 1-3 1-3 4 1 1 M. HARDIAGON , D. LAPORTE , Y. MORIZET , JOHN H. HARDING* , COLIN L. FREEMAN , AND A. PROVOST1-3 RACHEL WALTON2, STEVEN BANWART2,3, 4 5 1 STEVE ROLFE AND MARK GEOGHEGAN Clermont Université, Université Blaise Pascal, Laboratoire Magmas et Volcans, BP 10448, 63000 Clermont-Ferrand 1Department of Materials Science and Engineering, 2 CNRS, UMR 6524, LMV, 63038 Clermont-Ferrand University of Sheffield, Sir Robert Hadfield Building, 3 IRD, R 163, LMV, 63038 Clermont-Ferrand Mappin Street, Sheffield, S1 3JD, UK Correspondence: [email protected] 2Department of Civil Engineering, Univeristy of Sheffield, Sir 4 Département de Planétologie et Géodynamique, Université Frederick Mappin Building, Mappin Street, Sheffield, S1 de Nantes, 2 rue de la Houssinière, 44300 Nantes, France 3JD, UK 3Kroto Research Institute, University of Sheffield, North

Basaltic magmas carry huge amounts of volatiles (CO2, Campus, University of Sheffield, Broad Lane, Sheffield,

H2O, SO2) from their sources in the upper mantle up to the S3 7HQ, UK Earth surface. The dynamics and efficiency of basalt 4Department of Animal and Plant Sciences, Alfred Denny degassing are fundamental parameters for eruption dynamics, Building, University of Sheffield, Western Bank, the environmental impact of volcanism, and the global cycle Sheffield, S10 2TN, UK of volatile elements. Some models of basalt ascent and 5The Department of Physics and , Hicks Building, degassing are purely based on equilibrium solubility laws Hounsfield Road, Sheffield, S3 7RH, UK while others take into account disequilibrium processes such as bubble nucleation and growth (e.g. [1]). Attempts to Bacteria produce a vast range of mineral deposits within integrate these disequilibrium processes are hampered, the earth and are involved in the degradation of many however, by the lack of experimental data on major variables, materials. Experimental studies have demonstrated that extra-

such as the basalt-CO2 surface tension. celluar DNA (eDNA) is a major component of the extra-

We investigated CO2 degassing in an ascending basaltic cellular polymeric substance used to bind the bacteria to melt by performing decompression experiments in a piston- surfaces [1]. Understanding the mechanisms of eDNA cylinder apparatus. Series of experiments were run at a attachment is necessary to understand biofilm development. constant decompression rate and quenched at different We have explored the mechanisms of attachment using pressures in order to characterize the kinetics of bubble molecular dynamics simulations that provide atomic-scale nucleation and growth. The main parameters of interest are the detail to analyse the interactions. We consider how eDNA

bubble nucleation pressure PN, the critical supersaturation binds at amorphous silica surfaces which provides an analogue

pressure ,PN (= PSAT - PN, where PSAT is the volatile saturation to many geological and experimental systems. A range of pressure), the bubble number density, the bubble size different solvated cations is simulated to enable us to look at

distribution and the residual CO2 supersaturation in the melt. their effect on both the space-charge layer and on localised A CMAS-Na basaltic glass cylinder was loaded along with bonding. We discuss the implications of these results for

silver oxalate powder (the source of CO2) into a Pt container. bacterial attachment and the building of DNA based scaffolds

The melt was first saturated with CO2 at 2 GPa-1500°C and on mineral surfaces comparing them with current experimental then decompressed at 1 MPa/s. Homogeneous bubble work where possible. nucleation was observed in the experiment quenched at 1.2 GPa, but not in the ones quenched above 1.5 GPa. This yields [1] J.S. Andrews, S.A. Rolfe, W.E. Huang, J.D. Scholes, S.A. a ,P for CO bubbles in basalt of 0.5 to 0.8 GPa, thus larger N 2 Banwart, (2010) Environmental Microbiology 12(9), 2496– than the values reported in the literature (0.2 GPa [2] or 0.4- 2507 0.5 GPa [1]). Quantification of CO2 in the decompressed quenched glasses is in progress to quantify the residual volatile supersaturation.

[1] Bottinga and Javoy (1990) Chem. Geol., 81: 225-270. [2] Lensky et al (2006) Earth Planet. Sci. Lett. 245: 278–288.

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A record of paleoproterozoic surface Dark organic matter in permanently ocean redox from iodine-to-calcium shadowed craters on ratios E. R. HARJU1, D. A. PAIGE1*, M. A. SIEGLER2, 3 4 1 2 M. L. DELITSKY , D. SCHRIVER DALTON S. HARDISTY *, ZUNLI LU , NOAH J. PLANAVSKY3, ANDREY BEKKER4, XIAOLI ZHOU2, 1Department of Earth and Space Sciences, University of TIMOTHY W. LYONS1 California, Los Angeles, CA 90095, USA (*correspondence: [email protected]) 1University of California, Riverside, USA 2Jet Propulsion Laboratory, Pasadena, CA 91109, USA (*correspondence: [email protected]) 3 2 California Specialty Engineering, Flintridge, CA 91012, USA Syracuse Univiersity, Syracuse, USA 4Department of Physics and Astronomy, University of 3California Institute of Technology, Pasadena, USA 4 California, Los Angeles, CA 90095, USA. University of Manitoba, Canada

Data from instruments aboard the MESSENGER Despite geochemical inferences of surface ocean and spacecraft have confirmed that radar bright regions in atmsopheric oxygen accumulation prior to and at the Great permanently shadowed craters, with temperatures less than Oxygenation Event (GOE) at 2.4 Gyr ago, a record of oxygen 100 K, in the north polar region of Mercury are water ice [1- accumulation in the shallow ocean has yet to be demonstrated. 3]. In areas with temperatures up to 350 K, the Mercury Laser Iodine-to-calcium ratios (I/Ca) in carbonates have recently - Altimeter oberserved radar-dark regions which are most likely been revealed as a paleoredox indicator, as iodate (IO ) is 3 an amorphous carbon-rich organic layer with a distribution restricted to oxic waters and is the exclusive iodine species 1 peaking around 160 K, covering and in some cases extending associated with carbonate precipitation . With a similar pE to - beyond near-surface water ice deposits [1,2]. that of O /H O, the presence/absence of IO is a more 2 2 3 Simple organic molecules and water are delivered to sensitive indicator of deoxygenation than other redox- Mercury by cometary impacts. A portion of these molecules dependent elements such as and nitrogen, making could migrate to the polar regions of Mercury and become I/Ca ideal for evaluating in situ redox in the early shallow cold-trapped in permanently shadowed craters [4,5]. The ocean. Analysis of I/Ca in a series of Archean and Proterozoic magnetic field lines of Mercury create a cusp where solar dolomites show that the initial shift in I/Ca began at the GOE wind plasma is transferred to the planet’s surface in the north with a further increase following this at the Lomagundi carbon polar region with a peak proton flux of 1.9 x 108 cm2/s [6]. isotope excursion (LE). A tentative threshold for surface water Ion radation processes organic molecules to species with oxygen accumulation of > 1 µM at the GOE is inferred from greater molecular weights and greater C/H ratios as hydrogen the shift in I/Ca from observations at modern oxygen ions escape. This process can continue until the organics minimum zones2. A second order control on I/Ca ratios is the become amorphous carbonaceous material or even graphite or total iodine reservoir size, which is largely controlled by the other forms of elemental carbon which have low albedos burial and remineralization of organic matter. The LE is similar to those of the dark material obseved in permanently widely accepted to have resulted from an intense relative shadowed craters. Based on estimated proton and electron increase in organic carbon burial rates. The increase in I/Ca at fluxes to the north polar region of Mercury, 3.35 x 1027 the LE, despite likely reduction in the total iodine reservoir molecules/cm2 of polycyclic aromatic hydrocarbons can be size due to organic burial, suggests expanded oxygenation, created from processing methane over the lifetime of the solar potentially into deeper water settings. Increasing I/Ca from a system. Due to the ion radiation and source of organic stratigraphic section of the Mcheka Formation, representing molecules, it is likely that the radar-dark material is highly the later stage of the LE, may reflect increasing total iodine processed carbonaceous organic material. reservoir size, as organic carbon remineralization begins to

outpace burial as carbon isotopes begin to retreat from > 10 ‰ [1] Paige et al (2013) Science 339, 300-303. [2] et to near 6 ‰. More generally, these data highlight the potential al (2013) Science 339, 296-300. [3] Lawrence et al (2013) strength of the I/Ca proxy even in Precambrian samples. Science 339, 292-296. [4] Zhang & Piage (2009) GRL 36,

L16203. [5] Zhang & Paige (2010) GRL 37, LO3203. [6] [1] Lu, Jenkyns & Rickaby (2010), Geology 38, 1107-1110. Mouawad et al (2011) 211, 21-36. [2] Rue, Smith, Cutter & Bruland (1997), Deep-Sea Research 44, 113–134

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Sr isotope stratigraphy of carbonate Experimental incorporation of U into fraction in oil shales xenotime at 900 °C, 500-1000 MPa Y. HARLAVAN* AND O. GOREN utilizing alkali-bearing fluids Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem. DANIEL E. HARLOV AND DIETER RHEDE (*correspondence: [email protected]) GeoForschungsZentrum, Telegrafenberg, D-14473 Potsdam,

Germany ([email protected]) Oil shale is a term used for immature, organic-rich, fine- grained sedimentary rocks from which hydrocarbons can be In this study, specific areas of a natural Th-absent, low U, produced. In Israel, these rocks are composed of four main xenotime [(Y+HREE)PO ] of uniform composition, are components: carbonate, phosphate, organic matter, and 4 experimentally enriched in U + Si utilizing a NaF + H O fluid detritus (mainly Al-Silicates). The studied oil shales sequence 2 plus UO and SiO under both reducing (graphite-CO/CO is dated by their stratigraphic position (Bio-Zone) to Campan- 2 2 2 buffer) and oxidizing (Mt-Hm buffer) conditions. Charge and Maastricht. fluid were sealed in 2 cm long, 3 mm diameter Au and Pt The use of 87Sr/86Sr ratio from marine sediments is in one capsules. In the reduced experiment the Au capsule was of two ways: to determine the Sr isotopic composition of the placed in the piston-cylinder apparatus (CaF assembly; ocean water at deposition time, or to determine the age of the 2 graphite oven; 1000 MPa; 900 °C; 8 days). In the oxidized sediment based upon ocean water 87Sr/86Sr changes with time experiment (500 MPa; 900 °C; 4 days) the Pt capsule was (Sr isotope stratigraphy). packed with Hm + H O into a 4 cm long, 5 mm diameter Pt In the present study we examined the potential of calcite in 2 capsule, which was placed in the gas apparatus. BSE imaging oil shales to reflect the 87Sr/86Sr of the ocean water at time of indicates that the altered areas occur as a series of curvilinear formation. The absence of dolomite in the studied oil shales intergrowths with sharp compositional boundaries that extend sequence suggests that the associated calcite was not from the edge of the xenotime grain into the interior. EPMA significantly altered and therefore should reflect the isotopic indicates that the altered areas from both experiments are composition of Sr in the ocean water at time of formation . 4+ 4+ enriched in U + Si via the coupled substitution U + Si = The carlcite and insoluble residue fractions in oil shales from (Y+HREE)3+ + P5+. WDS element distribution maps indicate different basins in Israel, were separated using sequential that U + Si are concentrated close to the compositional extraction and their Sr isotopic composition was determined. interface between the altered and unaltered xenotime with The numerical Sr ages of the calcit was calculated [1] and corresponding depletion in Y+HREE. Across the altered results show that the numerical stratigraphic age is in good region Y occurs as a series of concentric waves of relative agreement with the assigned bio-stratigraphic age. Moreover, enrichment and depletion with contrasting depletion and the 87Sr/86Sr ratio of the insoluble residue should reflect the enrichment in HREE (see Y element map below). source of detritus transported to these basins and may shed

light on their province. The 87Sr/86Sr ratio of the insoluble

residue varies and has no correlation with the Sr isotopic ratio

of the calcite. This strengthens the observation that the calcite

fraction in oil shales can record the 87Sr/86Sr ratio of the ocean

water. Furthermore, the observed strong correlations between

(1) the 87Sr/86Sr ration and 1/Sr and (2) Sr, Ca and P

concentrations in the insoluble residue, indicate a mixture of

two PO -minerals which are likely to be of biogenic and 4 magmatic origin.

[1] McArthur, Howarth & Bailey, (2001). Journal of Geology 109,

155–169. (LOWESS V5).

Element movement is interpreted as a consequence of fluid- mediated coupled dissolution-reprecipitation in some sort of a chromatographic column effect across the altered area. Fluid- aided incorporation of U into xenotime has implications with respect to its utilization as a metamorphic geochronometer.

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Phase identification of complex Cu- Using isotopic and morphological Fe sulfides using Time-of-Flight evidence to determine biogenicity of Secondary Ion Mass Spectrometry gypsum precipitates in the Frasassi (ToF-SIMS) caves, Italy YOGESH KALEGOWDA1 AND SARAH L HARMER1 KHADOUJA HAROUAKA1*, MATTHEW GONZALES1 , 2 1 1 ANTON EISENHAUER AND MATTHEW FANTLE School of Chemical and Physical Sciences, Flinders University, Bedford Park, Adelaide, South Australia 5042 1Penn State University, University Park 16802, USA ([email protected]) *(correspondence: [email protected]) 2 IFM-GEOMAR, Kiel D-24148, Germany ToF-SIMS is a monolayer-sensitive surface analytical technique that has been extensively used in mineral processing The process of can leave unique to identify the elemental and molecular composition of a fingerprints in the chemical and physical properties of a mineral surface. The combination of mass spectrometry and mineral, specifically in its isotopic composition and imaging makes ToF-SIMS a sensitive and capable technique morphology. In the Frasassi cave system (Italy), gypsum for precisely identifying surface chemistry and its distribution forms at the cave wall-atmosphere interface as a consequence across the surface. Traditionally, ToF-SIMS mass spectra have of limestone corrosion by sulphuric acid, which is produced

been used to provide the surface chemistry of an ore with little by H2S oxidation mediated by microbes (i.e., Acidithiobacillus

specificity to the local surface chemistry of a particular thiooxidans). We sampled gypsum, drip water, and H2S(g)

mineral phase. Some mineral specificity has been achieved by from the Grotto Bella chamber near an active H2S vent, and

imaging particles using a major element of their composition. measured mineral aspect ratios, particle size, mineral and H2S 34 44 However, the identification of mineral phases that contain the ! SCDT, mineral and limestone ' CaSRM915a, and drip water same elements in a mixed multi-metal mineral system like elemental concentrations to find evidence of

chalcopyrite (CuFeS2) and bornite (Cu5FeS4) presents a unique biomineralization. The gypsum occurs in three distinct challenge for ToF-SIMS. The addition of precipitated, morphologies: equant microcrystalline (<50 µm) crystals, wall adsorbed, reacted and contaminant species in the outermost crust, and needles up to 1 cm in length. The crust is molecular layers produce complex mass spectra that are characterized by small needles and aggregates of difficult to interpret using conventional methods. microcrystalline gypsum held together by biofilm. In Grotta

For the effective analysis of such mineral systems, Bella, smaller crystals are generally proximal to the H2S sufficient sensitivity and selectivity are required to detect source, whereas larger needles are found distally. The significant components of the mass spectra. Furthermore the microcrystalline gypsum and needles are fractionated in !34S

determination of surface chemistry, on a particle by particle from the H2S by -12 and -6‰ (2- .1‰) respectively. The basis, requires the selection of a particular mineral phase and '44Ca of the microcrystalline and needle deposits are offset statistical analysis of particles with an estimation of the from the limestone wall by -0.04 and -0.84‰ (2-.0.23‰) variability of the value. The complex mass spectral data sets respectively. A biogenic origin of the microcrystalline gypsum were analyzed using an adaption of principle component may be deduced from the unusually low aspect ratios and 34 analysis – artificial neural networks (PCA-ANN). The analysis highly negative ! S relative to the H2S. The microcrystalline of ToF-SIMS data, has resulted in the successful classification morphology may have arisen by crystal nucleation on of bornite, chalcopyrite, chalcocite and pyrite at different individual cells embedded in the biofilm. The negative '44Ca flotation stages. A method for phase identification of particles of the needles may also suggest biogenicity, as the bacteria using ToF-SIMS has been used to track the surface chemistry tend to colonize the larger gypsum needles more than the of an individual particle throughout complex processing smaller morphologies. procedures[1].

[1] Yogesh Kalegowda and Sarah L Harmer (2012) Anal. Chem., 2012, 84 (6), 2754–2760.

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Enhancing CO2 sequestration in Magnetic nanostructures in Mg-rich mine tailings meteorites: A window on the early A. L. HARRISON1*, I. M. POWER1, S.A. WILSON2, solar system 1 1 G.M. DIPPLE AND K. U. MAYER 1 1 1 R.J. HARRISON *, J. BRYSON , N.S. CHURCH , 1The University of British Columbia, Vancouver, V6T 1Z4, T. KASAMA2, J. HERRERO ALBILLOS 3 Canada (*correspondence: [email protected]; 1 Department of Earth Sciences, Univ. Cambridge [email protected], [email protected], (*correspondence: [email protected]) [email protected]) 2 Center for Electron Nanoscopy, Technical University 2Monash University, Clayton, VIC 3800, Australia Denmark, Copenhagen ([email protected]) ([email protected]) 3ICMA, University of Zaragoza ([email protected])

Mineralization of atmospheric CO within carbonate minerals 2 Paleomagnetic signals recorded by meteorites are a potent occurs passively in Mg-rich mine tailings via weathering of Mg- source of information about processes occuring during the bearing primary minerals [1]. Passive carbon mineralization has been early solar system. This talk sets out the challenges that we documented at the Mount Keith mine (MKM) in Western face when attempting to extract meaningful magnetic Australia [1]. Field data and reactive transport modeling indicate that information from such ancient and complex materials. To passive mineralization occurs primarily via carbonation of brucite overcome these challenges we must search for the most ideal [Mg(OH) ], and is limited by the supply of CO . MKM produces ~0.1- 2 2 carriers of magnetic remanence (i.e. those displaying the 0.3 Mt brucite/yr in tailings; complete carbonation of this brucite highest magnetic stability and the highest resistance to would sequester up to 60% of mine emissions [2]. Thus, modification thermochemical alteration and shock demagnetistion) – a of tailings management practices to enhance brucite carbonation rates search that us away from the conventional bulk could provide a significant offset of emissions. paleomagnetic methods that have served us so well over the Two strategies are proposed to enhance CO sequestration. First, 2 past 60 years, and towards the development of spatially passive carbonation could be accelerated by maximizing the exposure resolved measurments that will take to the of brucite to atmospheric CO . Mineral abundance profiles from 2 micrometre scale and beyond. tailings of different ages at MKM and reactive transport modeling Using a combination of state-of-the-art electron and X-ray with MIN3P [1,3] were used to calculate the rate of brucite imaging methods, we show that Fe-Ni metal carries a carbonation with depth below the tailings surface. It is estimated that chemical transformation remanent magnetisation (CTRM) passive sequestration would be maximized if brucite remained at the encoded within a spinodal decomposition nanostructure that surface for twice the current duration (i.e., burial rates decreased). formed continuously during slow cooling. This nanostructure A second strategy is to actively supply CO -rich gas streams into 2 is comprised of nanoscale islands of a magnetically hard phase tailings [2]. Column experiments containing brucite were conducted to (chemically ordered FeNi) coherently intergrown with a assess carbonation efficiency with injection of CO -rich gas into 2 hitherto unobserved soft magnetic phase (chemically ordered partially saturated systems akin to mine tailings. The effect of brucite Fe Ni), that developed progressively along pre-existing Ni grain size, water content, and reaction path length were assessed. 3 concentration gradients. Dramatic variations in magnetic Experimental and modeling results indicated that brucite grain size behaviour are observed across a lateral traverse of the spinodal should be minimized to prevent the development of a passivating region, which can be related to variations in the underying surface layer. Moreover, tailings water content should be maintained nanostructure that developed during progressive cooling. above residual saturation to optimize carbonation. The experimental cooling models predict that spinodal nanostructures rates suggest that the CO sequestration potential in tailings would 2 within chondritic meteorites formed during a time when the become limited by the brucite content rather than the reaction rate if proposed asteroid core dynamo was active. We argue that CO -rich gas were supplied. These results will guide implementation 2 microstructures forming in Fe-Ni metal from chondritic of accelerated CO sequestration strategies at mine sites. 2 meteorites have the potential to reveal a time-resolved record

of asteroid dynamo activity during the first 100-200 Ma of the [1] Bea et al (2012) Vadose Zone J. 11. [2] Harrison et al (2013) asteroid’s history – a record that would be the nanometre scale Environ. Sci. Technol. 47, 126-134. [3] Molins & Mayer (2007) Water equivalent of the kilometre scale magnetic anomalies recorded Resour. Res. 43, W05435. by oceanic crust on Earth.

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Reconstructing Societal Dynamics of Can mineral inclusions in the Ancient Maya: metamorphic rutile help to constrain Insights from Nd Isotopes P-T conditions of formation? E. HARRISON-BUCK1, J. G. BRYCE2, J. BLICHERT-TOFT3 EMMA HART1, CRAIG STOREY1 AND EMILIE BRUAND1 1UNH Dept. of Anthropology, Durham NH, USA, e.harrison- 1School of Earth and Environmental Sciences, University of [email protected] Portsmouth, PO1 3QL, UK. (*correspondence: 2UNH Dept. of Earth Sciences, Durham, NH 03824, USA. [email protected]) 3Ecole Normale Supérieure de Lyon, Lyon, France. Peak metamorphic temperatures of rutile can already be Ethnoarchaeological studies of cultures, such as the Maya, determined using the Zr-in-rutile geothermometer [1], suggest that technical choices, such as the selection of clay however little work has been carried out to develop rutile as a and temper for pottery production, are socially informed geobarometer. actions that are among the strongest indicators of a group’s We therefore aim to investigate the use of rutile as a single social identity. Yet, archaeologists typically carry out stylistic grain geothermobarometer by analysing mineral inclusions analyses of artifacts (e.g. examining the painted designs on found within rutile. This work will be used in conjunction with pottery), and fail to analyze the technological aspects of the average P-T calculations using THERMOCALC 3.3, material culture. Geochemical studies offer a valuable method providing a novel way of constraining conditions of rutile for examining the fabric of ceramic production that can reveal formation. changes in local pottery manufacture and exchange and can also point to significant shifts in long-distance trading activity Rutile grains from a number of localities been over time. Current methods for chemical sourcing use characterised using EPMA. Raman spectroscopy will be used statistical analyses to group ceramics based on elemental to analyse quartz inclusions in UHP rocks, e.g. Dora Maira, to compositions derived from Instrumental Neutron Activation determine if coesite is present. Analysis and Inductively Coupled Plasma Mass Spectrometry. Both techniques yield data that can be analyzed statistically to determine differences within and between groups in order to generally distinguish the proportion of locally made pottery from those that appear to be imports. This approach is problematic in terms of its sample preparation and study and limiting in terms of its degree of accuracy. Strontium isotopes have been commonly used in many locations in Belize watersheds, but their interpretations for sourcing local clay deposits are complicated by overprinting by carbonate-based temper. Here, we present new Nd isotope data that appear to be especially useful for isolating imported pottery and determining shared provenance for specific types of local ceramics from ancient Maya sites in the eastern Belize Figure 1: Back-scattered image of a rutile grain with a pyrope

Watershed. The Maya pottery shows a range of up to 6 "Nd mineral inclusion from the Dora Maira Massif. units, enabling the detection of specific production locales and shifting trade orientation consistent with changes in Preliminary EPMA data shows that inclusions in rutile socioeconomic organization, likely resulting from new social comprise minerals useful for determining groups entering the eastern Belize Watershed during different geothermobarometric conditions, e.g. glaucophane, omphacite periods of Maya history. The Nd isotopic data, integrated and phengite. Pyrope and almandine garnet inclusions have with the stylistic analyses of the artifacts, clearly reveal the also been discovered in UHP rocks from the Western Alps complexity of ancient patterns of mobility and trade, (fig. 1). particularly at the time of the collapse at the end of the Classic period, and afford new insights into the societal dynamics of [1] Zack et al (2004) Sedimentary Geology, 171, 37-58. the ancient Maya.

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Source heterogeneities deduced from Melt injections and metasomatism in spatial and temporal geochemical the continental mantle lithosphere patterns in continental basalts beneath southern Africa W.K. HART1*AND M.E. BRUESEKE2 BEN HARTE 1Dept. of Geology and Env. Earth Sci., Miami Univ., Oxford, Centre for Science at Extreme Conditions, School of OH 45056, USA Geosciences, University of Edinburgh, King’s Buildings, (*correspondence: [email protected]) Edinburgh EH9 3JW, Scotland, UK. ([email protected]) 2Dept. of Geology, Kansas State Univ., Manhattan, KS 66506, USA ([email protected]) A wide spectrum of melt-related phenomena have been identified in mantle xenoliths and xenocrysts from southern Deciphering the mantle source(s) of basaltic magmas African xenoliths. At one end of this spectrum are the erupted in continental settings is challenging due to the megacrysts of the Cr-poor megacryst suite, which appear to be potential geochemical and isotopic overprints imparted by direct crystallisation products from a melt body. At the other continental lithosphere. In addition, both lithospheric and sub- end of the spectrum are peridotite xenoliths with no lithospheric mantle reservoirs are variously implicated in megascopic signs of melt injection, but showing trace element continental basalt generation. As a result, intracontinental evidence of metasomatism by melt percolation. In between locations with extensive exposures of time-transgressive basalt these extremes are xenoliths showing apparently intrusive flows can be extremely important for unraveling the relative sheets and injected veins, as seen in the MARID suite of the contributions of these reservoirs. Kimberley area (South Africa) and the IRPS suite of Matsoku In this context, we describe the spatial, temporal, (Lesotho). Evidence of melt intrusion, disruption and chemical, and isotopic characteristics of basaltic volcanism on metasomatism is also shown by the polymict peridotite suite. the Owyhee Plateau, USA. The Owyhee Plateau (OP) lies at Close major-minor element compositional links exist the intersection of the Snake River Plain-Yellowstone and between megacryst suite minerals, some Fe-Ti-rich high- Oregon High Lava Plains magmatic trends; a region affected temperature deformed xenoliths, and the metasomatised by the initial upwelling of the Yellowstone hotspot ~17 peridotite host rocks to intrusive IRPS-rich sheets. The major- million years ago. It is the only location in the Pacific minor element compositions of minerals in the Matsoku IRPS Northwest directly affected by Yellowstone-hotspot related suite show close similarities to the matrix minerals of polymict volcanism that also contains a continuous record of basaltic peridotites. Estimates of the trace element compositions of volcanism over the past ~17 Ma [1]. OP basalt compositions melts percolating through Jagersfontein peridotite xenoliths include primitive to fractionated tholeiitic and mildly alkaline evolve from compositions close to those estimated for varieties with incompatible trace element and Sr, Nd, and Pb megacryst magmas to those estimated for kimberlites. It isotope ratios that are decoupled from the bulk chemistries, appears that many phenomena show evidence of a lineage and that are time dependent [1,2]. going back to similar Cr-poor megacryst magmas interacting The OP basalt suite reveals how mantle sources of over thicknesses of ca 100km with a diverse mantle intracontinental mafic magmas can vary as a function of time lithosphere. and lithospheric structure in a geographically restricted location. In this region, the heterogeneous mantle sources result from location along a distinct continental lithosphere transition, a major episode of sublithospheric mantle upwelling, and prolonged regional subduction leading to geochemical modifications of the lithosphere-asthenosphere boundary region that influence the nature of subsequent magmatism. Recent geophysical and geodynamic modeling results support these geochemical-based interpretations [3].

[1] Shoemaker & Hart (2002) Idaho Geol. Surv. Bull. 30, 313- 328. [2] Hart (1985) Geochim. Cosmochim. Acta 49, 131-144. [3] Long et al (2012) Geochem. Geophys. Geosys. 13, doi: 10.1029/2012GC004189.

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Subducted carbon in stagnant slabs: Colloidal metals in stalagmites: Evidence from ‘deep’ diamonds Potential for palaeohydrology BEN HARTE ADAM HARTLAND1, IAN. J. FAIRCHILD2, WOLFGANG MULLER3 AND DAVID DOMINGUEZ-VILLAR4 Centre for Science at Extreme Conditions, School of Geosciences, University of Edinburgh, King’s Buildings, 1 University of Waikato, Hamilton, New Zealand. Edinburgh EH9 3JW, Scotland, UK. [email protected] 2 University of Birmingham, Birmingham, B15 2TT, UK. Evidence has been accumulating of diamonds containing 3 Royal Holloway University of London, Egham, Surrey, mineral inclusions of unusually deep origin (250 to 800 km). TW20 0EX, UK. In the case of ‘deep’ diamonds with silicate inclusions 4 Centro Nacional de Investigación sobre la Evolución 13 indicating basic rock protoliths, the diamonds have ' C Humana, Burgos, Espana. values extending as low as -24 ‰ and suggestive of organic carbon. Other evidence of an initial ocean floor protoliths is There is increasing recognition of the role of organic shown by Eu anomalies in some inclusions. ‘Deep’ diamonds colloids and dissolved natural organic matter (NOM) in trace with inclusions indicating ultrabasic protoliths, commonly metal trasport in karst systems. In particular, we now know appear to have formed at depths of 500 to 750 km and have 13 that colloid-facilitated transport of trace metals responds in a ‘normal’ mantle ' C values of -4 to -6 ‰. However, these diamonds are also believed to be derived from subducted coherent way to surface infiltration patterns [1] and that this oceanic lithosphere in the form of hydrous meta-peridotites may be encoded meaningfully in speleothems [2]. that have undergone dehydration reactions near the This study combines measurements of aqueous colloid- Upper/Lower Mantle boundary [1]. Time constraints from metal species from dripwaters, with trace metal and organic diamonds and inclusions erupted in the Juina area, Brazil, carbon data from a conjugate hyperalkaline speleothem. Thus, suggest the subducted lithosphere to be of early Mesozoic age, for the first time the capture of the inorganic and organic with diamond formation occurring as the oceanic lithosphere components of dripwaters by speleothems is studied in a descended and formed a subducted stagnant slab near the quantitative way. Upper/Lower Mantle boundary (see figure). The diamonds Our results indicate that the partitioning of NOM- were erupted back to the surface by kimberlites during the transported metals into speleothems is proportional to the Cretaceous. strength of the aqueous NOM-metal complex. In practice, this means that some metals (e.g. Cu, Zn) more closely reflect hydrological changes (readily dissociate to bind with calcite), while other elements (e.g. Co, Br) more closely encode information on NOM capture, i.e. they less readily dissociate from aqueous complexes. We also provide evidence for kinetic effects on NOM incorporation in the speleothem and show that the ratio of certain trace metals (e.g. Cu/Ni) in stalagmites may also reflect compositional fluctuations in the NOM, consistent with high and low molecular weight trends also seen in dripwaters.

[1] Hartland et al (2012) Chem. Geol. 304-305, 68-82. [2] Jo, K.N. et al (2010) EPSL 295, 441–450. [1] Harte (2010), Mineralogical Magazine 74, 189-215.

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Arsenic in surface sediments of a Sub-arc "11B: The introduction of harbor sludge dumping site and a boron isotope heterogeneity into the natural deposition site in the convecting mantle Helgoland Mud Area, North Sea JASON HARVEY 1*, CARLOS J. GARRIDO2, SAMUELE 3 4,5 1 2 AGOSTINI , JOSÉ-ALBERTO PADRÓN-NAVARTA , JAN F. HARTMANN , SABINE KASTEN , THOMAS 2,4 1 1 VICENTE LÓPEZ SÁNCHEZ-VIZCAÍNO , IVAN P. KRENGEL AND MARGOT ISENBECK-SCHRÖTER * SAVOV1, CLAUDIO MARCHESI 2 1 Inst. of Earth Sciences, Heidelberg Univ., Im Neuenheimer 1 School of Earth & Environment, University of Leeds, UK Feld 236, 69120 Heidelberg, Germany (*corr.: [email protected] (*presenting author) [email protected]) 2 Instituto Andaluz de Ciencias de la Tierra (IACT), CSIC-UGR, 2 Alfred Wegener Institute for Polar and Marine Research, Am Armilla, Granada, Spain Handelshafen 12, 27570 Bremerhaven, Germany 3 Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR, Pisa,

Italy In order to analyse differences in concentration, speciation 4 Research School of Earth Sciences, The Australian National and total mobility of arsenic two different locations were University, Canberra 0200, ACT, Australia studied near the Helgoland Mud Area, North Sea. 5 Géosciences, Montpellier, CNRS (France) The first location is characterised by natural

sedimentation, the second by deposited sediments dredged The Cerro del Almirez Massif in Spain preserves field from the port of Hamburg. Porewater as well as sediment evidence for the prograde transition from antigorite- profiles were analysed with respect to arsenic compounds (As (ant-serp) to chlorite- (chl-harz) in a (III) and total As) and major redox species as total and paleo-subducting slab. This study investigates B isotope reactive manganese and iron. The sediment samples were fractionation in the sub-arc region, where fluid loss handled under inert atmosphere before and during extraction accompanies prograde metamorphism under well constrained by water, phosphate, hydrochloric acid and aqua regia. Total pressure and temperature conditions (650 °C, 1.7 GPa [1]). element contents in porewater and leachable extracts of Boron isotopes are strongly fractionated during the sediment fractions were analysed. dehydration of ant-serp, with a sharp decrease of '11B across The results show a strong redox coupling of arsenic with the ant-serp to chl-harz isograd. Ant-serp has a '11B of +22.6 manganese and iron. Oxidized arsenic seems to adsorb to ‰ (± 1.6), similar to the heaviest '11B in manganese- and iron-oxyhydroxides in surface sediments. In recovered from the forearc region of the Mariana subduction contrast to the solid samples, the pore water data shows a zone [2, 3], whereas prograde lithologies preserve '11B of release of As (III) into porewater when manganese- and iron- +3.3 ‰ (± 0.3) to '11B of -3.5 ‰ (± 0.3). oxyhydroxides are reduced in the upper part of the cores. Also Although the rapid drop in '11B demonstrates that massive B a remobilisation of As (V) occurs. Downward diffusing isotope fractionation occurs at sub-arc depths, the absolute amount of arsenic can be fixed by carbonate below the zone of boron lost during dehydration is negligible compared to B lost from manganese and iron reduction. In the anoxic parts of the the downgoing slab in the forearc at the onset of subduction (c. sediments As (III) and As (V) are released and could be fixed 85%)[4]. Lithologies on either side of the isograd contain 7-12 ppm B at authigenic iron sulphide or arsenic sulphides formation. A with only minimal loss of B accompanying dehydration. This means sulfidic precipitation of arsenic in iron-dominated systems is that any B that survives ant-serp dehydration has the potential to be limited by the occurrence of HS-. transported past the sub-arc region and into the deep, convecting Total solid-phase contents in leachable extracts of mantle. Prograde chlorite is not the major host of this boron - it is sediment fractions of the natural area show significant higher mostly contained in prograde olivine-hosted inclusions[5], unlikely to arsenic concentrations than the core of the anthropogenic suffer any subsequent dehydration reactions. The delivery of B with dumping area. This is due to the higher fines content of the '11B of +3.3 ‰ to '11B of -3.5 ‰ into the asthenosphere therefore Helgoland mud area. provides a possible source for OIB (e.g.[6]) whose '11B is Higher total porewater contents of iron and arsenic in the significantly lighter than primitive mantle. core of the anthropogenic dumping area thus due to higher turnover rates of organic matter by iron reduction. Higher [1] Padrón-Navarta et al (2011) J. Petrol. 52, 2047-2078. concentrations of arsenic may be due to a higher availability [2] Savov et al (2007), J. Geophys. Res, of iron in the dumped sediments. doi:10.1029/2006JB004749 [3] Pabst et al (2012) Lithos 133, 162-179. [4] Kodolanyi and Pettke (2011) Chem. Geol. 284, 351-362. [5] Scambelluri et al (2004) Earth Planet. Sci. Lett. 222, 217-234. [6] Turner et al (2007) Nature 447, 702-705.

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Copper mineralization prevented by Relationship between modern arc-root delamination during Alpine- speleothem formation and surface Himalayan collision in Iran weather in an Asian tropical cave MICHAEL HASCHKE1, JAMSHID AHMADIAN2, FATEMEH W. HASEGAWA1*, Y. WATANABE1, H. MATSUOKA1, SARJOUGHIAN3, BEHNAM SHAFIEI4 S. OHSAWA2, B. BRAHMANTYO3, K. A. MARYUNANI3 1 1 AND T. TAGAMI UIT Dresden, Am Windkanal 21, 01109 Dresden, Germany 2Dept. of Geology, Payame Noor University, Tehran, Iran 1Earth and , Kyoto univ., Kyoto, Japan 3 Dept. of Earth Sciences, Univ. of Kurdistan, Sanandaj, Iran (*correspondence: [email protected]) 4Dept. of Geology, Golestan Univ., Gorgan, Iran 2Institute of Geothermal Science, Kyoto univ., Beppu, Japan 3Earth Sciences and Mineral Technology, Institut Teknologi The formation of Cu-Au-Mo porphyry deposits in Iran is Bandung, Bandung, Indonesia linked to continental collision, yet there are no clear temporal relations between geochemical signatures of Miocene For precise climate prediction, it is necessary to (collisional) and Eocene (pre-collisional) intrusive arc rocks, reconstruct high time and space resolution paleo-climate and the presence/lack of ore mineralization. We compare (especially past 2000 years) from paleo-climate proxies and geochemical scenarios from five different segments along the assimilate the result to climate model. Tropical Asia, including Urumieh-Dokhtar arc and propose a geodynamic model to Indonesia, is well affected by El Niño Southern Oscillation explain this discrepancy. For instance, in the Natanz arc (ENSO). The ENSO does not only directly affect on segment in central Iran, contrasting geochemical signatures of precipitation in tropical Asia, but also indirectly on middle and ore hosting Eocene and some barren undeformed high latitude climate through teleconnection [1]. In Indonesia, Miocene diorites to granites temporally overlap with the Watanabe et al [2] suggested inverse-correlation between '18O Alpine-Himalayan collision. These changes provide key and '13C in speleothems and instrumental precipitation. implications on the existence and lack of Cu mineralization However, relationship between modern speleothem formation during collisional magmatism. High Sr and low Y (and Yb) and surface weather is not revealed clearly. contents of Eocene arc rocks in the Natanz arc segment reflect Thus cave monitoring program was initiated from 2011 in thickened, Andean-type orogenic arccrust (~45 km), whereas Petruk Cave (Central Java, Indonesia) in order to study the barren Miocene Natanz arc rocks (21-19 Ma) indicate thin arc recording mechanism of precipitation variation into the '18O crust similar to collisional volcanism in Anatolia. and '13C fluctuation in speleothems.

Geochemical modeling indicates a change in the mineralogy Air CO2 concentration in Petruk Cave is fluctuated daily of the melt residual, from precollisional Eocene basaltic and seasonally until over 100 m deep site from the entrance.

garnet-bearing (5-30%) amphibolite to syn- or postcollisional It is revealed that cave air CO2 concentration may be a Miocene metasomatized mantle peridotite, which can be significant factor that controls stable isotope value in explained by collision-induced delamination of the arc speleothems, because temperature, humidity and drip rate in lithospheric root. Subsequent recharge of hot asthenosphere Petruk cave are nearly stable. and melting of metasomatized mantle peridotite and lack of A scenario of precipitation recording is as follows: (1) interaction with a garnet-bearing arc crustal keel explain the surface rainfall cools outside air temperature; (2) cave airflow low Sr and high Y (and Yb) contents, the relatively enriched direction is inversed; (3) outside fresh air flows into the cave

initial Sr isotope ratios of postcollisional Miocene Natanz and air CO2 concentration is dropped; (4) pCO2 difference rocks, and the lack of copper mineralization in postcollisional between cave air and dripwater becomes higher and calcite Miocene Natanz arc rocks. Arc-root delamination removes the precipitation is promoted; (5) '18O and '13C in speleothems copper- and sulfurenriched metasomatized lithospheric arc are decreased. root and hydrous cumulate reservoir required to form copper ore deposits. Lack of the dense melt residues also provides an [1] Hastenrath (1991) Climate dynamics of the tropics. [2] alternative explanation for the elevated, thin crustal Iranian Watanabe et al (2010) Palaeogeography, Palaeoclimatology, back-arc plateau (38 km) as a result of uplift by isostatic Palaeoecology 293, 90–97. rebound rather than uplift by anomalous shortening. Miocene arc-root delamination implies a minimum age of >21 Ma for the Alpine-Himalayan collision in central Iran.

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Origin of laminations in BIF Net community and gross primary deciphered from N and Fe isotopes production in the Southern K. HASHIZUME1*, D.L. PINTI2, B. ORBERGER3, California Bight based on carbon C. CLOQUET4, M. JAYANANDA5 AND H. SOYAMA1 export, dissolved O2/Ar and triple 1Dept. of Earth & Space Sci., Osaka Univ., Toyonaka 560- oxygen isotopes: Exploration of how 0043, Japan (*[email protected]) 2GEOTOP, H2X 3Y7, Montréal, Qc, Canada the magnitude and timing of 3Groupe ERAMET, 75755 Paris, France upwelling events may influence 4CRPG-CNRS, BP 20, 54501 Nancy, France 5Dept. of Geology, Univ. of Delhi, Delhi 110 007, India export efficiency W.Z. HASKELL II 1, M.G. PROKOPENKO 1, Elucidation of the formation process of banded iron D.E. HAMMOND 1, R.H.R. STANLEY 2, W.M. BERELSON1 formations (BIF) is the major purpose of this study. Not only 1 the iron oxidation process itself, but the alternation between Dept. of Earth Sciences, University of Southern California, the quartz- and iron-rich layers may provide important clues 3651 Trousdale Pkwy, Los Angeles, CA, 90089, USA on the emergence of the oxygen in the early atmosphere. [email protected] 2 A >2.72 Ga old BIF from Dharwar Craton, southern India, Dept. of Marine Chemistry, Woods Hole Oceanographic was studied. Compositions of N, Fe and Ar isotopes, major Institution, 266 Woods Hole Rd., Woods Hole, MA, and trace elements including REEs were analyzed among 10 02543, USA qz- or Fe-oxide-rich bands from the sample. REE and trace element compositions of the samples indicate a minimal Biologically driven deviation of dissolved O2 from influence from the continental crust, allowing us to propose a equilibrium concentrations, determined from O2/Ar ratios, has relatively simplified view of the water column from which long been used as a tracer of net community production (NCP) constituents of the BIF sample precipitated. Qz- and Fe-rich in the oceans, as O2 is a counterpart of carbon in layers showed contrasting compositions of N, Fe and Ar photosynthesis and respiration. Over the last decade, a isotopes and of REEs. A positive correlation between !15N and technique using the triple oxygen isotope composition (TOI) !56Fe values, which range from +2 to +12‰ and +0.9 to of dissolved O2 has been applied in many regions of the ocean +2.2‰, respectively, is the major finding of this study. Qz- to estimate gross biological oxygen production (GOP) in the rich layers exhibit higher Eu anomalies correlated with surface mixed layer. The TOI approach rests on using the 40Ar/36Ar ratios. This trend is explained by the contribution of deviation from mass dependent fractionation of the three 16 17 18 a constant amount among all bands of a hydrothermal oxygen isotopes ( O, O, O) in the mixed layer to distinguish component, added to Y-rich REE and 36Ar-rich Ar between photosynthetic in situ produced O2 and atmospheric components, which possibly represent Archean oceanic and O2 supplied through gas exchange. This “dual-tracer” atmospheric air compositions, respectively, carried by Fe- approach of simultaneous measurements of Net Community bearing minerals. The lower !56Fe values observed among the and Gross Production provides estimates of NCP/GOP ratios, Fe-rich bands could be explained either by anoxygenic which reflect efficiency of carbon export. However, applications of this in-situ technique have been limited in photosynthetic oxidation or O2-mediated abiotic oxidation from an oceanic ferrous iron with a mantle origin. We explain productive coastal upwelling zones because the mixed layer the higher !56Fe values among the qz-rich bands by O2 mass balance is altered by upward advection of water from dissimilatory iron reduction (DIR) by which lighter iron the oxygen deficient zone, which has both O2 concentration isotopes are consumed faster. The qz-rich bands are N-rich, in and TOI composition out of equilibrium with the atmosphere. concentrations and C/N ratios, and 15N-rich, in the isotope The Upwelling Regime In-situ Ecosystem Efficiency ratio. We propose that formation of the qz-rich bands may (Up.R.I.S.E.E.) time-series study is an ongoing effort to correspond to periods when the photosynthetic biological expand the application of the O2-based dual-tracer approach to productivity at the surface of the ocean was active. The DIR the upwelling regimes. In this study, O2/Ar and TOI could have been enhanced during this period by supply of measurements through the upper thermocline are combined abundant organic matter to the iron particles. The biological with estimates of upwelling rates, constrained by a mass 7 activity at the ocean surface could be the switch producing the balance of Be in the surface mixed layer and upwelling laminations in BIFs. indices from wind stress curl. Accounting for the contribution of the deep water O2 signal to the mixed layer O2 and TOI inventory, we test whether the timing and/or magnitude of upwelling events affect an ecosystem's efficiency in exporting organic carbon from the surface ocean in this highly productive setting. Sediment trap deployments and budgets of DIC, DOC, and 234Th are used to further constrain export estimates, and compared to NCP. Preliminary results from the first six months of a two-year study will be presented.

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Metals zone distribution in old ore Late Neoproterozoic Nuqara Dokhan deposits Egypt: A pathfinder for site Volcanics, Central Eastern Desert, of chief metal accumulation Egypt: Geochemistery and MAHMOUD M. HASSAAN 1 petrogenesis 1 [email protected]. Faculty of Sciences, AlAzhar ASRAN.M.H.HASSAN1 ,NATFLOS.THEO 2, AMRON.T 3, University-Egypt. THARWAT.SALEM 4, EL TAKY.M 5

1 Sohage Univ. Egypt.([email protected]) Geochemical zoning, is a reliable exploration criterion for 2 Vienna Univ.Austria ([email protected]) revealing site of accumulation of chief ore metal . Studies 3 South Valley Univ. Egypt ([email protected]) established the clark of concentration CC and zoning 4 South Valley Univ.Egypt ([email protected]) coefficient to investigate the old exploited deposits of gold, 5 South Valley Univ.Egypt ([email protected]) -copper, molybdenum–silver hosted by the Pan-African

ophiolitic, island arc and cordilleran-extension rocks of the The Neoproterozoic Nuqara Dokhan volcanics are one of Nubian shield. These studies considered the general zoning the northernmost outcrops of the Arabian- Nubian Shield . The sequence. Be, Ni, Co, B, Sn, U, Mo, W, As, Bi, Cu(1), Zn, Pb, origin and tectonic setting of these rocks is highly debated Sn(2), Au, Ag, B, As(2), Cu, Sb, Hg, Te, I. The zoning sequence .Debate concerns the tectonic setting they formed as a result of of Sukkari mineralization upward is Au, Sn, Mo, Zn, As, Ni, subduction (El Gabby et al, 1990) or crustal Pb, Ba favoring gold accumulation site deeper than ~ 400 m extension(Stern,1994).Nuqara dokhan volcanics comprises .In Abu Marwat mine the zoning sequences favored increase two main rock suites: (a) an intermediate volcanic suite, of gold northward as follow :Upper zone northern part Ag, Zn consisting of basaltic andesite, andesite and their associated , Mo, Pb, Ba, Au, sn, Cu, Au and lower zone northern part Sn, pyroclastics rocks; and (b) a felsic volcanic suite composed of Ni. Pb, Ba, Au, Zn, Cu, Mo, Ag. The recommended site of dacite, rhyolite and ignimbrites .The two suites display well- gold accumulation is meta-volcanic rocks and quartz veins defined major and trace element trends and continuum in bordering Wadi Abu Marwat from north and their extension composition with wide ranges in SiO2 (52-75.73%), CaO under the Wadi alluvial. The study of Gattar molybdenite- (9.19-0.22%), MgO (5.29-0.05%), Sr (1367-7.4ppm), Zr silver occurrence recorded gold. The vertical zoning sequence (688.5-172.7ppm), Cr (207-0.4 ppm), and Ni (86-0.2ppm).The from altitude 10 m to 953 m . is Au, Cu Pb, (Co, Ni) , Ag, Zn, Nuqara Dokhan volcanics are characterized by strong Sb, (Sn-W), Cr, Mo enhanced 2 mineralization phases and enrichment in LILE relative to HFSE and affiliated to the calc- gold accumulation at deeper levels . In Um Zuriq alkaline subduction – related magmatism .Modeling results mineralization at Wadi kid in Sinai , the data of a drill hole display that the evolution of these rocks was governed penetrated repeated sheared and altered chlorite schist and byfractional crystallization of plagioclase, amphiboles, garnet biotitic andalusite schist forming two limbs of a pyroxene, magnetite and apatite in the intermediate varieties recumbent fold placed basal mineralization zone at south and plagioclase ,amphibole, magnetite ,apatite and zircon in western side above the top of the zone at north eastern part. the felsic varieties. The obtained mineral chemistry of these The recorded sequence Cu(Zn, Pb), Au, Ag upward in the volcanics reveals: (a) Plagioclase range in composition from basal limb is normal and another inverted one for the upper An59 to An55 in basaltic andesite and from An49 to An27 in limb. The mineralization is syngeneic to the schist. The arc- andesite. (b) Alkali feldspars have sanidine composition. (c) like island arc meta-volcanic rocks hosting seven As, Pb, Zn, Clinopyroxenes have composition .The low Al2O3 Cu sulfides litho- structurally controlled forming a belt. In El contents (2.055-5.588 wt %) indicate that clinopyroxene Atshan mine variable high CC values of only Cu and Zn in all crystallized at low – pressure. (d) Amphiboles have ferro rock units favored that the volcanic magma was bearing Cu- hornblende to ferro barrosite composition. Zn. The recorded high Pb and As contents in the talc

carbonate and serpentinite enhanced its relation to dynamo- [1] El Gaby et al (1990) A.A.Balkema,Rotterdam,p.175- 184. thermal activity during thrusting. The vertical zonal sequence [2] Stern RJ (1994) Ann Rev Earth planet sci 22:319 is Fe, Cu , Zn (Pb-As) upward . These features were recorded at the Derhib mine. Similar deposit was recorded in Wadi Allaqi.

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Specific ion effects on the wettability The biogeochemical record: of sandstone particle A new perspective on nitrate T. HASSENKAM, J. MATHIESSEN, M.P. ANDERSSON AND MEREDITH G. HASTINGS1, DOROTHY FIBIGER2, S.L.S. STIPP NATHAN CHELMAN1,3 AND JOSEPH R. MCCONNELL3 Nano-Science Center, Dept. of Chemistry, University of 1Brown University, Department of Geological Sciences and Copenhagen, Denmark ([email protected]) Environmental Change Initiaitve, 324 Brook Street Box 1846, Providence, RI USA, Specific ion effects control most reactions in nature. [email protected] Adhesion, between organic molecules and mineral surfaces in 2Brown University, Department of Chemistry, Providence, RI aqueous solution, depends not only on the behaviour of the USA molecule and substrate but also on the specific set of dissolved 3Desert Research Institute, Division of Hydrologic Science, ions. The complex behaviour between ions, water and organic Reno, NV USA molecules is reflected in various versions of what is known as the Hofmeister series where ion activity depends on size, A major motivation in studying ice core nitrate is to charge and electron configuration. There is a wealth of reconstruct the atmospheric loading of its precursor, nitrogen

experimental data on how organic molecules interact with oxides (NOx). NOx concentrations in the atmosphere play a sandstone, from oil industry work and from environmental significant role in determining tropospheric chemical

studies of soil, sediments and aquifers but the picture of composition and oxidizing capacity. Today, NOx emissions molecular scale interactions is not clear. are primarily the result of fossil fuel burning, with important By using force spectroscopy and chemical mapping with contributions from biomass burning, lightning and biogenic AFM (atomic force microscopy) we can observe contact processes in soils. The result of these emissions is deposition behaviour with a variety of molecules on real sand grains, of nitric acid (i.e., nitrate), a component of acidic precipitation while solution composition is changed. By using tips and a bioavailable nutrient. Recent studies utilizing the functionalised to behave as pure alkane (CH3), we have isotopic composition of nitrate in ice cores offer the possibility probed sand grains, and examined adhesion in NaCl solutions, to trace the sources and chemical processes that contribute to with ionic strength close to that of seawater. Changing nitrate deposition over time. composition of the solution by adding small amounts (12 mM) Studies of the isotopic composition of nitrate in surface of specific divalent ions (Ca2+, Mg2+), corresponding to snow and snowpits at Summit, Greenland reveal an about 2% relative to the number of Na+ ions, caused a atmospheric nitrate signal that is well preserved in recent dramatic adhesion increase between the alkane tips and the snow. A seasonally resolved ice core record of the isotopic surface - by as much as 50%. Increased adhesion is a clear composition of nitrate, together with highly resolved (> 22 response to higher divalent ion density at the surface. samples yr-1) elemental and chemical tracers are used to

However, in 0.5 M NaCl, the electrical double layer collapses investigate changes in NOx sources and chemistry since 1760 to much less than the thickness of a single water molecule so C.E. A marked negative trend in '15N since industrialization

the understanding of the data can only be founded in (pre-industrial-era average of 12.0‰ vs. air N2 to a modern- mechanisms involving ions and their behaviour specifically, at era average of 3.6‰) parallels a nearly three-fold increase in the molecular scale. nitrate concentration, as well as pronounced increases in tracers such as excesss lead and non-sea-salt sulfur. This, along with independent estimates of oil burning and transport studies, indicate that North American oil combustion is the 15 primary driver of the negative trend in $ N of nitrate. The pre-industrial record of nitrate and tracers such as amonium 15 and black carbon ties the high, positive $ N values to biomass 15 burning. Overall, this record provides constraints for $ N-

NOx source signatures, which are poorly characterized. A quantitative tracer of the pre-industrial sources and chemistry

of NOx would allow for detailing connections between the atmosphere (lightning, chemistry, transport), the biosphere (biomass burning, soils), and climate.

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Rare Earth Elements in the surface Hydrogeochemical assesment of Ocean under the Saharan dust belt Pasinler (Erzurum- Turkey) ED C. HATHORNE1, MARTIN FRANK1, MICHIEL RUTGERS geothermal fluids 2 2 3 VAN DE LOEFF , TOBIAS ROESKE , AND JOERG RICKLI 1 1 1 E. HATIPOGLU *, F. GULTEKIN AND A. FIRAT ERSOY 1 GEOMAR, Helmholtz Centre for Ocean Research Kiel, 1 Karadeniz Technical University, 61080 Trabzon, Turkey Germany ([email protected]) (*correspondence:[email protected], 2Alfred Wegener Institute for Polar and Marine Research [email protected], [email protected]) (AWI), Bremerhaven, Germany 3ETH Zürich, Switzerland The Pasinler geothermal field is located to 37 km east of The supply of trace metals to the surface ocean via dust Erzurum Province. The basement of Pasinler Geothermal field deposition is important for primary productivity and the global consists of Upper Cretaceous ophiolitic melange, Eocene biogeochemical cycle of many elements. Here we utilise the volcanic rocks, Oligocene volcanic rocks, Lower Miocene reef systematic variation of the chemical properties of yttrium and limestones, Upper Miocene pyroclastics, Plio-Quaternary the rare earth elements (YREE) to investigate trace metal (sandstone, marl, conglomerate) and Quaternary alluvium. release from dust in the equatorial Atlantic Ocean. We present The rhyolite is the reservoir for the geothermal fluid. The tuffs YREE data for the dissolved (<0.45 µm) and suspended and marls are cap rocks of the system. The fault and related particulate matter (SPM) collected from the mixed layer fractures around the Pasinler geothermal field provide during Polarstern cruise ANT-XXIII/1 in Oct-Nov 2005. pathways for the upward flow of geothermal fluid to the Saharan dust can be traced with the Al content of the SPM surface. The Alluvium around the Hasankale River is the most revealing a broad maximum extending from 15° to 3°N. The important unit as cold groundwater deposits in the study area. PAAS normalised YREE patterns of the dust dominated SPM The thermal waters in the Pasinler geothermal fields have are relatively flat with a broad peak centred around Eu and outlet temperatures 23 to 35°C in springs. But discharges in Gd. This dust dominated SPM is also characterised by lower the wells vary between 38-52°C. Y/Ho and Er/Nd ratios than the particulate material from Geothermal well waters belong to the Na-Ca-Cl-HCO3 outside the high Al zone. type. The Pasinler geothermal water has discharge pH values The dissolved YREE distributions show normal seawater of 6 to 7.5, electrical conductivity (EC) of 970 to 5800 %S/cm patterns with the relative enrichment of heavy REE over light and TDS contents between 635 and 3700 mg/l. The Pasinler REE. The samples with dust dominated SPM are enriched in geothermal field is in class low enthalpy geothermal system, the light and middle REE by a factor of approximately 2 and its reservoir temperature was calculated as 46-169°C 18 2 compared to the other samples and a Sargasso Sea surface using silica geothermometer. The ' O- ' H data clearly water. The dissolved Y/Ho and Er/Nd ratios obtained from the indicate a meteoric origin for the thermal waters. dust dominated SPM zone are also low compared to the According to analyses of heavy metal contents such as Cr, samples outside the zone but display a fractionation between Pb, Zn, Ni, Al and Cu, the Pasinler geothermal water is the SPM and the dissolved phase. This comparison indicates a suitable for the Turkish Thermal Standarts, on the other hand consistent incongruent dissolution of the dust associated by the amount of Fe, Mn, As, B, Br is not suitable. YREE which are probably mainly hosted by oxide coatings on the particles.

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Laser ablation for spatially resolved SO2 photoexcitation links polar radiocarbon measurements with gas sulfate and climate-impacting source-accelerator mass spectrometry volcanism B. HATTENDORF1, C. MÜNSTERER1,2, R. DIETIKER1, SHOHEI HATTORI1*, JOHAN A. SCHMIDT2, J. KOCH1, L. WACKER2, M. CHRISTL2, H.A. SYNAL2 AND MATTHEW S. JOHNSON2, SEBASTIAN O. DANIELACHE3, D. GÜNTHER1 AKINORI YAMADA4, YUICHIRO UENO5,6 1,6 1 AND NAOHIRO YOSHIDA ETH Zurich, Laboratory for Inorganic Chemistry, Wolfgang Pauli Str. 10, 8093 Zurich, Switzerland 1 Department of Environmental Chemistry and Engineering, 2 ETH Zurich, Laboratory of Ion Beam Physics, Tokyo Institute of Technology, Japan Schafmattstr. 20, 8093 Zurich, Switzerland ([email protected]) 2Department of Chemistry, University of Copenhagen, Accessing the spatial variability of 14C in solids like for Denmark example speleothems, corals or wood, traditionally required 3Faculty of Science & Technology, Sophia University, Japan laborious and time consuming sample preparation (milling, 4Department of Earth & Planetary Science. University of drilling, graphitization) to allow measurements by accelarator Tokyo, Japan mass spectrometry (AMS). With the availability of gas ion 5Department of Earth & Planetary Sciences. Tokyo Institute of source AMS [1] and new sample preparation techniques and Technology, Japan 6 the direct measurement of gaseous carbon species (i.e. CO2) a Earth-life Science Institute (ELSI), Tokyo Institute of wider range of applications has become accessible. Laser Technology, Japan

ablation can directly produce CO2 from carbonates at a spatial resolution of several 10 µm and is considered to complement Natural climate variation, such as that caused by currently available measurement strategies when high volcanoes, is the basis for identifying anthropogenic climate resolution radiocarbon records are of interest. In this study, a change. However, knowledge of the history of volcanic prototype laser ablation sampling unit is developed, which can activity is inadequate, particularly concerning the explosivity be directly connected to the ion source of a gas-source AMS of specific events. Some material is deposited in ice cores, but instrument. It comprises an ArF excimer laser (193 nm) with the concentration of glacial sulfate does not distinguish beam delivery optics, a specific ablation cell and sample between tropospheric and stratospheric eruptions. Stable sulfur observation system. Initial tests showed that using rectangular isotope abundances contain additional information, and recent ablation crater of 100 µm x 700 µm can generate a sufficient studies show a correlation between volcanic plumes that reach

CO2 flux to allow radiocarbon measurements with the gas ion the stratosphere and mass-independent anomalies in sulfur source AMS. The ablation cell was designed in order to avoid isotopes in glacial sulfate. We describe a mechanism,

carry over effects of particulate debris from adjacent ablation photoexcitation of SO2, that links the two, yielding a useful spots and to ensure minimum signal dispersion at the metric of the explosivity of historic volcanic events. A plume operating conditions of the gas source AMS (i.e. 200 µL/min model was constructed including photochemistry, entrainment He as carrier gas). It consists of a volume-optimized gas of background air, and sulfate deposition. - expansion head with targeting and observation window and a specifc photoexcitation rates were calculated based on the UV 32 33 34 36 large volume sub-unit capable of hosting sample specimen absorption cross-sections of SO2, SO2, SO2, and SO2 with sizes of up to 100 mm x 20 mm. The system from 250 to 320 nm. The model shows that UV configuration and initial results from 14C measurements will photoexcitation is enhanced with altitude, whereas mass-

be discussed in this presentation. dependent oxidation, such as SO2 + OH, is suppressed by in situ plume chemistry, allowing the production and [1] Ruff M. et al, A GAS ION SOURCE FOR preservation of a mass-independent sulfur isotope anomaly in RADIOCARBON MEASUREMENTS AT 200 kV, the sulfate product. We are able to identify the process RADIOCARBON, Vol 49, Nr 2, 2007, p 307–314 controlling mass-independent sulfur isotope anomalies in the modern atmosphere. This mechanism is the basis of identifying the magnitude of historic volcanic events.

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Internal structure of a mid-crustal The effect of hydrothermal iron on magmatic conduit: The Punta marine dissolved organic carbon Falcone mafic pluton (Sardinia, Italy) J. A. HAWKES*1, D. P. CONNELLY1, A. DJURHUUS2 AND 1 1 2 E. P. ACHTERBERG ANNE-CÉCILE HAUSER AND FRANÇOIS BUSSY 1 1,2 National Oceanography Centre Southampton, European Way, Institute of Earth Sciences, University of Lausanne, Southampton, UK Géopolis, CH-1015 Lausanne. 2University of Oxford, Department of Zoology, South Parks ([email protected], [email protected]) Road, Oxford, UK

The granite-hosted mid-crustal gabbroic pluton of Punta High temperature hydrothermal vents produce particle rich Falcone is built by many magmatic pulses with contrasting plumes in particle deprived deep ocean regions. Dissolved textures and composition. Gabbros can be divided into a organic carbon (DOC) may be adsorbed onto this iron rich supposedly older external zone (EZ) and a central zone (CZ) particulate matter and as a result hydrothermal plumes may act based on mineralogical, textural and geochemical arguments. as a sink for DOC [1]. It is estimated that the ocean’s water is CZ gabbros are more primitive in composition as indicated cycled through hydrothermal plumes on a 4000-8000 year e.g. by higher mg-# in amphiboles. They contain relics of timescale [2], making even very small DOC concentration orthopyroxene, which are absent in the EZ gabbros. Whether changes in plume waters significant to the ocean budget of the change in chemistry is due to more thorough interaction of DOC. With an increasing variety of venting types being the earlier pulses (EZ) with the host rocks during ascent/in the discovered [3,4], including environments which produce new source region or whether it represents a change in the magma DOC from magmatic CH and CO [5,6,7], a deeper source should be resolved by radiogenic isotope compositions. 4 2 understanding is required to assess the impact of hydrothermal High An-contents of plagioclase as well as important vents on marine DOC. amounts of amphibole in all gabbros express the high water We present new carbon and iron concentration data from content of the system. Phase diagrams based on water- plumes in three different hydrothermal settings: a back-arc saturated experiments allow linking the early stabilization of vent site, a deep mid ocean ridge vent site and a ocean core amphibole in the EZ gabbros (sub-euhedral grains) with complex hosted vent site. The plume characteristics (physical cooling of the magma during ascent. The later appearance of and chemical) are very different at these three sites, and amphibole in the CZ gabbros (poikilitic interstitial phase samples were taken from vent fluids, diffuse areas of venting, around euhedral plagioclase) on the other hand indicates the buoyant plumes and the dispersing (neutrally buoyant) higher temperatures for the same pressure and thus thermal plumes, allowing a comprehensive description of the maturation of the system over time. Furthermore the first interactions between dissolved and particulate iron and carbon pulses (EZ) crystallize as a whole with isotropic granular in these three high-temperature vent environments. We will textures, whereas later pulses (CZ) show signs of crystal use the results to consider the overall impact that hydrothermal segregation and cumulate processes. They display remarkable venting has on the concentration and nature of marine organic rhythmic black and white layering at the cm-scale, which is carbon globally. roughly vertical and parallel to the limits of the cooling units.

A second set of layers is crosscutting the main one at an angle [1] Bennett et al (2011), Deep Sea Res. I 58, 922-931. of ca. 35°. Dark bands are defined by interstitial amphibole, [2] Elderfield & Schultz (1996), Annu. Rev. Earth Planet. Sci. which is absent in the white layers. The amount of lost liquid 24, 191–224. [3] Kelley et al (2005), Science 307, 1428-1434. might reach several tens of wt%. The concentration of late [4] Connelly et al (2012), Nat. Comm. 3 no.620. [5] Bennett et crystallizing amphiboles in the dark layers indicates that liquid al (2011), Geochim. Cosmochim. Acta 75, 5526-5539. extraction is possibly linked to the development of the [6] Lang et al (2010), Geochim. Cosmochim. Acta 74, 941- layering. 952. [7] Lang et al (2006), Geochim. Cosmochim. Acta 70, We interpret these magmatic structures as resulting from 3830-3042 shearing of a crystallizing mush during its ascent or at its final

emplacement level, with concomitant extraction of residual liquid, which escaped to higher crustal levels.

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Assessing the influence of glacial Exhalation and inhalation of Cera weathering on marine iron (Fe) lattice Oxygen: A triple Oxygen inputs using Fe stable isotopes isotope persective S.M. HAWLEY1*, H.M. WILLIAMS1, P.A.E. POGGE VON JUSTIN HAYLES1 AND HUIMING BAO1 2 3 1 STRANDMANN , S.R. GISLASON AND K.W. BURTON 1 Department of Geology and Geophysics, Louisiana State 1Durham University, Durham DH1 3LE, UK (correspondence: University, Baton Rouge, LA 70803 ([email protected]) [email protected], [email protected],

[email protected] Ceria (CeO2) is a fluorite type oxide that has been studied 2 University of Oxford, Oxford, OX1 2JD,UK and used extensively as an oxygen storage media in three-way ([email protected]) catalysts, as an oxygen partial pressure regulator, as a fuel 3 University of Iceland, Reykjavik, 101 Reykjavik, Iceland additive for the reduction of soot, and for the production of

([email protected]) syn-gas from water and CO2. It is known that exposing ceria powders to low pO2 and/or high temperature conditions will Marine concentrations of bioavailable and reactive Iron cause ceria to partially reduce. This partial reduction drives off can modulate the Carbon cycle and Earth’s climate [1,2] oxygen from crystal lattice (exhalation) and leads to the Previous studies of glacial weathering [3,4] suggest that formation of oxygen vacancies. When partially reduced ceria biogeochemical processes at rock-glacier interfaces promote is exposed to high pO2 environments, such as open air, the the formation of highly bioavailable and reactive nano- ceria powders will readily reoxidize even at room temperature. particulate iron oxy-hydroxides. Consequently, because glacial The reoxidation effectively fills the oxygen vacancies with weathering is a climatically dependent process the marine new oxygen (inhalation). We expect that oxygen isotope export of glacially derived oxy-hydroxide should strengthen fractionation is associated with both the exhalation and the the feedback loop between Fe and the climate. inhalation processes. Understanding the isotope effect will Iron stable isotopes ('57Fe) have potential to trace help us explore the molecular mechanism for the dissociation, weathering Fe exports as Fe oxy-hydroxide formation has association, migration of oxygen on the surface and within the been shown to fractionate Fe stable isotopes [5]. Preliminary lattice of ceria. data from Kangerlussuaq, Greenland indicates suspended To determine this isotope effect, we have devised an particulate and dissolved material have heavy '57Fe values experimental procedure utilizing triple oxygen isotope labelled (~0.20 permil) compared to the surrounding bedrock and initial ceria powders. These powders are heated (700°C) for riverine bed loads (-0.10 to 0.00 permil). This study will one hour and cooled under vacuum prior to exposure to air. By incorporate further Fe isotope data from glacial and non- combining the results from six independent experimental sets glacial catchments in Iceland and Greenland. Both Iceland using different initial oxygen isotope labels we have and Greenland contain glacial and non-glacial systems that determined the kinetic isotope fractionation factors for both drain relatively uniform rock types allowing for the effects of exhalation and inhalation using a graphical method. Our the different weathering regimes to be compared. results indicate that there is a 1.6‰ ±0.6‰ increase in the 18 Comparisons between Greenland and Iceland then allow ' O value of the remaining ceria upon heating in vacuum. independent assessment of the role bedrock plays in When the vacuum is broken at room temperature, the heated 18 controlling Fe exports from glacial and non-glacial ceria will inhale 3% to 12% oxygen from air, with a ' O of weathering. 1.6‰ (+4.6‰; "5.6‰). These fractionation factors are consistent with the magnitudes of kinetic fractionation [1]Martin (1990) Paleoceanography, 5(1), 1-13. [2]Lalonde et associated with the dissociation and association of atomic al (2012) Nature, 483, 198-200 2012.[3] Raiswell et al (2006) oxygen at the surface of ceria. The issue associated with room- Geochem. Cosmo. Act. 70, 2765-2780.[4] Wimpenny et al temperature oxygen inhalation renders ceria a poor choice of (2011) EPSL 290, 427-437 [6] Severmmann et al (2008) exchange medium for triple oxygen isotope analysis of CO2 or Geology 36, 487-490. other oxygen-bearing gases. We have discovered a similar result for yttria stabilized zirconia as well, suggesting that this behaviour may be intrinsic to the fluorite type oxides.

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Contrasting tourmaline chemistry Earth’s Carbon through from late-Archaen orogenic gold ROBERT M. HAZEN deposits at Hutti and Hira-Buddini, Geophysical Laboratory, Carnegie Institution of Washington, eastern Dharwar craton, India: 5251 Broad Branch Rd NW, Washington DC 20015 USA. ([email protected]) Implications for fluid source 1 1 Earth’s 4.567 billion year history is marked by a dramatic PRANJIT HAZARIKA *, BISWAJIT MISHRA 1 evolution in the chemical, physical, and biological roles of AND KAMAL LOCHAN PRUSETH carbon [1,2]. Aspects of Earth’s changing carbon cycle are 1 Department of Geology and Geophysics, Indian Institute of revealed by a variety of investigations, including: (1) Abiotic Technology, Kharagpur, India-721302 organic systhesis, notably mineral catalyzed reactions of (correspondence:[email protected]) volcanic gases, yield essential biomolecules. Recent findings point to the critical role played by hydrogen fugacity in the Textural and chemical features of tourmaline in the synthesis and stability of these molecules [3]. (2) Small proximal alteration zones of the Hutti and Hira-Buddini organic molecules display competitive and cooperative deposits are: (i) warping of biotite-chlorite mylonitic foliation, adsorption on mineral surfaces. We find that adsorption (ii) inclusions in pyrite, and (iii) sharp decrease of Fe at rim. configurations are strongly affected by environmental These imply (i) synchronous sulfidation of the wall rocks conditions such as pH, ionic strength, and solute concentration resulting in pyrite formation and (ii) early tourmalinization [4]. (3) Experimental, theoretical, and field studies elucidate and its continuation until sulfidation of wall rocks and gold serpentinization reactions, as well as other deep interactions mineralization. between C-bearing fluids and mafic and ultramafic rocks. Tourmalines from Hutti are Mg-rich (XMg=0.63) while the Both volcanic and impact hydrothermal zones led to the first unaltered rock is Fe-rich (XMg=0.30). Their high Al content (> extensive carbonate mineral production [5]. (4) The +3 6 apfu) implies no substitution of Al by Fe in the Z-site. The subsurface biosphere modifies and cycles carbon. Deep +2 dominant substitutions observed are MgFe "1, and microbial life often survives at metabolic rates and in +2 +2 %AlNa"1(Fe ,Mg)"1. Participation of Fe in most substitutions concentrations far below those of near-surface communities +3 +2 suggest a low Fe /Fe ratio, also supported by the [6]. And (5) carbon mineral evolution traces the changing compositions lying on the dravite-foitite trend. These diversity, distribution, and compositions (including trace and observations suggest a reducing nature for the tourmaline minor elements) in carbon minerals through deep time. precipitating fluid. The Mg-rich composition of tourmaline in Diamond was the first mineral in the cosmos, but many of the Fe-rich amphibolite shows insignificant chemical control of almost 400 known carbon minerals have appeared only the unaltered rock on the tourmaline chemistry and suggest recently in Earth history [7]. Collectively, these and other their formation under high fluid by rock ratio [1]. Such Mg- investigations of Earth’s carbon through deep time underscore rich, low saline (X-site vacancy upto 0.53) and reducing the co-evolution of the geosphere and biosphere. nature of the fluid is suggestive of a metamorphic source [1][2]. [1] R.M.Hazen, A.P.Jones & J.A.Baross [Eds] (2013) Carbon Tourmalines from Hira-Buddini belong to dravite-schorl in Earth. Rev. Mineral. Geochem. v. 75, 698 p; [2] R. series with relaively low Mg (XMg=0.53); low X-site vacancy Dasgupta (2013) Ingassing, storage, and outgassing of (. 0.16) and show an oxy-dravite-povandrite (O-P) trend. terrestrial carbon through geologicl time. Rev. Mineral. +3 Dominant substitutions observed are Fe Al"1, Geochem. 75, 183-229; [3] M.A.Sephton & R.M.Hazen +2 +3 Fe Fe (Al"1Mg"1) and minor NaMg(%"1Al"1). Al contents of (2013) On the origins of deep hydrocarbons. Rev. Mineral. < 6 apfu is possibly due to substitution of Al in the Z-site by Geochem 75, 449-465; [4] H.J.Cleaves et al (2012) Mineral- +3 Fe , as evident from the substitution types and tourmaline organic interfacial processes: Potential roles in the origins of compositions lying on the O-P trend. Tourmalines life. Chem. Soc. Rev. 41, 5502-5525; [5] M.O.Schrenk et al +3 characterized by enrichment in Fe and Na, depleted in X-site (2013) Serpentinization, carbon and deep life. Rev. Mineral. vacancy suggest oxidizing and relatively high saline fluid, Geochem 75, 575-606; [6] F.S.Colwell & S. D’Hondt (2013) which could be either from a meta-evaporitic [3] or a late Nature and extent of the deep biosphere. Rev. Mineral. stage granitic source [4]. Geochem 75, 547-574; [7] R.M.Hazen, et al (2013) Carbon mineral evolution. Rev. Mineral. Geochem 75, 79-107. [1] Jiang et al (2002), Chem Geol 188, 229-247. [2] Groves and Phillips (1987), Ore Geol Rev 2, 287-322. [3] Cabral et al (2012), Lithos 140-141, 224-233. [4] Henry and Dutrow (2012), Lithos 154, 16-32.

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Paleomineralogy of the Hadean Eon Role of bacteria on the release of ROBERT M. HAZEN cesium from illite Geophysical Laboratory, Carnegie Institution of Washington, ALICE HAZOTTE1*, THIERRY LEBEAU1, OLIVIER PÉRON2, 5251 Broad Branch Rd NW, Washington DC 20015 USA. TAKUMI SAITO3 AND ABDELOUAS ABDESSELAM2 ([email protected]) 1LUNAM University, LPGN, UMR 6112, BP 92208, 44322

Nantes, France (*[email protected]; The Hadean Eon, encompassing Earth’s first 550 million [email protected]) years, was a time of significant planetary evolution. 2Subatech, UMR 6457, BP20722, 44307 Nantes, France Nevertheless, prebiotic Earth’s near-surface environment may ([email protected]; have held no more than approximately 420 different rock- [email protected]) forming or accessory mineral species that were widely 3 Department of Nuclear Engineering and Management, distributed and/or volumetrically significant [1]. This relative School of Engineering, The University of Tokyo, Japan Hadean mineralogical parsimony is a consequence of the ([email protected]) limited modes of mineral paragenesis prior to 4 Ga compared to the last 3.0 billion years. Dominant Hadean Eon As a result of the nuclear accident in Fukushima, various mineralizing processes include the evolution of a diverse suite radioactive elements such as cesium were dispersed in the of intrusive and extrusive igneous lithologies; hydrothermal atmosphere before being deposited on the soil within a alteration over a wide temperature range, notably distance of 80km around the nuclear power plant. Cesium with serpentinization; authigenesis in marine sediments; diagenesis half-life of 30 years and properties similar to potassium and low-grade metamorphism in near-surface environments; accumulates in the clays, especially illite, of the upper soil and impact-related processes, including shock mineralization, horizons. creation of marginal hydrothermal zones, and excavation of Among soil remediation methods, phytoextraction is the deep metamorphosed terrains. On the other hand, the Hadean most appropriate one as it can be achieved in situ without any Eon may have been notably lacking in mineralization change of the biophysicochemical properties of the soil. generated by plate tectonic processes, such as subduction zone Cesium uptake by plants depends on sorption/desorption volcanism and associated fluid-rock interactions, which result reactions to/from the soil particles and on biogeochemical in massive sulfide deposition; convergent boundary orogenesis processes in the rhizosphere. and consequent extensive granitoid-rooted continental This work focuses on the bacterial mechanisms involved landmasses; and the selection and concentration of in Cs desorption from illite by estimating the amount of Cs incompatible elements in complex pegmatites, with hundreds released by desorption and/or as the result of illite alteration. of accompanying minerals. The dramatic mineralogical Citric acid and oxalic acid that bacteria and plants are able to consequences of life are reflected in the absence of Hadean produce in soils were used in this work [1-2]. Illite alteration biomineralization; for example, the lack of extensive by these same bacteria also able to form biofilms at the surface carbonate deposits and the associated restricted development of soil particles was studied [3-4]. Eventually experimental of skarn and cave minerals prior to 4 Ga. Most importantly, it results were compared to those obtained by modeling. was not until after the establishment via photosynthesis of

significant near-surface redox gradients that supergene [1] Krebs, Brombacher, Borrhard, Bachofen ans Brandl alteration, redox-controlled ore deposition, and subaerial (1997), FEMS Microbiology Reviews 20, 605-617. [2] Vyas weathering in an oxidizing environment could diversify and Gulati (2009), BMC Microbiology 9, 174. [3] Alimova, Earth’s near-surface mineralogy. These post-Hadean processes Katz, Steiner, Rudolph, Wei, Steiner and Gottlieb (2009), may be responsible for more than 4000 of the more than 4800 Clays and Clay Minerals 57-2, 205-212. [4] Dong (2012), approved mineral species. Any scenario for life’s origins that Elements 8, 113-118. invokes minerals as agents of molecular synthesis, selection,

protection, or organization must take into account the limited mineralogical repertoire of the time.

[1] R.M.Hazen (2013) Paleomineralogy of the Hadean Eon: A preliminary list. American Journal of Science, in press.

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Multiple exsolutions in a rare Noble gases in mantle xenoliths from clinopyroxene megacryst from the the Tan-Lu fault zone, Hannuoba basalt, North China: North China Craton Implications for subducted slab- HUAIYU HE, FEI SU AND RIXIANG ZHU related crustal thickening and Institute of Geology and Geophysics, Chinese Academy of recycling Sciences, Beijing 100029, China

DETAO HE, YONGSHENG LIU*, XIRUN TONG, KEQING The Tan-Lu fault zone, which extends NNE-SSW for ZONG, ZHAOCHU HU, SHAN GAO more than 3000km, is a major lithospheric discontinuity along Faculty of Earth Sciences, China University of Geosciences, the eastern Asia continent and is believed to have acted as a Wuhan, 430074, China (*correspondence: major channel for the ascending of asthenosphere and played [email protected]) an important role in the Mesozoic-Cenozoic thinning of the North China Craton (NCC) lithosphere. From North to South, A rare large clinopyroxene megacryst (type 1) collected there are many Cenozoic volcanic areas which are located in from the Hannuoba basalt, North China was studied. It is the Tan-Lu Fault Zone. Ultramafic xenoliths, mainly lherzolite distinguished from the prevalent clinopyroxene megacrysts and pyroxenite, are common in alkali basalts in these volcanic (type 2) by garnet and orthopyroxene exsolutions and by areas. Detailed petrological and geochemical studies suggest chemical and Sr-Nd isotopic compositions. The type 1 that these low Mg# peridotites (Fo 88-91) represent fragments clinopyroxene megacryst has higher Cr (2100 ppm) and Mg# of the newly accreted lithospheric mantle. (83) than the type 2 clinopyroxene megacrysts as well as more This study performed a comprehensive investigation of evolved Sr and Nd isotopic compositions. These petrology, mineral chemistry and noble gases of mantle characteristics suggest that the type 1 clinopyroxene xenolith in Changle-Linqu (in the middle part of Tan-Lu Fault megacryst could have been formed by a recycled crust-related Zone) and Nvshan (in the south part of Tan-Lu Fault Zone) melt-peridotite reaction. The type 2 clinopyroxene megacrysts and try to trace the post destruction evolution of North China exhibit good correlations between Mg# and major and trace Craton (NCC) lithospheric mantle. in wehrlites and lherzolites in Changle-Linqu and element compositions. Their Sr-Nd isotopic compositions 3 4 cluster in the least evolved field of the Hannuoba basalt. These Nvshan yield He/ He ratio range from 6.9 to 7.6 Ra, a little observations imply that the type 2 clinopyroxene megacrysts bit lower than MORB value (8±1Ra), suggest that lithospheric were crystallized from the host lava at high pressure. mantle in the Tan-Lu fault zone would thus most likely have The type 1 clinopyroxene megacryst contains abundant been metasomated by melts/fluids derived from an coherent cryptocrystalline lamellaes and orthopyroxene asthenospheric reservoir or lithospheric mantle is cooling from asthenospheric. However, wehrlites and lherzolites have exsolutions within it. The bulk composition of the 3 4 cryptocrystalline lamellaes, composed of fine plagioclase and significant lower He/ He ratios, lower helium abundance and lower 4He/40Ar* in Cpx than in co-exist Ol. 4He abundance olivine, shows typical chemical features of garnet and Sr 3 4 isotopic composition similar to the clinopyroxene host. These and He/ He ratios of Opx are lower than co-exist Ol and observations indicate that the cryptocrystalline lamellaes are higher than co-exist Cpx. Our thin section study indicates there is a direct link between sieve texture/melt-pocket and decomposition products of garnet exsolutions in the 3 4 4 40 clinopyroxene megacryst. This garnet exsolution could be low helium abundance, low He/ He ratios and low He/ Ar*. caused by increasing pressure or decreasing temperature, as This may suggest that the noble gas in Cpx were lost during partial melting and there is diffusive fractionation between indicated by experimental results. Although the temperature 3 4 40 decreases during basalt eruption, the much quicker decrease in He, He, and Ar. pressure will suppress the garnet exsolution in clinopyroxene. Therefore, we suggest that the type 1 clinopyroxene megacryst could have experienced pre-Mesozoic crustal uplifting and thickening at the north margin of the North China Craton. Garnet decomposition could have taken place prior to orthopyroxene exsolution during the eruption of the host lava.

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Novel bionanocomposites - Chitosan C4 plants expansion and the Goethite Bead - for arsenic enhanced aridity from the late remediation Miocene to Pliocene on the Chinese J. HE1,2, F. BARDELLI1, A. GEHIN1 AND L. CHARLET1* Loess Plateau 1ISTerre, Université Joseph Fourier (Grenoble), P.O. Box 53, TONG HE, YANG CHEN, JUNFENG JI* F 38041 Grenoble, France, The MOE Key Laboratory of Surficial Geochemistry, School (*correspondence:[email protected]) of Earth Sciences and Engineering, Nanjing University, 2School of Resource and Environmental Science, Wuhan Nanjing 210093, China (*Correspondence: University, Wuhan 430079, PRC [email protected])

Since iron oxides/hydroxides have high sorption affinity The Red Clay Formation, which underlies the well-known toward both As(V) and As (III), many scientific and industrial Quaternary loess sequence, extends the eolian deposits from researches focus on the application of iron oxides/hydroxides 2.6Ma through the late Miocene making it a good archive to as adsorbents in water treatment. Nevertheless, most iron reconstruct Pliocene climate in North China. The carbon oxides/hydroxides are fine powders, difficult to separate from isotopic compositon of carbonate nodules in the Red Clay solution after the adsorption process. In this study we develop Formation has been suggested as potential proxy for a novel method for the synthesis of chitosan-iron hydroxide paleoecology. The spatial and temporal pattern of carbon composite leading to chitosan-goethite bead (CGB). Goethite isotopes will provide new evidence for the drying history from nanoparticles and chitosan gel-beads were prepared late Miocene to Pliocene. simultaneously, obtaining 1mm-sized spherical We studied four continuous sections (Duanjiapo, Lingtai, bionanocomposites, consisting of homogenous distribution of Bajiazui and Jiaxian) of the Red Clay Formations on Chinese the goethite nanoparticles in the chitosan phase with enhanced Loess Plateau (CLP) by stable isotope mass spectrometer. The mechanical properties compared to pure polymer/pure averages of carbon isotopes were at -9.3‰, -8.0‰, -5.3‰ and mineral. The macroscopic structure of the composite -4.9‰, respectively. The carbon isotopes of carbonate nodules determines that it can overcome the difficulty of separation show a northward positive gradient on CLP, suggesting an procedure in water treatment, while its microscopic structure increasing trend of C4 plants abundance, which may relate retains the superiority of nanomaterial with regard to high with increasing aridity. sorption efficiency. CGBs were characterized by Mössbauer Two C4 plants expansion events were revealed from our spectroscopy to confirm the presence of goethite phase, and Red Clay carbon isotope records. C4 plants greatly expanded their morphology was investigated by FE-SEM. Batch in two intervals at ~6.4Ma and ~3.6Ma on CLP. The enhanced sorption and kinetic experiments on CGB reactivity toward aridity may account for the two events. arsenate and arsenite were performed to quantify the sorption and diffusion-controlled kinetics of CGB with respect to As. Acknowledgment In addition, the mechanism of arsenic uptake onto CGB was This study is funded by the NSF of China (Grant No. investigated by X-ray Absorption Spectroscopy (XAS), and 41021002 and 41230526). the diffusion of As(V) and As(III) from aqueous into solid phase was monitored by micro X-ray fluorescence (µXRF) (Fig.1) and micro X-ray Absorption Near Edge Spectroscopy (µXANES).

Figure 1. Color temperature distribution maps of As (green color) and Fe (red color) of As-loaded CGB samples, collected from kinetic experiments of As(V) sorption onto CGB a) at 1.5 h, b) at 120 h; As(III) sorption onto CGB c) at 1.5 h; d) at 120 h.

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A thermodynamic entrapment model Tawlah Specialized Alkaline Granite for the quantitative description of Prospect, Midyan Region, Arabian selenite coprecipitation with calcite Shield, Kingdom of Saudi Arabia: F. HEBERLING1*, V.L. VINOGRAD2,3, R. POLLY1 Petrology. Structural Implications 1 Karlsruhe Institute of Technology, Institute for Nuclear and REEs-RM Characterization Waste Disposal, Karlsruhe, Germany, 1 2 MOHAMED TH.S. HEIKAL AND MAHER A. AMMAWY [email protected] 2 Forschungszentrum Jülich, Institute of Energy and Climate 1Geology Department, Faculty of Science, Tanta University, Research-6, Jülich, Germnany Tanta 31527, Egypt 3 Goethe Universität Frankfurt, Institute of Geosciences, ([email protected]) Frankfurt, Germany 2Geology Department, Faculty of Science, Benha University, Egypt The trace element Selenium is of environmental relevance as a nutriant as well as a toxic element for animal and human The Tawlah albite granites-quartz synites is one of 79 life. The long lived fission product Se is of special concern promising sites of REE- Ta-Nb- bearing alkaline granites in in the context of nuclear waste management. the Midyan Suite, NW Arabian Shield. The granite-syenite A possible retention mechanism for selenite in natural association is a highly lecucratic, albite-rich rocks with environments is the structural incorporation of the trigonal accessory columbite-tantalite, thorite, monazite, allanite, 2- pyramidal oxyanion Se(IV)O3 into the calcite structure. xenotime, zircon and cassiterite. Ages of 577± 4 Ma (Hedge, EXAFS and polarization dependent EXAFS 1985) were obtained from isotopic ratios of Sr and Nd by measurements confirm, in agreement with previous results [1], 143Nd/144Nd and 87Sr/86Sr method. The precision is sufficient to the structural incorporation of selenite in calcite and the indicate that the albite granite is post-orogenic with respect to substition of carbonate for selenite, leading to the formation of Najd orogeny. The Tawlah granite is divided into abite-granite a Ca(SeO3)X(CO3)(1-X) solid solution. (in major) and quartz-syenite (in part). The albite granite is Selenite incorporation, quantified in coprecipitation more highly mineralized, has higher modal albite contents and experiments at surface controlled steady state conditions and higher Nb/Ta ratios, both in whole surface rocks and in drill low supersaturation, is much higher (partition coefficient, Dexp hole samples. = 0.015±0.012) than expected according to DFT calculations On the structural point of view, the relationship between -10 and thermodynamic considerations (Dtheo = 2·10 ). fault system and/or shear zones reported and mineral potential To bridge the gap between experiment and theory we provides excellent and interesting evidences of its occurrence. present a thermodynamic entrapment model based on the Bearing in mind the Najd fault zone provides interesting assumption, that experimental observations reflect preferential evidences concerning the relationship between such faults and incorporation of selenite into the calcite surface and REEs-Nb-Ta-Th mineralization. Therefore, the distribution of subsequent entrapment upon crystal growth, while bulk DFT mineralizations are closely related to the main trends; WNW- calculation reflect the high strain induced upon incorporation ESE, NW-SE and ENE. On the other hand, reactivation of of selenite into the bulk calcite structure. NW Najd fault system has been affected by Teriary rift DFT calculations confirm that surface incorporation is tectonics, leading to the development of mineralization in energetically more favourable than bulk incorporation. Batch Tawlah alkaline granites. type adsorption experiments at calcite equilibrium confirm the On the basis of petrographic, mineralogical signature and analogy between surface adsorption (ion-exchange [2]) and geochemical interpretations, it is suggested that the albite coprecipitation. granite-quartz syenite of Jabal Tawlah has a magmatic origin The observation of growth inhibition in aragonite to indicating post-orogenic overprinting of A-type granites. By calcite recrystallization experiments in the presence of selenite analogy with other Nb-Ta-REEs –bearing granites, the sodic in solution is interpreted as experimental evidence for the bulk composition of Tawlah granite can be explained by energetical difference between bulk and surface incorporation fluorine enrichment in the magma, but much of the magmatic of selenite in calcite. fluorine was lost upon crystallization because the low CaO,

P2O5 and Al2O3 contents of melt precluded fixation of F in [1] Aurelio et al Chem. Geol. 270, 2010, 249-256. [2] Cheng crystalline phases. et al Surf. Sci. 283, 1997, L690-L695 In fact, the Tawlah alkaline granite prospect is considered to be a promising metallogenic site for REEs and Nb-Ta-Th, where its geologic environment, structural framework and tectonic setting are reasonable for achievement.

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Why so much gold in the Archean? Changing mantle wedge geometry Some thoughts linking the and magma generation processes in Witwatersrand gold endowment to the Central Andes hydrothermal processes ROSANNE HEISTEK1* AND GERHARD WÖRNER1 CHRISTOPH A. HEINRICH 1GZG, Georg-August Universität, 37077 Göttingen, Germany (*correspondence: [email protected]) ETH Zurich, Department of Earth Sciences, 8092 Zürich,

Switzerland; [email protected] Miocene andesitic volcanoes in the Central Andes typically overly plateau-forming ignimbrites. These “early” Archaean cratons constitute a tiny fraction of today’s andesites form low angle volcanic shield volcanoes succeeded continental surface, but are disproportionately endowed by by more evolved steep-sided strato-cones. These cover smaller gold mineralization, amounting to more than half of the areas and are characterized by amphibole phenocrysts. Such a known economic resources. Through Earth’s history, gold ore transition could be either due to a change in the melting accumulation in veins and shear zones by metamorphic and/or regime in the mantle wedge from decompression (hot and deep-seated magmatic fluids broadly correlates with the rate dry?) to flux melting (wet and lower T?) or to different magma of continental crust formation, both showing a prominent peak production and effusion rates. in the Archean at 3.2 – 2.5 Ga. The Witwatersrand basin in the We studied samples that represent different ages, Kaapvaal Craton also formed in this period, hosting some 40% petrography, composition, and volcanic style in order to test of economic gold ore in fluviatile conglomerate layers that differences in processes of magma generation. Based on a also contain pyrite pebbles, uraninite grains and reduced survey of >4000 chemical analyses (http://andes.gzg.geo.uni- carbon. The enrichment of these minerals within conglomerate goettingen.de/) and the distribution of SiO we selected three layers occurred near the paleosurface, but the mechanism of 2 representative sample types 1) the most mafic samples ( 50-55 gold deposition (clastic or early hydrothermal), the transport % SiO ), 2) the intermediate andesites representing 63 % of medium (fluvial or shallow marine water; mechanical or 2 the data (55 -60 % SiO ) and 3) felsic samples (60-65 % SiO ) chemical) and the source of the gold remain debated. 2 2 which were identified before as important endmember magma Mass-balance estimations indicate that craton-scale type in the Central Andes. Using a range of geothermometers erosion of normal crustal rocks could deliver enough gold to and hygrometers, we show that the most significant produce the Witwatersrand ores. However, if transport and parameters regulating viscosity at the time of eruption enrichment occurred mechanically in placer deposits, this remained surprisingly constant throughout Andean history requires that particles of native gold were available in the (e.g. 940°C to 1020°C for 2 pyroxene thermometry). eroding crust. The process that may have precipitated these Therefore, the rate of effusion, and by implication, magma primary gold particles may well be a critical step in the production and upper crustal stress regime rather than eruption exceptional endowment of Archean crust with economic gold temperature are the primary factors that influenced flow length deposits. In today’s surface environment, most of the and flow field type. hydrothermal flux of gold through the upper crust becomes Another important parameter maybe preferential erosion dispersed, ending up in slightly gold-enriched black shales that of Miocene stratocones relative to distal lava fields. An are liable to recycling, but only locally contribute to later ore increase in slab dip after a time of flat-slab subduction may formation. By contrast, the acid surface environment in increase melt production in the mantle wedge and result a Archean times may have acted as a near-perfect “screen” for change in stress regime in the upper Andean plate. Ensuing the precipitation of all the gold transported upward from the high effusion rates during the Miocene produced lava shields lower crust or the mantle by crust-forming processes. Vein with stacks of long lava flows at the base of (now eroded) deposits in greenstone belts probably trapped only a small steeper stratovolcanoes. Erosion of the central stratocone left fraction of this hydrothermal gold flux, while a far greater isolated lava fields. By contrast, lower melt production and fraction of native gold may have been precipitated near the effusion rates during the Pliocene the Quaternary reflect more land surface, also above widespread granitoids. Gold particles diverse ascent paths and crustal magma systems with more would have been ready for further concentration by diverse cooling, crystallization, assimilation, and mixing mechanical transport into conglomerate reefs, but some direct histories. At the same time, the depth of magma evolution precipitation of dissolved gold by reduction on local organic changed as represented by increasing garnet signatures from material in permeable aquifers may have upgraded the ore. Miocene to Pleistocene lavas.

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Soil heterogeneity and surfactant Noise is now signal: Capturing the desorption influence PAH relevant from the distraction distribution at a tar-contaminated MATTHEW T. HEIZLER1 site 1New Mexico Bureau of Geology, 801 Leroy Place, Socorro, 1 2 NM, 87801, ([email protected]) KATJA HEISTER * AND ANA T. LIMA

1 Lehrstuhl für Bodenkunde, Technische Universität München, It is truly an exciting time for noble gas applications, and 85350 Freising-Weihenstephan, Germany in the particular, precision is undergoing a (*correspondence: [email protected]) revolutionary increase that allows incredible insight into 2 Department of Earth and Environmental Sciences, University complex geological processes. However this improvement is of Waterloo, Waterloo, N2L 3G1, Canada not immediately allowing for new discovery in geo and thermochronology. Removing the impediment towards new A remediation field experiment utilising electroosmosis discovery lies in determining the causes for age scatter that is and a non-ionic surfactant was conducted successfully at the now recorded in most geological samples. Ultra-high precision site of a former asphalt production plant with a long-term tar- age measurements (0.1-0.2 per mil) on individual volcanic oil contamination [1]. After 159 days, the question arose crystals typically show ~0.2% standard deviation thereby whether the scattered distribution of the polycyclic aromatic reducing the MSWD to ridiculously high values. This leads to hydrocarbons (PAHs) was due to soil’s heterogeneity itself or the question “What part of the scattered distribution records to electroosmosis efficacy [1]. In this study, we assess the the geological event of interest?” Cases can be made for the heterogeneity of the soil itself by analysing various soils young part, the middle part and the old part. Accurate young samples with respect to amount and type of organic matter ages can be argued for by interpreting older results to be (OM) and PAH content. No relationship between either contaminated with excess and/or inherited argon. Excluding amount of OM, amount of aromatic carbon and PAH the young part in favor of the old part implies argon loss is the concentrations was observed. A relationship between PAHs cause of inaccurately young grains. Perhaps our planet and tar oil (represented by aromatic carbon) was a priori operates at a high standard deviation and natural variation expected. Hence, soil’s heterogeneity dominated this site caused by a host of mechanisms can be averaged such that the rather than a considerable redistribution of PAHs during the mean value of a scattered distribution remains the preferred electroosmotic treatment. Batch desorption experiments were choice for an event such as eruption. Determining the then carried out with and without 1% Tween 80 on a geological uncertainty for the time of eruption of a scattered representative sample of intermediate OM and PAH content distribution has no obvious value or statistical approach. and a sand sample with pure tar oil. The surfactant Classical crosscutting relationships or stratigraphic order will significantly enhanced PAH desorption and inhibited always be the ground truth measure of accuracy and proper microbial degradation by forming micelles that entrap PAH interpretation despite the level of precision reached in 2020. molecules, making them unavailable to microorganisms. The In addition to volcanology studies vastly improved spatial PAH aqueous phase concentrations in the batch experiments resolution at high precision will be the norm thereby were comparable to those obtained in the field experiment. increasing the utility of in situ analyses. Unfortunately, in Therefore, we conclude that the surfactant seems to be many cases argon concentration profiles occur at a spatial inevitable for the success of the remediation. As a resolution that will continue to confound our best current consequence, in order to describe the transport of desorbed instrumentation. Despite the fact that new ultra sensitive, ultra PAHs, micelles should be considered instead of single PAH clean multicollector mass spectrometers have jumped our molecules. science surprisingly forward, another leap will be required to achieve what every thermochronologist desires – an accurate [1] Lima et al (2012) Electrochim. Acta 86, 142-147. concentration profile at a geologically relevant length scale. Lastly, the seemingly straightforward task to get geochronology labs intercalibrated remains a perplexing obstacle that inhibits productivity and causes unnecessary confusion. Because calibration and operation of the new and highly stable multicollector instruments will soon become routine, we as a community can have every expectation that this nagging issue will soon be a topic of the past.

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234U/238U in speleothems revisited: Hidden hotspot track beneath Are there generally applicable Eastern United States relationships of this proxy to past DON HELMBERGER, RISHENG CHU, WEI LENG AND environmental change? MICHAEL GURNIS Seismological Laboratory, California Institute of Technology, JOHN HELLSTROM Pasadena, CA 91125 USA School of Earth Sciences, The University of Melbourne, Australia More than two thirds of surface hotspots associated with

234 238 234 238 volcanism can be explained by the interaction between a The initial activity ratio of U to U, ( U/ U)i, is the 1 234 238 moving plate and deep-seated mantle plumes . Most of these ratio of U to U atoms at time of formation of a sample, hotspot tracks are observed on oceanic or thin continental relative to that at secular equilibrium. It is found using their lithosphere. Although there are not many traditional hotspot measured present ratio and the known age of a sample, and is tracks on old continents, there are diamondiferous kimberlites a by-product of all U-Th disequilibrium dating as well as some indicative of deep mantle origins2. This poses the question that U-Pb dating of Quaternary samples. As such there is now an there could be many more hotspot tracks beneath old enormous body of these data in the published literature. A continental regions than suggested by the record of surface number of publications have addressed paleoenvironmental 234 238 volcanism. Here we show that seismic waveforms recorded by significance of ( U/ U)i over the last few decades but no USArray from a recent Virginia earthquake reveal an clear consensus has emerged, other than that this initial unexpected linear, lower lithosphere seismic anomaly disequilibrium is caused by some combination of alpha recoil 234 extending from Missouri to Virginia without a clear and selective dissolution of U as seepage water makes its relationship to surface geology. This east-west corridor has P way to the cave, and that hydrological factors probably have velocity reduced by 2.1% along with high attenuation and the greatest influence. General observations are that 234 238 crosscuts prominent regional features suggesting a link to ( U/ U)i tends to gradually fall with time at a given plate motions. We suggest that a thermal plume-like upwelling location, often to values well below one in relatively old, interacting with the base of the continental lithosphere can stable settings, and that significant paleoenvironmental produce the requisite seismic signal. A Late Cretaceous changes invariably lead to some form of change superimposed kimberlite in Kentucky, dated 75 Ma, pins a hotspot track that upon this. The nature of these latter changes remains poorly 234 238 bends northward beneath Virginia. Seismic data indicates that understood. They vary hugely in magnitude with ( U/ U)i the lower lithospheric anomaly along this northeastern values as high as 10 and as low as 0.5 having been observed, segment is even stronger than the east-west segment, and are sometimes highly responsive to reconstructed external supporting such a hypothesis. environmental change and sometimes lagged by thousands of years. Here I will report progress in understanding of the 234 238 hydrological significance of ( U/ U)i in speleothems, and of its significance for paleoenvironmental reconstruction and also for dating using the U-U and U-Pb techniques

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Pre-nucleation clustering of noble Dolomite reaction rim growth under metals in high-temperature magmatic non-isostatic stress liquids V. HELPA1*, E. RYBACKI1, G. DRESEN1, W. HEINRICH1, 2 1 1 2 2 R. ABART , L. MORALES H. M. HELMY *, C. BALLHAUS , R. O. C. FONSECA , R. WIRTH3, T. NAGEL2, M. TREDOUX4 1GFZ Potsdam, Telegrafenberg, 14473 Potsdam, Germany 1 (*correspondence: [email protected]) Minia University, Minia, Egypt (correspondence. 2University of Vienna, Althansstrasse, 1090 Vienna, Austria [email protected] 2 Steinmann Institute, University of Bonn, Bonn, Germany Reaction rims of dolomite (CaMg[CO ] ) were produced ([email protected]) 3 2 by solid-state reactions of oriented calcite (CaCO ) and 3GFZ Potsdam, Germany ([email protected]) 3 4 magnesite (MgCO ) single crystals using a gas-deformation University of the Free Sate, Bloemfontein, South Africa 3 apparatus at 400 MPa confining pressure, 750 °C, and run ([email protected]) durations ranging from 4 to 76 h. In addition, we applied a differential stress up to 40 MPa perpendicular to the contact The conventional view is that magmatic trace minerals interface. nucleate and grow by assembling cationic and anionic species The resulting dolomite reaction rims consist of two from the melt. Experiments reported here suggest that this different textural domains. Granular dolomite grains (2.2–5 view may be simplistic. We have investigated on the µm grain size) grew next to calcite, while elongated palisade- nanometer-scale the distribution of Pt in Fe-Cu-S sulfide shaped grains (2.2-5.2 µm diameter) grew perpendicular to the matrix. When ligands like arsenic are added to the sulfide, Pt magnesite interface. The thickness of the granular dolomite and As self-organize to Pt-As molecules, non-crystalline (Pt- layer is 2.9-11.2 µm, smaller than the palisade-like layer (5.2 As) clusters, PtAs nanoparticles, and at very high n 2 to 13.2 µm). Platinum markers show that the initial interface is temperature to nanometer-sized droplets of Pt-rich Fe-As melt. located between granular and palisade-forming dolomite, With the addition of As, the partitioning of Pt among sulfide indicating that rim growth occurred by counter diffusion of phases is shifted relative to simple (As-free) systems by at MgO and CaO. least an order of magnitude. Similar to minerals crystallizing As expected, rim thickness increased with increasing run from aqueous solutions, magmatic trace minerals may grow by duration. The effect of the applied load is not systematic and oriented attachment of nanoparticles and nanophases when causes a maximum variation in rim thickness of less than 11% they crystallize from magmatic solutions. This explains how at fixed time. noble trace elements could form discrete mineral phases in Diffusion of MgO across the dolomite reaction rim into subsolidus range although their concentrations in magmatic calcite produced newly formed magnesio-calcite grains with melts do not exceed tens of ppb to few ppm. Pre-nucleation an average diameter of 20.7 to 34.8 µm. Grain size of clustering should be considered when highly siderophile magnesio-calcite grains increased with increasing distance to elements (HSE) partition coefficients determined by simple the dolomite boundary. The magnesio-calcite layer increased system experimentation are used to model HSE fractionations from 29.1 to 63.3 µm with time, but was also not affected by among chemically more diverse reservoirs of the Earth the differential stress conditions.

The experiments indicate that differential stresses up to 40 [1] Tredoux et al (1995). South African Journal Geol 98, 157– MPa do not significantly change the kinetics of reaction rim 167. growth in the carbonate system. Possibly this is because

volume diffusion is the dominant transport mechanism, which presumably is less strongly affected by deformation than grain boundary diffusion.

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Picking apart paleoredox proxies: Rare Earth Element distributions as What regulates them? tracers of micronutrient input and GEORGE R. HELZ*1 Nd cycling in the South Atlantic 1Department of Chemistry, University of Maryland, College DEBORAH J. HEMBURY*, XINYUAN ZHENG, Park, MD 20742 USA (*correspondence: [email protected]) PHILIP HOLDSHIP, PETER SCOTT, MATTHEW POINTING, AND GIDEON M. HENDERSON Certain trace elements that are oxyanions (broadly Department of Earth Sciences, University of Oxford, South defined) with long seawater mean residence times (e.g. Parks Road, OX1 3AN, UK (*correspondence: HVO 2-, CrO 2 AsO 3-, MoO 2-, Sb(OH) -, WO 2-, ReO 2-, and 4 4 4 4 6 4 4 [email protected]) 2- ! UO2(CO3)2 ) are modestly to strongly enriched relative to Earth’s crust in sediments below O -depleted waters. Their 2 Concentrations of the REEs in seawater reflect their inputs enrichment in sedimentary rocks is cited to support qualitative and their cycling in the water column. Because the behaviour conclusions about redox conditions in ancient sedimentary of the REE have some similarities to that of micronutrient basins. More nuanced, possibly quantitative conclusions elements (such as Fe, Zn, Cu, Cd) but are not directly require better knowledge of events that regulate conversion of biologically utilised, their distribution has potential to these particle-inert oxyanions to particle-reactive species. constrain the cycling of micronutrients. The cycling of Nd is Each of these elements exists in multiple oxidation states in also of particular interest because Nd isotopes are widely used nature, inviting the assumption that pE regulates conversions. as tracers of past ocean circulation. In this study, we have But pE is indefinable in natural waters, so this is at best a measured REE concentrations on filtered samples collected superficial explanation. In some cases, abiotic or biotically during the UK-GEOTRACES GA10 cruises (D357, JC068) mediated electron transfer, leading to insoluble products, is o across the South Atlantic at 40 S. CTD profiles and a full indeed a regulating mechanism (U the most studied example). range of other chemical parameters provide a comprehensive In other cases (e.g. Re), evidence for an electron transfer context for these new REE measurements. REE samples were mechanism is lacking. In sulfidic solutions, most of these obtained for the full- water column and concentrations oxyanions undergo O & S exchange. If the particle reactivity determined by isotope-dilution MC-ICP-MS on 250 ml of the thioanions exceeds that of the oxyanions, then O & S samples. This samples all the major deep-water masses of the exchange could be a deposition-regulating mechanism. Often Atlantic, and a clear water-mass dependence is observed in the exchanges are labile, probably abiotically and thermodynam- concentrations of heavy REEs. The light REEs show ically controlled, and thus invariant over geologic time. significantly less water-mass dependence, however, Important gaps remain in knowledge of what regulates de- suggesting the importance of downward particulate transport position of these elements--for example, polysulfides’ role. for their cycling, with implications for the interpretation of Nd Recent evidence demonstrates polysulfides’ importance, at isotopes. Ce concentrations demonstrate the lack of least for Mo and As. Another gap concerns organic matter’s significant input in intermediate waters, reflecting O levels role. Correlations between the above elements and TOC are 2 that are insufficiently depleted to drive Mn cycling in the well known in sediments beneath O -depleted waters. 2 sediment, but are notably high in surface waters due to Correlations might be incidental or might point to specific additional inputs and active release from particles. biotic or abiotic organic reactions that participate in trace element deposition mechanisms. Good evidence exists for organic hosting of V and Re in TOC-rich sediments, but this may arise after deposition, during early diagenesis.

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The K/Ar system for tracing fine- The Central Indian Upper Mantle grained terrigenous sediments: 50 MY ago: Continental crust versus A survey of Atlantic clay fractions oceanic crust recycling contributions SIDNEY R. HEMMING1,2*, PIERRE E. BISCAYE2, within the Central Indian Basin RAHUL SAHAJPAL3, JENNIFER M. COLE2,4 MORB AND WALLACE S. BROECKER1,2 1 1 1 2, 1 C.HEMOND , H. DELAVAULT , M. JANIN , P. DAS AND Department of Earth & Environmental Sciences, Columbia 2 S. IYER Univ. [email protected] (* presenting author) 2Lamont-Doherty Earth Observatory of Columbia University 1UMR Domaines Océaniques, Univ. Brest – CNRS, Plouzané, 3School of Earth and Environmental Scinces, Queens College. France. ([email protected]) 4Western Kentucky Univ., Dept. of Geography & Geology 2National Institute of Oceanography, Dona Paula, Goa, India

The provenance of terrigenous sediments provides The central Indian Ocean Basin (CIOB) results from the important constraints on the processes that bring them to their activity of both the Central and Southeast Indian Ridges and depositional sites in the ocean. Terrigenous sediments are carries also the tracks of the Rodrigues triple junction and the formed by weathering and are delivered to the ocean by wind, Reunion Hotspot 53 Ma ago. water, and ice, and are redistributed within the ocean by We discuss the composition of the Indian upper mantle 50 currents. The mineralogical content and geochemical Ma ago i.e. its level of isotope heterogeneities within a model composition of sediments reflect the source rock types, in which the breakup of the Gondwana has introduced weathering style and intensity, as well as sedimentary sorting continental derived material in it. The potential input of evidence for sedimentary transport and delivery mechanisms. Reunion hotspot derived material is also investigated. Radiogenic isotopes provide a measure of the temporal All samples dredged in an area comprised between 72- ! ! geologic history of sediments that is different depending on 80 E and 9-15 S. They are on axis MORBor off axis MORB the geochemical characteristics of the parent and daughter seamounts and are tholeiitic in composition and slightly isotopes. The K/Ar system in fine-grained terrigenous depleted in incompatible trace elements. sediments reflects the latest stages of the geologic history of Isotopes (Sr,Nd, Hf and Pb) lead to class samples in four the sediments’ sources. Thus the K/Ar “age” of fine-grained groups: 1) very depleted in Sr-Nd and Hf isotopes including sediments provides a useful measure of sediment provenance, amongst the least radiogenic Pb isotope sof the Indian previously demonstrated by several studies (e.g., Hurley et al, MORBs regarded as the depleted Indian MORB mantle 50Ma 1961, GSAB, 1963a, GCA, 1963b, GCA; Jantshik and Huon, ago. 2 and 3) Similar low 206Pb for higher 208Pb and intend to 1992, Eclogae Geol. Helv.; Huon and Ruch, 1992, Mar. Geol.; have even lower 206Pb than the previous group but very Pettke et al, 2000, EPSL; Hemming et al, 2002, Chem. Geol.; radiogenic Sr and unradiogenic Nd or DUPALsignature. vanLaningham et al, 2006, JGR, 2008, QSR, 2009, EPSL; The last group has more radiogenic Pb isotopes, and slightly vanLaningham and Mark, 2011, GCA). lower Nd for identical Sr isotopes of the DMM group. This is An initial survey of the <2 µm fractions of samples from clearly regarded as representative of recycled oceanic crust the Biscaye (1965, GSAB) clay mineral study, demostrates material such as seen in Ocean Island Basalts (C, Fozo, that in contrast to the strong latitudinally-controlled HIMU). distribution of kaolinite/chlorite in Atlantic sediments, K/Ar Mixing models suggest three components and two stages model ages trend from oldest in the NW Atlantic to youngest of mixing to account for the results. The local DMM is first in the SW Atlantic. Intermediate ages are found in the tropical contaminated by African Lower Continental Crust (LCC) belt as well as off the coast of Europe. Though the data are material such as granulites during continental breakup. still sparse, the general trends are well matched to the known In conclusion, the very depleted local DM and the distribution of geologic ages of continental sources around the extreme DUPAL compositions support the concept of LCC Atlantic basin, with extreme old ages in Canada and contamination of the upper mantle during the Gondwana Greenland and extreme young ages in active tectonic settings breakup as 50Ma ago, the mixing and assimilation of the like the southern tip of South America and the Scotia Arc. LCC being less advanced than in today Indian upper mantle. This study will produce a map of sediment distribution This leads to more extreme resulting isotope composition than that serves as a benchmark to explore ocean circulation of today sediment transport questions over a variety of timescales.

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Evolution of photosynthesis The zinc isotopic composition of JAMES HEMP1, LAURA A. PACE 2 , JENA E. JOHNSON1 AND siliceous marine sponges: WOODWARD W. FISCHER1 Investigating nature’s sediment traps 1 California Institute of Technology ([email protected]) 12 23 KATHARINE R. HENDRY AND MORTEN B. ANDERSEN 2 University of Utah 1School of Earth and Ocean Sciences, Cardiff University, The evolution of chlorophyll-based phototrophy was one Main Building, Park Place, Cardiff, CF10 3AT, UK of the most important bioenergetic innovations in the history 2Department of Earth Sciences, University of Bristol, Wills of life on Earth, but key first-order questions about its Memorial Building, Queens Road, Bristol, BS8 1RJ, UK evolution remain. Here we present genomic and biochemical 3ETH Zürich, Inst. f. Geochimie und Petrologie, data that place new constraints on the acquisition of Clausiusstrasse 25, 8092 Zürich, Switzerland phototropy in different clades. There are currently six known phlya of bacteria that have chlorophototrophic members; The Zinc (Zn) content and isotopic composition of marine Cyanobacteria, Proteobacteria, Chloroflexi, Chlorobi, biogenic opal has the potential to yield information about the Firmicutes, and Acidobacteria. Cyanobacteria perform nutrient availability, utilisation and organic matter export from

oxygenic photosynthesis using H2O as an electron donor, surface to deep waters. Here, we report the first

generating O2 as a product. All of the other clades perform measurements of Zn isotope composition of deep-sea benthic anoxygenic photosynthesis using a variety of reduced sponge skeletal elements (spicules) from the Southern Ocean. compounds as electron donors. Despite these differences, all Our results highlight different Zn uptake and fractionation known chlorophototrophs share only three common molecular behaviour between the two major siliceous sponge clades elements; (bacterio-)chlorophyll, reaction centers, and (hexactinellids and demosponges), which is most likely linked quinol:electron acceptor oxiodoreductases (complex III). to sponge filter-feeding strategy and internal physiology. Chlorins can be classified into two types; chlorophylls and Hexactinellid spicule Zn isotopic compositions are not bacteriochlorophylls, with the latter only found in anoxygenic fractionated with respect to seawater, and so hold potential as phototrophs. Recent analyses of chlorin biosynthesis pathways proxies for past ocean Zn cycling. In contrast, demosponge provide support for the evolution of chlorophyll preceding that spicules exhibit a wide range of Zn isotopic compositions that of bactriochloropyll1. are related to the opal Zn concentration, most likely reflecting Reaction centers are proteins that convert light energy into fractionation processes during feeding. As such, demosponge high energy electrons. Two evolutionarily related types of Zn isotope records may be able to shed light on past changes reaction centers exist, RCI and RCII. Anoxygenic in photic zone organic matter formation in the ocean. phototrophys contain either RCI (Firmicutes, Chlorobi, and Acidobacteria) or RCII (Chloroflexi and Proteobacteria). In oxygenic photosynthesis RCI and RCII are coupled together in

series, which allows electrons to be transferred from H2O to ferredoxin. Evolutionary analysis of reaction centers show that their distribution reflects lateral gene transfer2. Complex III proteins convert high energy electrons into a protonmotive force. There are two evolutionarily unrelated

complex III’s—the b6f/bc1 superfamily and alternative complex III (ACIII). These enzymes are part of a high potential redox module that is shared with aerobic respiration and denitrification. The distribution and evolutionary relationships of complex III and the high potential module support the inferences from chlorin biosynthesis and reaction centers and demonstrates the remarkable conclusion that most currently known anoxygenic phototrophs acquired photosynthesis after the evolution of aerobic respiration, and therefore after the evolution of oxygenic photosynthesis.

[1] Bryant and Liu (2013) Adv. Bot. Res.,Volume 66. [2]. Raymond, et al (2002) Science 298:1616

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Effect of increased glacier melt on P-T evolution of Neoproterozoic and diagenetic Fe cycling in marine Ordovician metamorphic rocks in the sediments at King George Island Iberian Massif, Central Portugal (Antarctica) S.B.A HENRIQUES1*, M.L. RIBEIRO1, A.M.R. NEIVA2, 3 4 1 2 3 3 G.R. DUNNING AND L. TAJCMANOVA S. HENKEL *, S. KASTEN , H. SALA , A.S. BUSSO AND M. STAUBWASSER1 1LNEG, Dpt. of Geology, Ap.7586, Amadora, Portugal; 1 (*correspondence: [email protected]); Institute of Geology and Mineralogy, Uni. of Cologne, GER ([email protected]) *correspondence: [email protected] 2Earth Sciences Dpt. and Geosciences Centre, University of 2 Alfred Wegener Institute, Bremerhaven, GER 3 Coimbra, Portugal ([email protected]) Dirección Nacional del Antártico - Instituto Antártido 3Earth Sciences Dpt., Memorial University, St. John’s NL Argentino, Buenos Aires, ARG A1B 3X5 Canada ([email protected]) 4Department of Earth Sciences, ETHZ, Clausiusstrasse 25, The glacier melt of the Western Antarctic Peninsula and CH-8092, Zurich, Switzerland; its surrounding islands influences biogeochemical processes in ([email protected]) the water column and the marine sediment by changing the

flux of mineral particles and nutrients (e.g. Fe) into the ocean. The study area is located at the boundary of the Ossa Morena- Sediment and pore water samples were collected at King Central Iberian zones in the Iberian Massif. An island arc and a George Island (South Shetland Islands) to unravel how the continental margin setting were active during the Ediacaran vicinity of ice-covered and -uncovered terrestrial environment period. Both events are represented in the Sardoal Complex (SC) affects redox zonation and diagenetic processes in the coastal by amphibolites and felsic orthogneisses, respectively. An sediments. The post-depositional dissolution of Fe-minerals Ordovician rift magmatic event is recorded, in the Mouriscas and the stable Fe isotope signatures of pore water and specific Complex (MC), by a protomylonite trondhjemite and a garnet Fe minerals were of special interest since changing Fe supplies amphibolite with a MORB signature. We present the first P-T - as reactive particles via melting icebergs or meltwater diagrams based on the thermodynamic modelling, which were streams or dissolved via diffusion from the sediment into the computed using the Perple_X. The ID-TIMS U-Pb metamorphic bottom water - might not only impact local biogeochemical zircon age from the SC amphibolite is 539 ± 3 Ma. The estimated cycles but most likely also impact productivity in the Southern P-T conditions were based on the compositional isopleths for key Ocean. mineral phases in the stability field (Cpx-Am-Pl-Ilm-Ttn) at 7"8 Sediment cores of up to 45 cm length were retrieved in kb and 640-660º C. The ID-TIMS U-Pb metamorphic monazite Potter Cove, Marian Cove, and Maxwell Bay. In vicinity to age from the felsic orthogneiss is 539 ± 2 Ma. The P-T path the glaciers the sediments showed an extended redox zonation. 2+ indicates an evolution from 4.5 kb and 590º C in the Bt-Pl-Ms- The post-oxic zone with Fe concentrations of up to 300 µM Grt-Sil-Qtz-Rt-Ilm field towards lower pressure and temperature ranged from 1 to 25 cm depth. Most probably, microbial field Bt-Pl-Ms-Grt-Qtz-Ilm at 4-4.5 kb and 570-580º C. The ID- activity in sediments close to the glaciers is sluggish due to TIMS U-Pb igneous zircon age from MC protomylonite low input of organic matter (OM). More condensed redox trondhjemite is 483 ± 1.5 Ma. The estimated P-T conditions were zones prevailed in troughs where OM from terrestrial or based on the compositional isopleths for key mineral phases in the marine sources accumulates and in vicinity to research 2+ stability field (Bt-St-Pl-Ms-Grt-Sil-Qtz) at 4.5-6.2 kb and 590- stations. The upward directed diffusive Fe fluxes as inferred 650º C. The ID-TIMS U-Pb igneous zircon age from the MC from pore water profiles range between 0 and ~1050 µM m-2 -1 garnet amphibolite is 477 ± 2 Ma. The estimated P-T conditions d . However, the correlation to the intensity of diagenesis is were based on plagioclase and biotite isopleths in the stability not straightforward. Fe isotopes of specific minerals were used field (Bt-Chl-Ep-Am-Pl-Ilm-Mag-Grt-Qtz) at 6.5 kb and 550º C. to assess the intensity of Fe cycling. With ongoing Fe-oxide 56 Two major geodynamic events at the amphibolite facies dissolution, the residual Fe pool becomes enriched in Fe, conditions were identified in this study. The first one, the whereas dissolved Fe and secondary Fe-oxides become continental arc accretion of the Ossa Morena Zone to the Iberian enriched in 54Fe. Thus, easily reducible Fe oxides show lowest 56 Autochthon passive margin (Northern margin of Gondwana) ! Fe values at the top of the sediment column. We suggest occurs at ca. 540 Ma. The second one, younger than ca. 477 Ma is that the retreat of the glaciers indirectly results in higher OM probably connected to the opening of the Rheic ocean. fluxes to shelf areas fueling diagenetic processes/nutrient recycling.

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Parallel budgets of excess Element outgassing in BABB: and in grain-size An example from the Havre Trough separates of marine sediments from J.M. HERGT1* , J.D. WOODHEAD1, A. GREIG1, the North Atlantic over the past R.J. WYSCOCZANSKI2, M.I. LEYBOURNE3, E. TODD4 AND AND C. WRIGHT5 20,000 years 1School of Earth Sciences, The University of Melbourne, VIC, 1 1 LEONARD E. HENRY *AND JERRY F. MCMANUS 3010, Australia Lamont-Doherty Earth Observatory Of Columbia University, (*correspondence: [email protected]) 2NIWA, Private Bag 14901, Wellington, 6021, New Zealand Geochemistry Division, Palisades, Ny, 10964 Usa, 3 2 ALS Geochemistry, North Vancouver, BC Canada V7H 0A7 [email protected] (*Presenting Author) 4 [email protected] Alaska Science Centre, USGS, Anchorage, AK 99508-4626, USA 5 Abrupt shifts in the Atlantic’s circulation regime have National Oceanography Centre, Southampton, Empress Dock, been inferred from carbon isotopes within benthic European Way, Southampton SO14, 3ZH, UK foraminfera, geostrophic gradient shifts captured in oxygen istopes from benthic , changes in the burial ratio Trace element data have been acquired for glass rinds and of 231Pa/230Th in bulk sediment, and variations in sortable silts. corresponding whole-rock samples of back-arc basin basalts Drift deposits, those regions of the ocean where the energy of from the Havre Trough in the SW Pacific. For most elements currents slaken and sediment is deposited in excess of the the match in compositions between glass and whole-rock pairs local vertical particle flux, are often selected for 231Pa/230Th is essentially identical to within analytical uncertainties. In and other paleoceanographic reconstructions because the other cases, small variations exist that can be explained by the sedimentation rates far in excess of he mean ocean, thus lack of olivine (for example) phenocrysts in digests of the allowing for greater resolution of transient climate events than handpicked glass. in other seafloor sediment cores. Most of the fine sediment In contrast, volatile elements show more marked (<20micron) that constitutes a large fraction of mass within differences that we attribute to outgassing of the magmas these deposits is laterally transported. Previous work during vesiculation and eruption. Although most researchers suggested the fine fraction of the sediment carries a would agree that Cd is highly volatile, our observation is that disproportionately high concentration of excess 230Th, or Cd is only slightly enriched in the glass (glass averaging Cd 230 234 contents only ~7% higher than rock). In contrast, the largest Thxs, produced by the decay of U in sea water and scavenged by settling particles, and extra-terrestrial helium, discrepancies between the whole rock and glass compositions 3 are in W (enrichment factor of ~30) and Mo (enrichment HeET, two nuclides whose mass flux aids in the reconstruction of past climate events. While the results are consistent with factor of ~5), and these elements also show an excellent 230 correlation with each other. Given that these two elements are past findings for Thxs, we find a contrasting distribution of 231 broadly believed to be less volatile compared with Cd, the Paxs that serves as a cautionary tale towards assuming that a similar size-dependence applies to all particle-reactive most reasonable conclusion might be that the glass rinds lost elements. much of this highly volatile element prior to quenching. This study presents side-by-side size-fraction budgets of Similar comparisons have been made with other elements in 230 231 order to assess their relative volatilities in this back-arc basin Thxs and Paxs over the last deglacial from core CDH19 taken from a North Atlantic drift deposit, on the Bermuda setting. 231 Rise. Our results suggest that Paxs is more evenly 230 distributed among size-fractions than is Thxs, possibly 231 indicating that Paxs is less susceptible to the biasing effects of particle focusing and more sensitive to the drivers of vertical particle flux. Further, 230Th normalized fluxes of the size-fraction separates imply that the maximum changes in the 231 230 Paxs/ Thxs ratio that occurs across 1 are evenly distributed across all size fractions.

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Exhumation rates from orogenic Experimental constraints on carbon areas recycling in subducted sediments and FREDERIC HERMAN1, JEAN-DANIEL CHAMPAGNAC2, altered oceanic crust 2 2 MARTEEN LUPKER AND SEAN D. WILLETT 1 1,2 JÖRG HERMANN AND LAURE MARTIN 1 Institute of Earth Sciences, University of Lausanne, 1 Reasearch School of Earth Sciences, The Australian National ([email protected]) University, ACT Australia. [email protected] 2Department of Earth Sciences, ETH 2 Centre for Microscopy, Characterisation and Analysis,

UWA, 35 Stirling Highway, Crawley WA6009 Asutralia. A critical issue in the global mass balance of sediment is assessment of the importance of the rates and links between Altered oceanic crust and sediments are the main host physical erosion and chemical weathering in tectonically rocks within the subducted lithosphere to transport carbon active, high relief regions. There are two issues in these from the Earth’s surface to the mantle. Whether carbon is regions. First is determining the physical erosion rates in these effectively recycled toward the atmosphere through arc areas which is problematic given the high variance in magmatism located above subduction zones, or buried into the measured erosion rates, low concentrations and high errors in deep mantle, remains controversial. cosmogenic ages and young thermochronometric ages. The We have conducted experiments in a carbonate-bearing second problem is in generalizing erosion laws calibrated to metapelite and in altered oceanic crust at 2.5-4.5 GPa and 700- low relief areas to these high relief areas. For example, erosion 1000°C, i.e. under conditions relevant for subducted slabs at laws based on linear or non-linear diffusion of hillslopes sub arc depth. The experiments contained 2-7 wt% H O, saturate at high erosion rates and high slope and have no 2 simulating interaction of the rocks with an externally derived predictive capability. We address each of these problems aqueous fluid. The wet solidus in both rock types is very through a detailed analysis of a new global compilation of similar and occurs at ~700°C at 2.5 GPa and at 800-850°C at more than 17,000 low-temperature thermochronometric ages. 4.5 GPa. At subsolidus conditions residual carbonates are Here we focus on erosion rates and topographic characteristics common and they coexist with hydrous phases such as of the highest relief regions of the active orogenic regions of phengit, epidote and lawsonite. We have developed a new the world. We compare erosion rates to common geomorphic method to determine the proportion of CO in the fluid, where metrics including mean slope and relief on different scale. We 2 the experimental capsules are pierced under vacuum and the find no statistically significant relationship between relief or gas is directly analysed with a gas chromatograph. We show slope and erosion rate. Our result is consistent with theory that that the molar proportion of CO in the aqueous fluid in predicts that hillslopes reach a maximum value at which there 2 altered oceanic crust decreases with increasing pressure from is no relationship between slope and erosion rate. Our results 0.06 to 0.03 and thus 70-90% of the original carbonate are demonstrate the difficulty in generalizing or predicting erosion retained in the rocks. Above the solidus at pressures .3.5 GPa rates in high-relief areas that lack direct measurement and hydrous silicate melts coexists with carbonates and less then contrasting these values to low-uplift regions where physical 25% of the original carbonate is dissolved in the melt. The processes and governing equations differ. carbonate solubility in hydrous silicate melts increases with

increasing pressure. Additionally, at 4-4.5 GPa, T/850°C globules of Fe-Ca-rich carbonate-quench occur in the hydrous silicate melt in altered oceanic crust and in sedimets, indicating that immiscible silicate and carbonate melts

coexists. These carbonate melts contain SiO2, Al2O3 and P2O5

and TiO2 at a wt.% level and high amounts of U and Th. There are only accessory amounts of residual carbonate at these conditions and 90-100% of the original carbonate is removed from the protholith. Our results suggest that fluid fluxed partial melting of altered basalts and sediments provides an efficient mechanism by which significant amounts of subducted carbon can be brought back to the atmosphere via arc magmatism on relatively short time scales of less than 10 Ma.

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Mineral-fluid interactions and time- Calcification rate and carbon-isotope integrated fluxes in tin-bearing fractionation in coccolithophore greisens, Kru#né hory (Erzgebirge) calcite through laboratory culture Mts., Central Europe experiments MATYLDA HE0MANSKÁ1 AND DAVID DOLEJ11 M. HERMOSO1,*, F. MINOLETTI2, Y. CANDELIER2, 1 3 1 1 H. MCCLELLAND , G. ALOISI AND R.E.M. RICKABY Institute of Petrology and Structural geology, Charles University, 128 43 Praha 2, Czech Republic 1 University of Oxford, Dept. Earth Sciences, Oxford, UK, [email protected] (* presenting author). Hydrothermal fluids are major mass transport agents in the 2 Univ. Paris 06 and 7193, Paris, France. lithosphere and reactive fluid flow underlies alteration and 3 Univ. Paris 06 and 7159, Paris, France. ore-forming mechanisms in diverse settings. In contrast to our advanced knowledge of alteration mineralogy and The physiology of marine calcifiers such as haptophytes geochemistry, little is known about the volume of fluids substantially affects the fractionation of carbon isotopes into responsible for specific mineralization or about the nature of biominerals. The resultant offset from equilibrium replacement, i.e. dissolution-precipitation reactions on the fractionation is often referred to as the "vital effect". The microscale. We use alteration zoning of cassiterite-bearing geological record of climate and the composition of seawater greisens from the Kru2né hory (Erzgebirge) Mts. in Central reconstructed from sedimentary biominerals is therefore not Europe as model example to interpret the fluid-mineral completely faithful. The aim of this work is to examine and reaction mechanisms and calculate the time-integrated fluid quantify this biologically-induced distortion of the carbon fluxes. The greisen veins and swarms are hosted by highly in coccoliths in order to develop a evolved Li-F-P-rich biotite and zinnwaldite granites with mechanistic understanding of the vital effect in the

topaz and tourmaline. Magmatic plagioclase (An<10) and K- coccolithophores, determine species-specific fractionation

feldspar (Or>84Ab<16) exchanged Na and K prior to factors to derive the actual composition of seawater, and greisenization. Dark micas are represented by lithian annite eventually be able to reconstruct climates more reliably using continuosly evolving to zinnwaldite, whereas white mica species separation techniques for fossil coccoliths. corresponds to lithian Fe-bearing muscovite. Greisenization Calcifying strains of haptophytes were subjected to a occurs in several stages: (i) breakdown of feldspars to quartz series of perturbation experiments in the laboratory in order to and sericite or muscovite. Silicification and muscovite determine the effect of changes in the physico-chemical formation are spatially decoupled and represent dissolution- composition of the ambient environment (temperature, DIC precipitation process, which requires local transport of Al, (ii) level, pH, calcium concentration and phosphate concentration) replacement of dark mica by celadonitic muscovite under on that of the biominerals and the organic matter. For all these volume-conserved conditions. This reaction requires experiments and for all the species, the partitioning of carbon significant Al addition and Mg, Fe release, (iii) breakdown of into photosynthetic versus calcification pathways seems to be muscovite to topaz and quartz. This is a dissolution- the primary driver of differences in the carbon isotopic precipitation reaction under Al-conserved conditions but composition of coccoliths. A second-order but still important declining fugacity of HF, and (iv) hydraulic fracturing and parameter to consider for interpreting carbon isotopes is the open-space filling by quartz greisens and monomineralic active mechanisms used by the cells to concentrate carbon

veins. Thermodynamic simulation of fluid-mineral interaction (CO2) within the chloroplast and the coccolith vesicle. during disequilibrium infiltration in a pressure-temperature Empirically revealed through pH and TDIC perturbation gradient reveals that the formation of mica-quartz and topaz- experiments, variations in CCM efficiency can lead to 4‰ quartz greisens requires time-integrated fluid fluxes 102 to 103 offsets between species. Finally, frequent malformations of m3 fluid per m2 rock, and the corresponding fluid flow rate of coccoliths are observed for specimens grown under carbon 10-10 to 10-8 m s-1. The formation of a single greisen vein with limited conditions, or when cells reach their physiological a typical volume of 103–5·104 m3 would thus require 105–3·107 maximum division rate. m3 aqueous fluid that must have exsolved from an intrusion measuring 80-700 m in each dimension. This approach illustrates use of reaction stoichiometries and non-equilibrium transport theory in estimating fluid fluxes in hydrothermal ore- forming processes.

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Hydrogeochemical and isotopic Effect of trace metals and light signatures of Carboneras-Palomares intensity on biomarker isotopic Fault Area aquifers (SE Spain) fractionation P. HERNANDEZ-PUENTES1, R. JIMENEZ-ESPINOSA1* AND M.T. HERNÁNDEZ-SÁNCHEZ1,2*, H. STOLL1, J. JIMENEZ-MILLAN1 A. PIOTROWSKI3, A. MILNE4, M. LOHAN4 2 1 AND R. PANCOST Department of Geology and CEACTierra, Associated Unit IACT (CSIC-UGR), Faculty of Experimental Science, 1Geology Department, Univ. Oviedo, Oviedo, Spain. University of Jaén, Campus Las Lagunillas s/n, 23071 (*correspondance: [email protected]) Jaén, Spain ([email protected]; *correspondence: 2 Organic Geochemistry Unit, Univ. Bristol, Bristol, UK. [email protected]; [email protected]) 3 Department of Earth Sciences, Univ. Cambridge, Cambridge, UK Groundwater from Palomares-Carboneras Active Fault 4 School of Geography, Univ. Plymouth, Plymouth, UK. Area has been studied using geochemical (major ions) and 18 2 isotopic (data ' O and ' H). The study area is located in the Photosynthetic carbon isotope fractionation (*p) is mainly

eastern of Betic Cordillera (SE Spain). Hydrological changes controlled by CO2 concentrations, but also other factors such that follow major earthquakes has been investigated and found as nutrient availability, carbon uptake or cell size; thus, it can to be dependent on the style of faulting [1]. We try to establish provide insights into the marine carbon cycle. Most relevant a circulation model of groundwater and to identify the sources for paleoclimate and despite its high dependence on algal

of fluids from aquifers and the influence of water flow on the growth rates, alkenone *p has been invoked as a robust proxy

nucleation of new earthquakes. for reconstructing ancient pCO2 [1]. pCO2 reconstructions rely

Chemical composition of the waters reflects different on measured *p and a b coefficient (which integrates types and degrees of water–rock interaction and several physiological factors affecting isotope fractionation) which is geochemical families have been found: generally assumed to be constant (or corrected for cell size) (i) Na-Ca-Mg-SO4-Cl and Na-Mg-Cl-SO4 waters: over time at a given location. Previously, the wide variations

extreme EC (4000-14000 %S/cm): related to Pliocene marine in b coefficient of suspended particulate matter alkenone *p in marls in Vera Depression and Pulpí Corridor. ii) Na-Ca-Mg- the modern ocean was shown to correlate with seawater SO4-Cl and Na-Mg-HCO3-Cl-SO4 waters: high EC (2000- phosphate concentrations but in fact hypothesized to arise due 3500 %S/cm): related to dissolution of evaporites and to trace metal regulation of growth rate [2]. carbonates along deep faults. (iii) Ca-Mg-Na-HCO3-SO4 We further explore the effect of trace metal and light

waters: low EC (300-1000 %S/cm): in relation to dissolution of intensities on *p of different phytoplankton biomarkers carbonates from Sierra Cabrera, Sierra de Filabres and Sierra (including alkenones) for a smaller dataset in the modern

de Almenara. ocean. *p is positively correlated with light intensities that The '18O / ' 2H diagram indicates that the distribution of vary with collection depth, a trend which cannot be explained the samples define a local meteoric line less steep than the by lower growth rates at lower light but is consistent with World Online rainwater. The samples are better suited to the prediction of light limitation of carbon concentrating

meteoric water line of the Mediterranean, indicating that mechanisms. *p is inversely correlated with trace metals (Co precipitation of Mediterranean origin must contribute and Co+Zn), a correlation that is stronger than that bore with

significantly to the recharge area. However, a mixed origin, CO2 concentrations. Although further research is needed, our Mediterranean and Atlantic rainfalls, could be taken into observations suggest that trace metals and light intensity affect account. Samples from Sierra Cabrera and Fuente Alamo the b coefficient, and that variations in the b coefficient at a springs are more isotopically depleted. While Cuatro Caños given site must be accounted for in calibrations to reconstruct

and La Zanjilla springs appear more isotopically enriched. The ancient pCO2 accurately. prevalence of more negative values of 18O is associated with a greater height in recharge, regarding the two groundwater [1] Pagani et al (2002). Paleoceanogr. 17, 1069. [2] Bidigare samples from the northern area. et al (1997). Global Biogeochem. Cycles 11, 279-292.

[1] Muir-Wood and King, 1993. J. Geophysical Research 98- B12 (22035-22068)

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The fate of iodine-129 released from Spectroscopy and magnetic imaging the Fukushima-Daiichi nuclear at the nanoscale for the study of accident magnetic minerals MATT N. HEROD1*, MARTIN SUCHY2, IAN D. CLARK1, JULIA HERRERO-ALBILLOS123 3 2 W.E. KIESER AND GWYN GRAHAM 1 ARAID researcher at Centro Universitario de la Defensa. 11University of Ottawa, Department of Earth Sciences, Ottawa, Ctra. de Huesca s/n. 50090 Zaragoza, SPAIN ON, Canada, ([email protected]) 2ICMA (Universidad de Zaragoza - CSIC). Facultad de 2Environment Canada, Vancouver, BC, Canada Ciencias 50009 Zaragoza, SPAIN 3University of Ottawa, Department of Physics, Ottawa, ON, [email protected] Canada X-ray magnetic circular dichroism (XMCD) is the The Fukushima-Daiichi nuclear accident (FDNA) released preferential absorption of X-rays by a magnetic sample for left large amounts of fission product radionuclides into the and right circular polarized light. XMCD is produced at the environment in the spring and summer of 2011. Along with resonance absorption energies of the different atoms, and short lived fission products, iodine-129 (15.7 million year therefore provides element-specific magnetic information. half-life) was also released. 129I is recognized as a useful tracer Since its discovery in 1987 by Schütz, XMCD has been due to its mobile geochemical behaviour. To test if 129I pivotal in the understanding of magnetic materials and it is released by the FDNA was reaching Canada, rain samples nowadays routinely used in both basic and applied research in were collected in Vancouver from 2011 to March 2012. magnetism. X-rays with variable polarization at a wide range Archived precipitation samples from Environment Canada’s of energies are readily produced in nearly 50 synchrotron station on Saturna Island and from the National Atmospheric radiation facilities around the word, offering varied sample Deposition Program in northern Washington State were also environments (temperatures, pressure, magnetic fields, etc.) measured to establish a pre-accident 129I background. and XMCD-related techniques. Groundwater from the Abbotsford-Sumas Aquifer was One of the most exciting of those techniques is X-ray sampled to determine the fate of 129I. The mean pre-accident Photo-Emission Electron Microscopy (XPEEM). Using background for 129I in rain is 38.15 x 106 atoms/L (n=4). XMCD as a contrasts mechanism, in combination with a Immediately following the FDNA, 129I values increased spatial resolution down to 30 nm, element-specific spatially sharply to 227.2 x 106 atoms/L and quickly returned to near- resolved magnetization maps can be obtained. Moreover, background levels. However, pulses of elevated 129I continued recent developments in dedicated instruments, allow for several months. The 129I in shallow (3H/3He age <1.4 yrs) performing experiments at low temperatures (40 to 600 K), [1] groundwater were unchanged through November 2012 under applied magnetic fields (up to about 100 mT) and with with an average of 11.39 x 106 atoms/L (n=21). The 6-fold electrical contacts, as well as time resolved experiments (in increase in 129I concentrations from both Vancouver and the nanosecond range) to study magnetization dynamics. Saturna Island are coincident, and occur directly after the In this talk I will present the capabilities of those two initial release from the FDNA. This indicates atmospheric techniques in the study of the fundamental properties of transport and deposition of 129I and agrees well with the timing natural magnetic rocks and how a deep understanding of their of elevated 131I and 137Cs measurements in the United States nanostructure can shed light onto their macroscopic magnetic [2]. The lack of groundwater response suggests that 129I is properties. possibly attenuated in soil, which is consistent with its geochemical behaviour.

[1] Wassenaar et al (2006) Environ. Sci. Tech.40, 4626-4632. [2] Wetherbee et al (2012) Environ. Sci. Tech.46, 2574-2582 I (Arb. Units)

Co Ba 775 770 775 780 785 E (eV) Figure 1. Capabilities of XPEEM: Chemical map and related spectra where the distribution of Co and Ba on a sample is observed (left). Magnetization map on a Fe film, with two magnetic domains (right).

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Submicrometer exsolution lamellae in Molybdenum and uranium isotope volcanic as indicators of dynamics in a Paleozoic magma residence times epicontinental black shale 1,2 2 1 3 J HERRIN *, F COSTA , Y.Y TAY , H LIU ACHIM D. HERRMANN1, THOMAS ALGEO2, STEPHEN 1 AND S PRAMANA ROMANIELLO3, GWYNETH W. GORDON3 34 1 AND ARIEL D. ANBAR Facility for Analysis, Characterization, Testing, and Simulation, Nanyang Technological University, 1Coastal Studies Institute and Department of Geology and Singapore. (correspondence: [email protected]) Geophysics, Louisiana State University, Louisiana, USA 2Earth Observatory of Singapore, Nanyang Technological 2Department of Geology, University of Cincinnati, Cincinnati, University, Singapore. Ohio, USA 3School of Materials Science & Engineering, Nanyang 3School of Earth and Space Exploration, Arizona State Technological University, Singapore. University, Arizona, USA 4Department of Chemistry & Biochemistry, Arizona State Pyroxene geothermometry is a well-established tool for University, Arizona, USA the determination of thermal conditions of magmatic systems. Such applications are based largely on the presence of solvus Reconstructing the history of global ocean anoxia during relations within the pyroxene group that govern shifts in the Neoproterozoic and the Paleozoic is challenging since equilibrium composition as a function of temperature. These plate tectonic activity has destroyed the majority of the deep same solvus constraints can result in the subsolidus formation ocean floor from those time periods. In recent years, Mo and

of exsolution lamellae in pyroxene. Many natural examples U isotopes have been used as a proxy to track global O2 levels. exist in plutonic pyroxenes. Since coarsening of these lamellae However, these studies generally have to rely on the is largely a diffusion-moderated process [1], examination of sedimentary record of shallow epicontinental seas. Here we their size and spacing can potentially be exploited to obtain present Mo and U isotope variations of a Paleozoic black shale timescales or cooling histories of magmatic systems, provided (Hushpuckney Shale) from three different cores from across that empirical calibrations of controlling parameters (e.g. the same depositional basin to test whether global marine activation energies) are available. Volcanic systems present a redox conditions can be determined reliably from a single unique challenge for this application because the pyroxene section within an epicontinental settings. lamellae that they contain are typically nm-scale, owing to We find that, based on Mo and U enrichment factors (EF) rapid cooling, and are also highly localized. Here we report and nitrogen isotopes, three different intervals within the black the results of a chemical and crystallographic study of three shale can be distinguished. These intervals are characterized suites of rhyodacitic samples. To locate, image, and analyze by strong spatial and temporal geochemical gradients that multiple exsolution lamellae of tens to hundreds of nm in size indicate that the basin experienced non uniform environmental within clinopyroxene phenocrysts, we used a combined conditions along the black shale horizon. These gradients are approach consisting of initial characterization by reflected in systematic offsets of U isotopes across the basin SEM/EPMA/EBSD, targeted FIB sampling, and detailed by up to 0.5‰. Furthermore, during the transition to the most imaging and analysis by TEM/ATEM/SAED/EELS. Coupling reducing conditions (based on several geochemical proxies), these results with laboratory-calibrated models of lamellae the U isotopes attain their heaviest values while Mo isotopes formation and various end-member thermal cooling models of attain their lightest values. This indicates that local redox magma reservoirs [2] allows us to propose that these conditions can lead to anomolous isotopic signatures as rhyodacites, erupted decades apart, originated from a common current understanding of these isotope systems suggests that long-lived (several thousands of years) and relatively large both Mo and U should track each other during that transition. (tens of km3) magma reservoir. The study of exsolution These results suggest that chemical gradients across an lamellae in volcanic pyroxenes should prove useful to epicontintenal basin can lead to local redox conditions that constrain the thermal histories and sizes of magma bodies have a strong effect on the Mo and isotopic signatures. This below active volcanoes, but analytical obstacles abound. One spatial heterogeneity potentially challenges our ability to

significant challenge is to obtain quantitative TEM-based accurately reconstruct the accumulation of O2 on Earth from chemical analysis (EDS and EELS) with sufficient precision only one section from such settings. for geothermometry.

[1] Weinbruch et al (2003) GCA 67, 5071-5082. [2] Costa et al (2008) RiMG 69, 545-594.

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Natural organic matter and our Variations of $17O in terrestrial rocks current capacity to depict molecular D. HERWARTZ1*, A. PACK1 AND D.P. KRYLOV2 dissimilarity in complex mixtures 1Universität Göttingen, Geowissenschaftliches Zentrum, Abteilung Isotopengeologie, Goldschmidtstraße 1, 37073 N. HERTKORN*, M. HARIR, PH. SAND CHMITT-KOPPLIN Göttingen. (*correspondence: [email protected]) Helmholtz Zentrum München, German Research Center for 2Institute of Precambrian Geology and Geochronology, Environmental Health, Research Unit Analytical Russian Academy of Science, Makarova 2, 199034, St Biogeochemistry, Ingolstaedter Landstrasse 1, D-85764 Petersburg, Russian Federation, Neuherberg, Germany. (*correspondence: ([email protected]) [email protected]) Large mass independent effects in $17O are well known Natural organic matter (NOM) is the most abundant for extraterrestrial and stratospheric substances. Small fraction of organic carbon on earth. NOM occurs in all variations in $17O are expected in terrestrial rocks and terrestrial ecosystems such as soils, sediments, freshwater and minerals due to variations in the triple isotope fractionation marine environments, in the atmosphere and, throughout the exponent [3]. In this contribution we demonstrate that high- universe, in the form of prebiotic organic matter synthesized precision measurements of $17O allow identification and by interstellar chemistry. NOM is an exceedingly complex quantification of the interaction between rocks and ancient mixture of organic compounds that collectively exhibits a meteoric water. nearly continuous distribution of properties (size-reactivity We have developed a technique to measure $17O in continuum). silicates with a precision of 5 ppm (1# SD), which is an order NOM incorporates the hugely disparate characteristics of of magnitude better than had been achieved previously. To abiotic and biotic complexity. While biotic complexity derives characterize the $17O composition of the Earth we have from a plethora of evolutionary tested molecules with a rich measured minerals from mantle xenoliths and a variety of three-dimensional structure designed to execute specific crustal rocks and minerals. Our sample set included peculiar functions, abiotic molecular complexity is rather governed by gneiss samples from Karelia, Russia with !18O = –25‰ [2]. “mathematical synthesis” which maximizes compositional Silicate samples do not plot on a single terrestrial diversity under given conditions of reaction partners, radiation fractionation line (TFL), as frequently assumed. This is and temperature. Molecular level NOM composition and explained by differences in triple isotope fractionation structure at first depend on system characteristics and exhibit exponent in high- and low-T fractionation processes as well as far more variance than anticipated from often rather uniform by interaction between reservoirs with different $17O. bulk parameters. Nevertheless, all NOM on earth is connected Rock assemblages that have interacted with water fall on in a boundless carbon cycle. well-defined arrays in the $17O vs. !‘18O space. These arrays Successful non-target molecular-level analyses of NOM can be utilized to reconstruct the original oxygen isotope attempts to characterize the entire molecular complement composition of both, the samples and the hydrous fluid. present in NOM by means of information-rich detection We apply our finding to reconstruct the composition of methods, like NMR spectroscopy (provides unsurpassed water from low-!18O rocks from Karelia (Russia) that likely insight into short-range molecular order) and FTICR mass interacted with glacial melt waters during a snowball Earth spectrometry (provides depiction of the compositional space event. with unsurpassed resolution). This presentation provides an overview how modern [1] Young et al (2002) GCA 66; [2] Krylov (2008) Doklady organic structural spectroscopy can reveal key characteristics Earth Sci. 419A. in composition and structure of various NOM. Examples will include secondary organic aerosols (SOA) as well as marine organic matter and NOM in organic chondrites.

[1] Hertkorn et al (2007) Anal. Bioanal. Chem., 389, 1311- 1327. [2] Battin et al (2009) Nature Geoscience, 2, 598-600. [3] Schmitt-Kopplin et al (2010) Anal. Chem., 82, 8017-8126. [4] Schmitt-Kopplin et al (2010) PNAS, 107, 2763-2768. [5] Hertkorn et al (2013) Biogeosciences, 10, 1583-1624.

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Petrological evidence for deep lower Calcium isotope fractionation in mantle melting vertebrates CLAUDE HERZBERG A. HEUSER1*, A. EISENHAUER 2, K. SCHOLZ-AHRENS3 AND J. SCHREZENMEIR Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ, U.S.A. 1Steinmann-Institut, Universität Bonn, Bonn, Germany ([email protected]) (*correspondence: [email protected]) 2GEOMAR, Helmholtz-Zentrum für Ozeanforschung Kiel, Olivine phenocrysts in picrites from Baffin Island and Germany West Greenland (BIWG) have elevated Ni contents consistent 3Max Rubner-Institut, Bundesforschungsinstitut für Ernährung with derivation from a Ni-rich peridotite source [1]. und Lebensmittel, Kiel, Germany Interaction of a silicate melt with the core may have provided the excess Ni [1]. Partial melting is consistent with Earlier investigations showed that there is considerable experimental results on the solidus of peridotite near the core- biological fractionation of Ca isotopes in vertebrates. mantle boundary [2]. Ni/Co in BIWG lavas and olivine Consequently it was suggested that Ca isotope fractionation phenocryst are also higher than those in MORB, consistent may be applied as a diagnostic tool for the detection of Ca with experiments on liquid silicate/metal systems that show metablic malfunctions like osteomalacia or osteoporosis. In the effect of pressure is to make Ni more lithophile than Co order to further investigate Ca isotope fractionation in [3]. But experiments at pressures near the core-mantle vertebrates, we analyzed the Ca isotopic composition ($44/40Ca) boundary are needed to confirm or falsify this conjecture. of diet, feces, blood, bones and urine of Göttingen miniature Also, the provenance of metal melt that supplies Ni may not pigs from an animal trial. Samples of three different groups be restricted to the core. Late accretion of dense metal-bearing were investigated: 1. Control group (Con), 2. chondritic bodies at subsonic velocites may have settled as Glucocorticosteroid induced osteoporosis group (GIO) and 3. piles on the core-mantle boundary [4]. Calcium and vitamin D deficiency induced osteomalacia Olivine phenocrysts in Hawaiian shield lavas have even group (-CaD). 44/40 higher Ni contents than those from BIWG [5]. Ni contents While ' Cadiet values are in average 0.42±0.07 ‰ the can be elevated by reaction of peridotite with either basaltic observed Ca isotope variations in feces, bones, blood and crust or partial melts of basaltic crust to make a second stage urine is significantly higher. '44/40Ca values vary in total by pyroxenite source. Petrological modeling indicates that the 3.28 ‰ ranging from –0.54 ‰ (feces) up to 2.74 ‰ (urine). It Hawaiian peridotite end-member is likely to be Ni-rich, not is not possible to distinguish the three groups solely based on 44/40 44/40 44/40 MORB-like, similar to BIWG. This petrological evidence ' Caurine, ' Cabone or ' Cablood values only. In contrast, 44/40 supports the presence of partial melt at the base of the group –CaD is clearly marked by their low ' Cafeces values. 44/40 Hawaiian mantle plume. Average ' Cafeces of group –CaD is–0.27 ‰ while it is Ultra low velocity zones (ULVZs) may originate by partial 0.39 ‰ and 0.28 ‰ for groups Con and GIO, respectively. 44/40 melting [6] and appear to be irregularly distributed at the The ' Cafeces represents the unabsorbed fraction of boundaries of large low shear velocity provinces (LLSVPs) dietary Ca and thus can be used to identify Ca fractionation 44/40 [7] which are also the proposed sites of mantle plume during intestinal absorption. The ' Cafeces values of –CaD 44/40 generation for both LIPS and ocean islands [8]. ULVZs have are lighter than corresponding $ Cadiet by ~0.6 ‰ which been located below BIWG and Hawaii [7,9], consistent with indicates that Ca isotopes are fractionated during intestinal 44/40 petrological inferences of partial melt. absorption. In contrast, group Con and GIO ' Cafeces values do not indicate Ca fractionation during intestinal absorption. 44/40 [1] Herzberg, Asimow, Ionov, Jackson & Geist (2013), Nature Observed ' Cafeces values of group–CaD may be caused by 493, 393-397. [2] Fiquet et al (2010), Science 329, 1516-1518. either the addition of isotopically light Ca from intestinal [3] Li & Agee (1996), Nature 381, 686-689. [4] Tolstikin & fluids or fixation of light Ca isotopes in unmetabolizable Hofmann (2005), Physics Earth Planet. Inter. 148, 109-130. compounds like Ca oxalates or Ca phytates. [5] Sobolev et al (2007), Science 316, 412-417. [6] Williams & Garnero (1996), Science 273, 1528-1530. [7] McNamara, Garnero & Rost (2010), Earth Planet. Sci. Lett. 299, 1-9. [8] Torsvik et al (2006), Geophys. J. Int., 167, 1447-1460. [9] Cottaar & Romanowicz (2012), Earth Planet. Sci. Lett. 355- 356, 213-222.

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Raman and IR spectroscopy of Searching for evidence for Mo isotope Monazite-type ceramics for the fractionation in the mantle nuclear waste management KATE HIBBERT1*, MATTHIAS WILLBOLD1,2, 1,3 1 1 1 1 MORTEN ANDERSEN AND TIM ELLIOTT J. HEUSER *, A. BUKAEMSKIY , S. NEUMEIER , F. BRANDT1, H. SCHLENZ1, N. DACHEUX2, N. CLAVIER2, 1Bristol Isotope Group, School of Earth Sciences, University A. NEUMANN3, A. HIRSCH3, D. BOSBACH1 of Bristol, Bristol, UK (*correspondence: [email protected]) 1Forschungszentrum Juelich GmbH, Institute of Energy and 2Department of Earth Science and Engineering, Imperial Climate Research - IEK-6: Nuclear Waste Management, College London, London, UK D-52425 Juelich, Germany (*correspondence: 3Institute of Geochemistry and Petrology, ETH Zurich, [email protected]) 2 Switzerland Institut de Chimie Séparative de Marcoule, ICSM UMR 5257

– CEA / CNRS / UM2 / ENSCM, Site de Marcoule, BP Molybdenum is a highly siderohpile element which was 17171, F-30207 Bagnols sur Cèze Cedex, France 3 strongly depleted in the mantle by the process of core RWTH Aachen University, Institute of Crystallography, D- formation. Its mantle inventory is therefore strongly 52066 Aachen, Germany influenced by the addition of material during the late veneer

when highly siderophile elements were enriched in the mantle Lanthanide monazite-type (LnPO ) ceramics are promising 4 after core formation. candidate materials for the immobilisation of minor Recent experimental data suggest that molybdenum resulting from reprocessing of spent fuel. Particularly with isotopes are fractionated during metal-silicate equilibration, regard to the long-term safety in a deep geological repository, with lighter isotopes preferentially entering the silicate phase monazite-type ceramics present a good alternative to the [1]. Therefore the mantle should be isotopically lighter than widely used borosilicate glasses for the specific conditioning the chondritic material which is presumed to have accreted to of actinides. In terms of their crystal structure (SG P 2 /n) they 1 form the Earth as heavy isotopes were concentrated into the offer outstanding properties concerning radiation resistance core. However, the addition of the late veneer may have and chemical stability. Their normalised dissolution rates are somewhat obscured the isotopic signature of core formation. several orders of magnitude lower than these of glasses [1-4]. We describe two approaches taken to investigate the This behaviour can also be confirmed by their natural isotopic composition of the mantle relative to chondrites in an analogues (no metamictisation occurs). attempt to verify these experimental findings. Firstly, we Therefore we investigated different monazite-type phases measure a range of ~3.8Ga samples from Greenland which as potential waste forms for minor actinides. We prepared and have been shown to retain an isotopic signature of the mantle characterised SmPO -TbPO and SmPO -CaTh(PO ) solid 4 4 4 4 2 prior to the addition of the late veneer [2]. solutions, using wet-chemical synthesis routes like Secondly, we measure the Mo isotopic composition of precipitation at room temperature and solid state reactions mid-ocean ridge basalts (MORBs) which we compare to (1600 °C), respectively. The presented data obtained by chondrite samples in an effort to detect residual fractionation Raman and IR spectroscopic investigations will be discussed of molybdenum isotopes associated with core formation post in conjunction with X-ray powder diffraction data as well as late veneer. thermal analyses within a comparison to the available MORB samples are known to carry some signature of literature. An increasing distortion of the PO tetrahedra 4 recycling; however we suggest that they are sufficiently should be demonstrated with increasing Th-substitution of the representative of the mantle for our purposes. Whilst scatter in Ln-position. Additionally, the monazite-cheralite solid both the MORB and chondrite datasets currently prevents the solution data will be compared to that of a Thorium containing identification of a resolvable difference, we find a tantalising natural monazite sample. Completely new data could be offset of 0.1 permil between the most primitive MORB sample generated for the solid solutions. Results of temperature and the least altered chondrite. dependent Raman spectroscopic investigations on the partly

metastable (Sm,Tb)PO solid solutions will be presented, 4 [1] Hin et al, AGU Fall Mtg, abs #P11A-1588 [2] Willbold et where depending on the composition one-two exothermic al, (2011) Nature 477, 195-198 phase transitions are expected.

[1] Meldrum et al (1997) Phys. Rev. B 56, 13805-13814 [2]

Lumpkin (2006) Elements 2, 365-372 [3] N. Dacheux et al (2004) Comptes Rendus Chimie 7, 1141-1152 [4] Schlenz et al (2013) Z. Krist. 228, III, 113-123

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Isotopic evidence for an activity of Fulvic and Humic Acid interaction the early Sun studied from the with Phosphate at synthetic and isotopic measurements of Kapoeta natural oxide surfaces HIROSHI HIDAKA1 AND SHIGEKAZU YONEDA2 TJISSE HIEMSTRA1, SHAMIM MIA, PIERRE-BENOÎT

1 DUHAUT, AND BASTIAAN MOLLEMAN Department of Earth and Planetary Systems Science, Hiroshima University, Higashi-Hiroshima 739-8526, 1Dept. Soil Quality, PO box 47, 6700 AA, Wageningen Japan ([email protected]) University, Netherlands [email protected] 2Department of Science and Engineering, National Museum of Nature and Science, Tsukuba 305-0005, Japan Fulvic acid (FA) and humic acid (HA) have a large variability in binding to metal (hydr)oxides and interact The Kapoeta meteorite (howardite) is a regolith differently with oxyanions, as studied experimentally for meteorite, and is known to be a highly gas-rich meteorite that goethite, phosphate, and a series of soil HAs that cover the experienced early irradiation by cosmic rays, however, its large natural variation in molecular charge and size. A surface irradiation history is complicated and still disputed with complexation approach has been developed that aims to respect to evidence of early solar irradiation. Our previous describe the pH-dependent competitive behaviour of natural study on neutron capture history of Kapoeta suggests the organic matter (NOM) in soil as well as model (hydr)oxide existence of preirradiation materials migrating into the systems, using variable inner and outersphere complexation as meteorite parent body [1]. The existence of space-weathered well as protonation of RCOO ligands. rims in several regolith grains in the Kapoeta meteorite is Modelling shows that the competition of phosphate with resulted from the irradiation of cosmic-ray on the regolith various HAs is linearly related to the HA charge. Expressed parent body [2]. In this study, Sr, Ba, Ce, Nd, Sm and Gd per unit charge, HA competes as well as FA (or even better), isotopic compositions of the sequential acid- leachates from which is unexpected since the various humics highly differ in the Kapoeta meteorite were determined to find systematic and molecular size (~1-10 nm) suggesting variation in mean correlated variations of their p-process isotopic abundances distance of approach [1]. Modelling suggests that at low and to understand the neutron capture record due to cosmic- loading, both FA and HAs are predominantly adsorbed in the ray irradiation. Stern layer domain which points to a strong change of the Significantly large isotopic excesses of 84Sr, 130Ba, 132Ba, molecular conformation of the humic acids. Our calculations 136Ce, 138Ce and 144Sm were observed particularly in the first suggest that the metal (hydr) oxide surfaces are efficiently leaching fraction (L1). Interestingly, a large isotopic shift of covered by an ultra-thin layer of NOM. Therefore, realistic 150Sm/149Sm and 158Gd/157Gd due to neutron capture reactions surface complexation modeling of natural systems should was also found in the first fraction, corresponding to the account for this pervasive NOM surface coverage. neutron fluence of 2.6x1016 n cm-2, which is more than 10 From the perspective of global carbon sequestration, times higher than those in the other fractions. The large adsorption of NOM is also important since minerals may difference of neutron capture records of L1 from the other protect adsorbed carbon against oxidation. In soils, the three suggests the existence of preirradiation materials reactive metal (hydr)oxide fraction consists of nanoparticles, migrating into the Kapoeta parent body. typically representing ~3-30 m2 g-1 soil [2]. When covered by Systematic isotopic data in this study reveal the an ultra-thin layer of NOM, it may represent at least 0.2-2% enrichment of several p-process isotopes of the fraction L1 NOM. Surface-associated NOM may be even three times leached probably from a very surficial part of regolith grains higher. In our competition study, we have also included of Kapoeta, suggesting the production of p-process isotopes pyrogenic HA since it will be released to the environment in resulted from the interaction of SCR during the regolith case of large-scale application of biochar, potentially creating process of the Kapoeta parent body. The result provides Darks Earths or Terra Preta soils. Terra Preta soils are fertile, isotopic evidence for an activity of the early Sun. rich in carbon as well as phosphate. Our charge distribution model for NOM predicts a more than 10-fold increase in [1] Hidaka and Yoneda (2009) EPSL 285, 173–178. [2] Noble dissolved phosphate for soils rich in black carbon. This is due et al (2011) MAPS 45, 2007-2015. to the relatively high molecular charge of pyrogenic HA.

[1] Weng et al (2007) J. Colloid Interf. Sci. 314, 107-118. [2] Hiemstra et al (2010) Geochim. Cosmochim. Acta 74, 41-58.

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Multi-stage Cl-rich fluid activity and Magnesium isotope evidence for a behavior of REE-bearing minerals in link between low-temperature clays, a Neoproterozoic granulite terrane seawater Mg/Ca, and climate FUMIKO HIGASHINO1*, TETSUO KAWAKAMI1, HIGGINS, J.A.1* AND D.P. SCHRAG2 2 3, M. SATISH-KUMAR , MASAHIRO ISHIKAWA 1 Dept.of Geosciences, Princeton University, NORIYOSHI TSUCHIYA4 AND GEOFF GRANTHAM5 ([email protected]) 1Department of Geology and Mineralogy, Kyoto University, 2Dept. of Earth and Planetary Science, Harvard University, Japan (correspondance: [email protected]) ([email protected]) 2Niigata University, Japan 3Yokohama National University, Japan Cooling of Earth’s climate over the Cenozoic has been 4Tohoku University, Japan accompanied by large changes in the magnesium and calcium 5Council for Geoscience, South Africa content of seawater. The processes that control these changes affect the magnesium isotopic composition of seawater, Cl-rich fluid is a powerful solvent, and can coexist with rendering it a useful tool for elucidating the processes that

CO2-rich fluid under granulite facies conditions [1]. Despite control seawater chemistry. We use measurements of such important roles, the scale and timing of its activity during magnesium isotopes in both pore fluids and carbonate high-grade metamorphism are still not clear. Field distribution sediments together with a numerical model of sediment of Cl-rich biotite, amphibole and apatite, which are evidence diagenesis and show that the magnesium content of seawater for the presence of Cl-rich fluid, is investigated in detail in the has increased by 10-15 mmol over the last 15-25 Myr with Sør Rondane Mountains (SRM), East Antarctica where little change in its isotopic composition. These observations granulites are widely exposed. are best explained by a reduction in removal of Mg from Cl-rich biotite preserved as inclusions in garnet shows seawater in marine clays formed at low temperatures. A linear distribution in the SRM. Among them, a pelitic gneiss temperature-dependent Mg sink in marine clay directly links from the east SRM (Balchenfjella) shows Cl-rich fluid the major element chemistry of seawater to global climate, infiltrated around near-peak metamorphism at ca. 800 ºC, 0.8 providing an additional explanation for the co-variation of GPa [2]. In this sample, monazite is present in the garnet core, seawater Mg/Ca and climate on ~100 million year timescales whereas zircon and xenotime are included in the garnet rim. over the Phanerozoic. This suggests that the Cl-rich fluid infiltration that took place at the garnet core/rim boundary lead to the change of REE- bearing mineral species. This implies that Cl-rich fluid carried LREE and Th away and brought HREE, Zr and Y in. U-Pb dating of zircon included in the garnet rim gave 603±14 Ma [2], representing the timing of Cl-rich fluid infiltration. Biotite in the matrix is Cl-poor, suggesting that the retrograde metamorphism occurred in a Cl-poor environment. The rim of zircon in the matrix might represent a timing of this fluid activity (564±17 Ma), which is consistent with the zircon ages obtained from metacarbonates (ca. 545 Ma) that represent the timing of fluid activity [3, 4]. In addition, the mafic gneisses from the central SRM (Brattnipane) host cm-thick veinlets composed of garnet and Cl-rich amphibole that discordantly cut the penetrative gneissosity. In our presentation we discuss the processes associated with multi-stage Cl-rich fluid infiltration in the SRM during the peak- to retrograde stages.

[1] Newton & Manning (2010) Geofluids 10, 58-72. [2] Higashino et al (2013) Precam. Res. in press. [3] Higashino et al (2013) JpGU abst. [4] Otsuji et al (2013) JpGU abst.

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Holocene records of chlorin Efficient preservation of terrestrial N isotopes organic carbon offshore Taiwan: MEYTAL B. HIGGINS1, REBECCA S. ROBINSON2 Implications for the global carbon AND ANN PEARSON3 cycle 1 Department of Geosciences, Princeton University; 1, 2,3 R. G. HILTON * AND S. J. KAO [email protected] 2Graduate School of Oceanography, University of Rhode 1Durham University, United Kingdom, (*correspondence: Island; [email protected] [email protected]) 3Department of Earth and Planetary Sciences, Harvard 2Academia Sinica, Taiwan, ([email protected]) University; [email protected] 3Xiamen University, China.

Nitrogen isotope ratios measured in sedimentary Photosynthesis on land produces terrestrial biomass and chlorophyll degradation products provide a diagenetically sequesters atmospheric CO2 within living matter. Geological unaltered signal of the marine nitrogen cycle during sequestration of CO2 can occur if this terrestrial organic carbon deposition. Additionally, due to taxonomic differences in (OC) is eroded and transported to marine sediments where fractionation associated with chlorophyll biosynthesis, these accummulation rates are high1, influencing Earth’s radiation records can be used to reconstruct the cyanobacterial energy balance. Mountain rivers draining islands of Oceania contribution to buried organic matter. If diazotrophic have amongst the highest erosion rates of terrestrial OC and cyanobacterial contribution to biomass increases during sediment2,3 and it is of critical importance to understand its fate 14 enhanced N2 fixation, then chlorin N isotope records may upon entering the ocean. Here we use radiocarbon (, Corg, 13 provide an additional constraint on the importance of this ‰), stable isotopes (' Corg, ‰) and OC content (Corg, %) to source of N to surface waters in the geologic past. We track terrestrial OC from Taiwan from river sediments to reconstructed low resolution records of chlorin !15N values ocean sediment traps and box-cores collected from around the from the last glacial maximum to recent sediments in four island. We account for fossil OC from sedimentary rock, while oceanographically distinct settings. Samples were taken from assessing the range of delivery mechanisms to the ocean by ODP sites 1234 (Chile Margin), 1237 (Nazca Ridge, Peru), mountain rivers. 1063 (Bermuda Rise), and core 17964 from the South China During floods at high suspended sediment concentrations, Sea. These four globally-distributed sites represent different we observe efficient transfer of terrestrial OC (both fossil and nutrient regimes characterized by a wide range of modern P* non-fossil) to the deep ocean, and evidence for its longer-term 15 values and potential rates of N2 fixation. Chlorin ! N data presveration in marine sediments. Large amounts of terrestrial were compared to new or previously published bulk N data to sediment are also delivered to the surface ocean by rivers, examine for diagenetic enrichment of bulk N (causing 15N dispersing OC over a larger area3. Marine sediments sourced offsets to increase) or cyaobacterial contribution to export by this mechanism have a positive relationship between 15 14 13 (causing N offsets to decrease). Preliminary data show an , Corg and ' Corg, and a negative relationship between 1/Corg 15 14 average ! N offset of ~5-5.5‰ between bulk and chlorin N at and , Corg. Employing end member mixing analysis and by all sites, suggesting predominantly algal export production modelling OC loss scenarios, we show that these are the 15 irrespective of N2 fixation regime and bulk values of ! N. product of mixing between marine OC and terrestrial OC (itself a fossil and non-fossil mixture) and that 80-100% of terrestrial OC is preserved in marine sediments, suggesting much higher burial efficiencies than previously hypothesed2.

Our findings allow for a conservative estimate of recent CO2 sequestration by terrestrial OC burial across Oceania, which comprises a significant proportion of global OC burial. We thus postulate that tropical mountain islands provide a strong coupling between tectonic uplift and the carbon cycle, one that is moderated by the climatic variability that controls terrestrial OC delivery to the ocean.

[1] Galy et al (2007) Nature 450, 407-410. [2] Hilton et al (2012) Global Biogeochemical Cycles 26, GB3014. [3] Kao & Milliman (2008) Journal of Geology 116, 431-448.

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Experimental determination of the Si Combining radiogenic and stable Ca isotope fractionation factor between isotopes to explore sub-glacial metal and silicate liquids weathering reactions REMCO C. HIN1, CAROLINE FITOUSSI1,2, R. HINDSHAW1*, B. BOURDON2, J. RICKLI3 AND MAX W. SCHMIDT1 AND BERNARD BOURDON1,2 J.WADHAM4 1Institute of Geochemistry and Petrology, ETH Zurich, 1Øystein Møylas veg 16, Trondheim, Norway Switzerland (*correspondence: [email protected]) (correspondence : [email protected]) 2Ecole Normale Supérieure de Lyon and CNRS, France 2Laboratoire de Géologie de Lyon, ENS Lyon, France 3Institute of Geochemistry and Petrology, ETH, Switzerland The conditions of core formation on Earth are still debated 4Bristol Glaciology Centre, University of Bristol, UK and stable isotope fractionation is explored as a new tool to further constrain metal-silicate segregation conditions. It has The interpretation of weathering processes based on the been shown that chondrites and (ultra)mafic terrestrial silicates stable isotopes of calcium (Ca) is complicated by the difficulty have different Si isotope compositions1-3, although there is no of distinguishing between source and process fractionation consensus yet4. Recent experimental work has found effects. The combination of radiogenic Ca isotopes (*40Ca) -1.77±0.32‰ fractionation between liquid metal and olivine at with stable Ca isotopes ('44/42Ca) would provide the ability to 1800°C5, which implies that Si isotope fractionation may separate source and process fractionation effects. The aim of occur during core formation in planetesimals and on Earth. this study was to combine both the stable and radiogenic Ca To better constrain the conditions of core formation, Si isotope systems to investigate the sources of Ca and Ca isotope fractionation between metal and silicate must be well isotope fractionation processes in glaciated environments, calibrated. We therefore performed liquid metal, liquid silicate providing great potential to increase understanding of the equilibration experiments at 1450°C and 1750°C at 1 GPa in a behaviour of Ca during weathering. centrifuging piston cylinder at ETH Zurich. The physically This study is based on a one month sampling campaign to segregated liquids were mechanically separated prior to Leverett Glacier, West Greenland in July 2009. The bedrock dissolution by alkali fusion. After ion exchange (granite/gneiss) is of Archean age (ca 1850 Ma), theoretically 40 chromatography, isotopic analyses were carried out on a Nu old enough to have acquired radiogenic Ca anomalies. Water Instruments 1700 MC-ICPMS at ETH Zurich. samples were collected twice daily for a period of 28 days The silicate liquids had consistently heavier Si isotopes together with spot samples of water end-members (ice, supra- than the equilibrated metal liquids. The average fractionation glacial water) and four representative rock samples from 30 factor between metal and silicate liquids (, SiMetal-Silicate) was which the main Ca bearing minerals were separated. -1.48±0.08‰ at 1450°C and -1.11±0.14‰ at 1750°C. Given a The bulk rock samples exhibit a range in both stable 1/T2 functional form, the temperature dependence of Si ('44/42Ca = +0.20 to +0.50‰) and radiogenic (*40Ca = -1.0 to isotope fractionation between metal and silicate liquids can be +6.9) Ca isotopic compositions. Two of the analysed mineral 30 6 2 described as , SiMetal-Silicate (‰) = -4.47(±0.31)$10 /T . separates had significant radiogenic Ca anomalies: sanidine Our equilibrium data yield a smaller fractionation than (*40Ca = +15.3) and biotite (*40Ca = +7.7). Radiogenic previously deduced5. Calculations at 2500-3500 K for metal- anomalies up to *40Ca = +5.3 were detected in river water silicate equilibration during core segregation on Earth imply a samples, coincident with an outburst event. The change in bulk Earth '30Si of -0.38 to -0.33 (±0.02‰ propagated error), *40Ca measured in the river water samples during the outburst respectively, for a bulk silicate Earth '30Si of -0.29±0.01‰ event indicates a change in the relative contribution from and 6 wt% Si in the Earth’s core. Although the calculated different mineral sources to the dissolved load of Ca. In values fall in the range of observed chondrite Si isotope contrast, the stable Ca isotopic composition of river water compositions, they do not match all observations for the Si showed no discernable temporal variation and had an average isotope composition of chondrites. '44/42Ca of +0.60‰, which was significantly higher than the source rocks. The combination of *40Ca and '44/42Ca data [1]. Georg et al, 2007. Nature 447, 1102-1106. [2] Fitoussi et clearly indicates that '44/42Ca values cannot be reconciled with al, 2009. EPSL 287, 77-85. [3] Armytage et al, 2010. GCA 75, mixing processes and have been fractionated. 3662-3672. [4] Chakrabarti and Jacobsen, 2010. GCA 74, 6921-6933. [5] Shahar et al, 2011. GCA 75, 7688-7697.

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Effect of phosphate and sulfate on The future of lipids as tools to study Fe(II)-catalyzed trace metal microbes and biogeochemical incorporation into and release from processes in the deep biosphere Fe(III) oxides KAI-UWE HINRICHS1*, JULIUS S. LIPP1, 1 1,2 1 1 1 TRAVIS B. MEADOR , GUNTER WEGENER , SITAN XIE MARGARET ANNE G. HINKLE *JEFFREY G. CATALANO 1MARUM-Center for Marine Environmental Sciences, 1Earth & Planetary Sci., Washington Univ., St. Louis, MO University of Bremen, 28359 Bremen, Germany 63130 USA (*correspondence: [email protected]) (*Presenting author, [email protected]) 2Max Planck Institute for Marine Microbiology, 28359 Trace element concentrations in natural systems are often Bremen, Germany controlled by adsorption-desorption reactions on iron oxide

surfaces [1]. Biogeochemical iron cycling leads to the Recent work has demonstrated that the predominant coexistence of aqueous Fe(II) with solid Fe(III) oxides, which microbial intact polar lipids (IPLs) in marine sediments, i.e., undergo Fe(II)-Fe(III) interfacial electron transfer and atom glycerol-based ether lipids with a glycosidic polar headgroup, exchange (ET-AE) reactions [2]. These reactions result in are impacted by a considerable fossil fraction derived from Fe(III) oxide recrystallization, causing the incorporation of past microbial generations [1]. Although IPL concentration structurally compatible adsorbates, e.g. Ni(II), into solid profiles provide useful quantitative constraints on slowly Fe(III) oxides as well as the release of preincorporated ions growing archaeal communities [1], their use as direct markers into solution [3-5]. Recent research has shown that oxoanions of live biomass in deeply buried sediments is compromised. common to natural systems, such as phosphate, do not affect Hence lipid-based investigative strategies will have to be the rate or extent of Fe(II)-Fe(III) atom exchange reactions modified in order to sustain a central role of microbial lipids in [6]. However, these species may still potentially alter trace future studies of subseafloor life. metal incorporation and release by complexing with metals at Future avenues will need to focus on IPLs that have little the iron oxide surface or by changing growth and dissolution or no fossil bias, such as phospholipids [cf. 1] or new target mechanisms via processes such as step pinning. compounds that are diagnostic for actively growing cells as We have investigated the interaction of phosphate and identified by culture studies. Detection of these often far less sulfate with Fe(II) on goethite and hematite surfaces and the abundant compounds will require implementation of more resulting impact on Ni incorporation and release. sensitive approaches [2]. Some novel groups of orphan lipids Macroscopic adsorption and ATR-FTIR studies demonstrate are concentrated in the subseafloor [3]; the elucidation of their that oxoanions enhance Fe(II) adsorption through a direct biological sources and function will likely provide important interaction on the mineral surface. XAFS spectroscopy clues on the deep biosphere. Novel, minimally invasive stable indicates that both phosphate and sulfate decrease Fe(II)- isotope probing assays that target microbial lipids will have a catalyzed Ni(II) incorporation into goethite and hematite; the key role in quantifying microbial growth and substrate effect of phosphate was more substantial. Ni(II) release from specificity [4]. This paper will review the state-of-the-art and these minerals during Fe(II)-catalyzed recrystallization was provide new examples that illustrate future directions of lipid- also suppressed by phosphate and sulfate, with the former based research of subseafloor life. again producing the larger inhibititory effect. This research suggests that phosphate and sulfate affect trace element partitioning between aqueous solutions and Fe(III) oxides [1] Xie et al (2013) PNAS 110, 6010-6014. [2] Wörmer et al during Fe(II)-Fe(III) ET-AE reactions, potentially impacting (2013) Org. Geochem. doi:10.1016.2013.03.004. [3] Liu et al contaminant fate and micronutrient bioavailability in soil and (2012) Rap. Comm. Mass Spectrom. 26, 2295-2302. [4] aquatic environments. Wegener et al (2012) Env. Microbiol. 14, 1517-1527.

[1] Brown & Parks (2001) Int Geol Rev 43, 963-1073. [2] Handler et al (2009) Environ Sci Technol 43, 1102-1107. [3] Yanina & Rosso (2008) Science 320, 218-222. [4] Frierdich & Catalano (2012) Environ Sci Technol 46, 1519-1526. [5] Frierdich, Luo & Catalano (2011) Geology 39, 1083-1086. [6] Latta, Bachman & Scherer (2012) Environ Sci Technol 46, 10614-10623.

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Complex in situ cosmogenic 10Be-14C Mantle structure below the petit-spot data suggest Mid-Holocene climate N. HIRANO1*, J. YAMAMOTO2 AND S. OKUMURA3 change on the Bolivian Altiplano 1Center NE-Asian Studies, Tohoku Univ., Japan 1 2 1 3 (*correspondence: [email protected]) K. HIPPE *, F. KOBER , S. IVY-OCHS , M. LUPKER , 2 1 1 3 Hokkaido Univ. Museum, Hokkaido Univ., Japan L. WACKER , M. CHRISTL AND R. WIELER 3Dept. Earth Sci., Tohoku Univ., Japan 1Laboratory of Ion Beam Physics, ETH Zürich, 8093 Zürich, Switzerland (*correspondence: [email protected]) The petit-spot volcanoes, erupted due to lithospheric 2Institute of Geology, ETH Zürich, 8092 Zürich, Switzerland 3 bending related to the plate subduction, were found on the Isotope Geology and Mineral Resources, ETH Zürich, subducting plate off Japan and Chile trenches [1, 2]. An old 8092 Zürich, Switzerland and flexed lithosphere might cause brittle fractures at the 3 Institute of Geochemistry and Petrology, ETH Zürich, 8092 upper lithosphere. Incipient melts in the asthenosphere can be Zürich, Switzerland squeezed upward by tectonic forces associated with plate flexure [1]. The presence of the tiny submarine volcanoes, In a recent study on basin-averaged denudation rates on petit-spot, is an important indicator of the stress field of the the Bolivian eastern Altiplano, long-lived 10Be and 26Al have plate [3], in addition to providing information on the been used to provide long-term estimates on sediment geochemical composition of the mantle below the petit-spot production while the short-lived in situ 14C allowed to identify [4, 5, 6, 7]. interruptions of sediment exposure by episodes of sediment The lavas and entrained xenolithes were newly dated and storage [1]. Based on comparatively low in situ 14C analyzed in this study. Accordingly, monogenetic petit-spot concentrations sediment storage over at least the past 11- 20 volcanoes located on the NW Pacific Plate yield ages of 1.8, ka has been suggested. 3.8, 4.2, 6.0, 6.2, 8.5, and 9.2 Ma by Ar-Ar datings, suggesting Following this approach, we have chosen to focus on one the episodic eruption of magma over a large eruption area 2 single catchment on the eastern Altiplano (~350 km ) to trace (over 800 km of plate motion) of the concave part of the plate, the spatial pattern of sediment deposition and quantify but with low volumes of magma production [8]. Most of lavas individual storage durations. Sediment samples were taken have the differentiated composition of approximately 50 wt% along the main channel and from tributaries as well as from SiO2 and 60 of Mg number with extremely high contents of 10 three hilltop sites. Results from the analysis of Be and in situ . The petrography and geobarometer of 14 C are in agreement with previous data [1] showing a high peridotitic xenolithes show that they rapidly ascended through 10 14 Be content and significantly too low in situ C the upper lithosphere. These data implies the magma concentrations for all but one sample, including two of the differentiated at the depth deeper than middle of lithosphere three hilltop samples. Excluding sediment storage/burial on where the carbon dioxide does not exsolve in magmas. the hilltop for obvious reasons and excluding soil mixing or slab breakoff from field observations, we propose a change in [1] Hirano et al (2006) Science 313, 1426-1428. [2] Hirano et 10 denudation rate to account for the discrepancy of Be and in al (2013) Geochem. J. 47, in press. [3] Valentine & Hirano 14 situ C on the hilltop. Using a simple model of a rapid, one- (2010) Geology 38, 55-58. [4] Machida et al (2009) Geochem. step denudation increase, the two samples suggest a minimum Cosmochim. Acta 73, 3028-3037. [5] Hirano (2011) 30-40 times increase in denudation rate about 4-6 ka ago. Geochemi. J. 45, 157-167. [6] Yamamoto et al (2009) Assuming that the analyzed fluvial sediments have already Chemical Geol. 268, 313-323. [7] Machida et al (2013) 10 14 an inherited complex Be- C signal from the sediment- MinMag, this volume. [8] Hirano et al (2008) Basin Res. 20, producing hilltop areas, the total duration of sediment storage 543-553. reduces to ~1-5 ka, thus much shorter than previously assumed. Our data further show that sediment storage occurring on the floodplain does not contribute to the complex signal. In contrast to the channels in the upstream area, that incise a few metres in depth, the material deposited on the floodplain is apparently only rarely reworked.

[1] Hippe et al (2012) Geomorphology 179, 59-70.

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Heavy element-stable isotope Crystal structure in systematics for metallomics induced Earth’s inner core by the MC-ICPMS technique KEI HIROSE1*, SHIGEHIKO TATENO2 A 1,3 1 1 ND HARUKA OZAWA TAKAFUMI HIRATA , SATOKI OKABAYASHI , TAKESHI OHNO2, KAZUMI YOSHIYA3, 1Earth-Life Science Institute, Tokyo Institute of Technology, TSUYOSHI KOMIYA4 AND SHIGENORI MARUYAMA3 Tokyo, Japan (*Correspondence: [email protected]) 2Department of Earth and Planetary Sciences, Tokyo Institute 1Dept. of Earth and Planet. Sci., Kyoto Univ. Japan of Technology, Tokyo, Japan ([email protected]) 3 2 Institute for Research on Earth Evolution, Japan Agency for Dept. of Chem., Gakushuin Univ., Japan Marine-Earth Science and Technology, Yokosuka, Japan 3Dept. of Earth and Planet. Sci., Tokyo Inst. of Techn., Japan 4 Dept. of Earth Sci. and Astro., Komaba, Univ. Tokyo, Japan Composition and state of the core remain uncertain to a large extent [1], in part because static experiments performed Continuous developments in inorganic mass spectrometry on candidate compositions at such extreme conditions have techniques, including a combination of an ICP ion source and been difficult until recently. Nevertheless, ultrahigh-pressure a magnetic sector-based mass spectrometer equipped with a experimental techniques using laser-heated diamond-anvil cell multiple-collector array (MC-ICPMS), have revolutionized the (DAC) combined with synchrotron x-rays have greatly precision of the isotopic ratio measurements. Although the advanced in recent years. Now static experiments are being magnitude of many analytical problems is clearly exacerbated, performed at the core ultrahigh pressure and temperature the analytical community is actively solving problems, such as conditions, even beyond those at the center of the Earth [2]. spectral interference, mass discrimination drift, high-yield Recent experimental and theoretical studies indicated that chemical separation and purification processes, or reduction of hexagonal-close-packed (hcp) structure is a stable form of iron the contamination of analytes, and the applications of the in the Earth’s inner core. Earlier calculations suggested that heavy element-stable isotope geochemistry are beginning to body-centered-cubic (bcc) Fe is stable above ~5500 K at 330 appear over the horizon [1, 2]. The variations in isotopic GPa [4]. However, the temperature at the inner core boundary ratios of the heavy elements, such as Fe, Zn, Cu, Sr, Ce-Nd, may be as low as 5200 K, inferred from recent estimates of W, or U can provide new insights into past and present core-mantle boundary temperature of ~3800 K. The nature of geochemical and biochemical processes [2]. Among the stable crystalline phases and physical properties are strongly heavy elements, mass-dependent isotopic fractionation of the affected by impurity elements in the core. We have performed bioessential metals (e.g., Ca, Fe, Zn or Cu) was extensively x-ray diffraction measurements so far up to 412 GPa and 5900 applied to investigate the nutritional status of elements or to K and examined stable crystal structures of iron-compounds evaluate the elemental metabolism for plant and animals [e.g., including Fe-10wt%Ni, FeO, Fe-9wt%Si, and Fe-S alloys 1,3,4]. This is well demonstrated by the diagnosis for specific under the core conditions. Considering a small density deficit, diseases through the changes in isotope ratios of the elements our data so far suggest that hcp is a plausible crystal structure [5,6]. To take a full advantage of the heavy element-isotope in the inner core. systematics, we are currently trying to obtain in situ isotope

ratio data of the elements using MC-ICPMS technique [1] Hirose et al (2013) Annu. Rev. Earth Planet. Sci., 41, coupled with a femtosecond-laser ablation sample introduction 10.1146/annurev-earth-050212-124007. [2] Tateno et al technique (fLA-MC-ICPMS). Analytical advantages achieved (2012) AGU Fall Meet., Abstr. DI12A-04. by the fLA-MC-ICPMS technique or by the LAL-MC-ICPMS technique [7] will be presented in this presentation.

[1] Maréchal et al (1999) Chem. Geol. 156, 359-396. [2] Tanimizu et al (2013) Anal. Bioanal. Chem., 405, 2771-2783. [3] Bullen and Walczyk (2009) Elements 5, 381–385. [4] Moynier et al, (2009) Chem. Geol. 267, 125–130. [5] Walczyk, von Blanckenburg (2002) Science 295, 2065–2066. [6] Aramendia et al (2013) J. Anal. Atom. Spectrom. doi: 10.1036/c3ja30349g. [7] Okabayashi et al (2011) J. Anal. Atom. Spectrom. 26, 1393-1400.

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Deep Time: How did the early Earth Chemical diffusion in the deep Earth: become our modern world? Is it all about grain boundaries? MARC M. HIRSCHMANN MATTHEW HISCOCK1 AND GEOFFREY D. BROMILEY1 U. Minnesota, Minneapolis, MN USA ([email protected]) 1School of GeoSciences (Grant Institute) and Centre for Science at Extreme Conditions, University of Edinburgh, One of the salient challenges in Deep Time studies is Edinburgh EH9 3JW, UK understanding how the Earth made the transition from early violent events –accretion, core formation, and impacts– to the Diffusion of chemical species in Earth's interior plays a rather normal equable conditions recorded in the Hadean Jack controlling role in many of the large-scale processes which Hills zircons, with oceans, granitic crust derived in large part first formed and continue to reform the Earth through time. from partial melting of mature sediments, and perhaps even Traditionally, diffusivity of species has been considered to dynamical behavior similar to plate tectonics1. An unresolved occur under subsolidus conditions mainly via lattice diffusion; question is how the Earth’s deep volatile cycles evolved i.e. the movement of species through bulk crystal structures. through this time. One interpretation is that the combination Recently however, researchers have started to attempt to of core formation, magma ocean degassing, and atmospheric constrain the importance of grain boundary diffusion (GBD) loss produced an early mantle largely devoid of volatiles, in the deep Earth: i.e. the mobility of species along grain which were then added chiefly in a late veneer. But if the late boundaries. Grain boundaries provide alternative, fast veneer was mixed in to the mantle only gradually over time pathways for mobile species which may be chemically and scales of > 1 Ga2, then the Hadean near surface environment structurally very distinct from the bulk crystalline structure of would have been dominated by super-oceans, flooding polymineralic materials. It has recently been suggested that protocontinents and massive supracrustal storage of C, GBD provides a mechanism for transporting highly presumably as carbonate. Similarly, the consequences of a incompatible elements from the core into regions of lower nearly volatile-free mantle on mantle dynamics and tectonics mantle melting, and is an important component of H mobility are poorly understood. However, there is reason to believe in the upper mantle. Here we present results from an that a significant portion of Earth’s present-day volatiles were experimental study aimed at constraining the importance of delivered to the mantle prior to the late veneer. At a GDB in 3 geochemically important but contrasting systems: H minimum, the distinct noble gas compositions of the mantle mobility in olivine, Li diffusion in olivine and Ti diffusion in and atmosphere require retention of some early (including quartz. nebular) volatiles in the mantle. But more importantly, H/C3 Experimental data demonstrate similar diffusivities for and N/C4 ratios of the bulk silicate Earth demonstrate that GBD and lattice diffusion of H under mantle conditions. Earth’s major volatile inventories remember the processing When scaled to mantle grain sizes, results suggest that GBD of associated with magma ocean and core formation stages, H is of minor importance, except at marked discontinuities in suggesting that significant fraction of Earth’s early volatiles the mantle where there are abrupt changes in H solubility. In avoided catastrophic escape or core sequestration. The contrast, data suggest that GBD of Li is between 2 and 4 mechanisms of this retention are poorly understood, but may orders of magnitude faster than lattice diffusion. Differences have been critical to the early approach to dynamical and in the behaviour of H and Li can be understood in terms of climatic stability. incorporation mechanisms and the contrasting nature of crystalline material vs relatively amorphous grain boundaries. [1] Hopkins et al (2008) Nature 456 493-456. [2] Maier et al Critically, these differences result in contrasting temperature (2009) Nature 460 620-623.[3] Hirschmann&Dasgupta (2009) dependences for GB vs lattice diffusion which imply that Chem. Geol. 262 4-16. [4] Marty (2012) EPSL 313 56-66. GBD always dominates at low temperatures. Similarly, we find that GBD of Ti in polycrystalline quartz is orders of magnitude faster than lattice diffusion, as result which has immediate implications for the applicibility of the Ti in quartz geothermometer. Based on these results, we present a predicitive model for determining the relative importance of GBD in the deep Earth.

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Release of antimony from The role of earthworm-produced contaminated soil induced by redox CaCO3 in the terrestrial calcium and changes carbon cycles KERSTIN HOCKMANN1*, SUSAN TANDY1, MARKUS LENZ2 MARK E. HODSON1*, EMMA A. A. VERSTEEGH2 AND AND RAINER SCHULIN1 STUART BLACK3 1 1Institute of Terrestrial Ecosystems, ETH Zurich, Switzerland, Environment Department, University of York, Heslington, (*correspondence: [email protected]) York YO10 5DD, UK, ([email protected] 2University of Applied Sciences and Arts Northwestern *presenting author) 2 Switzerland (FHNW), Institute for Ecopreneurship, Department of Geography and Environmental Science, Muttenz, Switzerland University of Reading, Reading RG6 6DW, UK, ([email protected]) 3 Due to its rapid growth in industial use, soil contamination Department of , University of Reading, Reading by antimony (Sb) has become a matter of increasing RG6 6AB, UK, ([email protected]) environmental concern. A key factor of Sb mobility in soils is its redox state, which is closely related to soil aeration and Earthworm-produced calcium carbonate granules form a thus to the soil water regime. Under aerobic conditions, considerable proportion of soil carbonate and can be preserved thermodynamics predicts Sb to be stable as the pentavalent for up to ~2 Ma. They may play an important role in the - Sb(OH)6 , while under reducing conditions, the more toxic immobilisation of metals [1,2] and can be used to reconstruct

trivalent Sb(OH)3 predominates [1]. Both species strongly temperatures of the past [3]. The physiological function of differ in their affinity to iron (Fe) and manganese (Mn) these carbonates and their role in the terrestrial calcium and (hydr)oxides, which, in turn, may be reductively dissolved carbon cycles remain poorly understood. under reducing conditions. Experiments were performed with Lumbricus terrestris,

Here, we investigated how the interplay of reduction, one of the two main earthworm producers of CaCO3 granules sorption and dissolution processes affects Sb mobility in in many temperate soils. Earthworms were kept at different saturated soil subject to alternating redox conditions induced temperatures (3–20 °C) and, in a separate experiment, at

by autochthonous bacterial communities. Columns with Sb- different atmospheric CO2 levels (440–3800 ppm). Granule contaminated shooting range soil (pH 7.8) were eluted with 15 production rate was correlated with temperature (R2 = 0.55, p -1 mM sodium lactate solution for ~60 pore volumes (PV), < 0.0005) increasing from 0.8 to 2.7 mgCaCO3 earthworm interrupted by a 24 days stop-flow phase after 30 PV. With the day-1 between 3 and 20 °C. In contrast, granule production rate transition to reducing conditions, Sb(V) and Mn only showed a non-significant increasing trend under elevated

concentrations showed a concomitant increase, providing [CO2]. evidence that sorbed Sb(V) was released by reductive In the variable temperature experiment the stable carbon dissolution of Mn minerals. As reducing conditions continued, isotopic composition ('13C values) was measured for soils,

Sb was immobilized again by reduction of Sb(V) to Sb(III), food (manure), air, earthworm tissues, and CaCO3 granules. since the latter binds stronger to Fe (hydr)oxides at '13C values show that the majority of C in the granules comes circumneutral pH. However, as these Fe phases started to from the food offered to the earthworms. As such, '13C values dissolve with the onset of Fe-reducing conditions, the of granules originating from archaeological finds could be a previously bound Sb(III) was released back into the solution. useful proxy for vegetation type or agricultural practice Characteriztion of the solid phased by laser ablation (manuring) employed by past societies. In addition it suggests inductively coupled plasma-mass spectrometry (LA ICP-MS) that earthworms are converting carbon from a more labile underpinned the important role of Mn and Fe (hydr)oxides as organic-hosted form to a less labile mineral-hosted form. Sb sorbents. Our study shows for the first time that Sb can be [1] Brinza et al (2013) GCA, 10.1016/j.gca.2013.03.011; [2] mobilized under reducing conditions in soil also in form of Fraser et al (2011) GCA 75, 2544–2556, Sb(V) with the dissolution of Mn and thus provides further 10.1016/j.gca.2011.02.015; [3] Versteegh et al (submitted). reason for concern that release of Sb from insufficiently [3] Versteegh et al (2013) 10.1016/j.gca.2013.06.020 drained contaminated soil may pose a significant risk to the environment.

[1] Filella, Belzile & Chen (2002), Earth-Sci. Rev. 57, 125 - 176.

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Geochronology of the Lithospheric Fe3+ determination in garnet: Mantle underneath the A crystal chemical test with the Kimberlite Field, Namibia EPMA flank method C.E. HOEFER1,2*, G.P. BREY1, T. LUCHS1, A. GERDES1, H.E. HOEFER1*, C.E. HOEFER1, V. MATJUSCHKIN1, H.E. HOEFER1 G.M. YAXLEY2 AND G.P. BREY1 1Institut für Geowissenschaften, Goethe-Universität, 1Institut für Geowissenchaften, Goethe-Universität, Altenhöferallee 1, D-60438 Frankfurt, Germany; Altenhöferallee 1, 60438 Frankfurt am Main, Germany 2Institut für Geochemie und Petrologie, ETH-Zürich, (*[email protected],) Clausiusstrasse 25, CH-8092 Zürich, Switzerland 2Australian National University, Canberra, Australia (*[email protected]) We established the „flank method“ for in situ Recent comparative work has shown that differences and determination of garnet iron oxidation state with the electron similarities exist between the mantle underneath the Archean microprobe at micron-scale spatial resolution [1]. Besides the Kaapvaal craton and the attached Proterozoic terranes [1]. high spatial resolution, the great advantage of this method is Differences are: higher average in olivines from the the ability to analyse simultaneously the major element Kaapvaal craton, lower Al2O3 and CaO in their bulk rocks, Re chemistry on the same spot. depletion ages mostly older than 2.5 Ga and a thicker The flank method has been calibrated with a large number lithosphere. Similarities are: similar geothermal gradients, an of synthetic and natural garnets. We apply it here for the first overabundance of orthopyroxene in part of the mantle samples time, to garnets with grain sizes of 10-15 µm. They were and the existence of garnets with sigmoidal REE patterns. Re synthesized at various oxygen fugacities at high pressures. We depletion ages are all younger than 2.2 Ga [2]. determined Fe3+/%Fe together with the major element The 70 Ma old Gibeon Kimberlite Province is located in composition. Namibia within the mixed age Rehoboth Terrane (0.9-1.2 and The test for the reliability of the Fe3+/%Fe determined with 1.8-2.1 Ga). Three major localities with mantle xenoliths are the flank method uses a crystal chemical approach i.e. is based known: Hanaus, Gibeon Townsland and Louwrensia. Luchs et on constraints from the structural formula. In garnet with 2+ 3+ al [3] distinguished for Hanaus and Gibeon Townsland two general formula A 3B 2Si3O12 , the number of trivalent types of garnet peridotites by their REE patterns: i) peridotites cations on the octahedral B site is 2. A linear correlation of with flat middle to heavy REE in their garnets and ii) a minor Fe3+ per formula unit and the sum of further trivalent cations proportion with sinusoidal REE patterns as they are known plus Ti4+ must therefore exist. This is the case for the synthetic from the Kaapvaal craton. Bulk rock isotope trace element and high-pressure garnets of this study (Fig. 1). The excellent isotope compositions were calculated from the analysis of correlation is independent proof of the high quality of garnet garnets and clinopyroxenes and their modal abundances. A Fe3+ data determined using the flank method. Lu-Hf isochron for the peridotites with the sinusoidal REE patterns gave 1852 Ma as the age of enrichment of a previously strongly depleted mantle ("Hf = 29). The garnet peridotites with the flat middle to heavy REE patterns yielded a Lu-Hf age of 810 Ma with "Hf = 3.3. These ages overlap with crustal ages of the mixed age Rehoboth Terrane. We have extended our studies to samples from the Louwrensia kimberlite pipe and find a similar division as in Hanaus and Gibeon Townsland for the garnet peridotites. First results from isotope studies yield a Lu-Hf age of 1100 Ma which is within the age range of the adjoining Namaqua-Natal belt. Different mantle portions with ages reflecting different events seem to be hoisted to the Earth’s surface by the Gibeon kimberlites. The grt-cpx Lu-Hf two-point isochron ages give an alignment Figure 1: Fe3+ determined by the flank method versus the total of increasing age with decreasing temperatures between 1000 of the remaining cations on the octahedral site. to 1200 °C. We interpret these ages as cooling ages. Since kimberlite eruption ages are obtained for some samples at [1] Hoefer & Brey (2007) Am. Mineral. 92, 873-885. 1200 °C we conclude that the closure temperature for the Lu- Hf system must lie around that temperature for peridotite systems.

[1] Bell et al, Lithos, 2003; [2] Pearson et al, Chem. Geol., 2004; [3] Luchs et al, Precambrian Research, 2013, in press

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Zircon U-Pb, Lu-Hf and REE Preparation of micrometer sized soil Composition of Sorocaba and São particles for NanoSIMS analysis Francisco Granites, São Paulo State, C. HOESCHEN1*, T. HOESCHEN2, C.W. MUELLER1, SE Brazil T. RENNERT1, J. LUGMEIER1 AND I. KÖGEL-KNABNER1,3 1 1 1 Lehrstuhl für Bodenkunde, Technische Universität München, TABATA HOEGER LUQUE * AND SILVIO R.F. VLACH 85350 Freising-Weihenstephan, Germany 1IGc-USP,04280-000 , Brazil.*correspondence: (*correspondence: [email protected]) [tabatahl,srfvlach]@usp.br 2 Max-Planck-Institut für Plasmaphysik, EURATOM Association, 85748 Garching, Germany The granitic massifs of Sorocaba (SG, 180 km2) and São 3 Institute for Advanced Study, Technische Universität Francisco (SFG, 150 km2) are located southeast of São Paulo München, Lichtenbergstraße 2a, 85748 Garching, State, southeastern Brazil. They crop out near the Paraná Germany Basin and intrude low-grade meta-vulcano-sedimentary rocks. SHRIMP U-Pb ages, Lu-Hf (LA-MC-ICP-MS) isotopic data The study of biogeochemical interfaces in soils requires an and REE (LA-ICP-MS) abundances in zircon were considered adequate technique capable of revealing processes occurring at together with WR geochemistry (XRF and ICP-MS) to a sub-micron spatial scale. understand petrogenetic processes. NanoSIMS analysis provides information about The U-Pb ages for SG granodiorites are 617±4, 610±7 Ma, elemental/isotopic distributions at such a scale. Soil syeno- and monzogranites are 585±4 and 603±4 Ma. For the architecture is revealed by imaging the spatial distribution of SFG ages are 592±3 Ma for the syeno-monzogranites and organic matter (e.g.: 12C-, 12C14N- are detected) and mineral 599±4 Ma for the minor quartz-monzodiorites. constituents (e.g. 28Si-, 27Al16O-, 56Fe16O-). Lu-Hf isotope system from all the analyzed zircon crystals Samples relevant in soil science obtained by density display strongly negative "Hf0 values, compatible with crustal and/or particle size fractionation are usually single particles or signatures. The granodiorites "Hf0 values vary between -12.2 microaggregates with sizes in the micrometer range. Organic and -21.5. These values are slightly less evolved than those matter potentially distributed as a thin coating (few nm) on observed in the other samples; in the syeno- and mineral particles could be lost during the monzogranites from SG, "Hf0 are between -12.8 and -33.1. presputtering/implantation process before NanoSIMS Zircon crystals from quartz-monzodiorites of SFG displays measurement. The challenge is to prepare such primary "Hf0 between -30.5 and -33.5 varying in a more limited range, particles as flat, well-polished samples and to investigate them and the syeno-monzogranites "Hf0 varies between -32.5 and - in cross-section. Embedding in a carbon containing resin 54.4.3 results in ambiguities in distinguishing between the resin and 3REE patterns are characterized by negative Eu anomalies, the organic matter. variable positive Ce anomalies and variable enrichment of We present a method for preparing polished cross sections HREE regarding to MREE. The REE concentrations were of micrometer-sized primary soil particles. The particles were used to calculate partition coefficient data and then compared coated with a marker layer, embedded in epoxy resin and with the model from Blundy & Wood [1] considering: ro= Zr polished. In the cross section organic coatings and site in zircon, 0.84 Å [2]; Young’s modulus for Zr was assemblages on the primary soil particles can be distinguished. deducted from equation 15 [3]; Do= DZr and T= Zr saturation This method can essentially improve the quality of temperature in WR. The best-fit curves were those of the SFG NanoSIMS measurements on grainy mineral samples to better quartz-monzodiorites. Calculated partition coefficients of characterize soil biogeochemical interfaces. HREE show good correlation. Meanwhile, the LREE are slightly discrepant for the more felsic-studied rocks. Those discrepancies, joined with the other in situ analyses are a robust dataset that allow to analyse petrogenetic processes.

[1] Blundy, J. & Wood, B. (1994). Letters to Nature 372, 452– 454. [2] Shannon, R. D.(1976). Acta Crystallographica Section A 32, 751–767. [3] Wood, B. J. & Blundy, J. D. (2003) Treatise On Geochemistry, 2, chap 9, 395–424

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Archean mantle heterogeneities Chemical reactions at the air-water revealed by Hf-Nd isotope interface in the troposphere systematics of the 3.33 Ga MICHAEL R HOFFMANN*,, HIMANSHU MISHRA Commondale komatiites AND A. J. COLUSSI 1,2 3 Linde+Robinson Laboratory and Center for Global J. ELIS HOFFMANN AND ALLAN H. WILSON Environmental Science, California Institute of 1Universität zu Köln, Germany; [email protected] Technology, Pasadena, California 91125 USA 2Steinmann-Institut, Universität Bonn, Germany (*correspondence: [email protected]) 3University of Witwatersrand, Johannesburg, South Africa An in depth investigations of chemical and physical The modern Earth’s mantle is strongly heterogeneous, phenomena at air-water interface are critical for understanding bearing ancient depleted portions that escaped homo- heterogeneous processes on cloud droplets, dew, fog, and haze genization. For the Archean depleted mantle, the degree of aerosol. With this mind, the report that gas-phase isoprene (2- heterogenity is comparably unconstrained. Powerful tools to methyl buta-1,3-diene, ISO) is protonated as ISOH+ and + + investigate the degree of depletion of the mantle at a given oligomerized into a dimer, (ISO)2H , and a trimer, (ISO)3H , time are the radiogenic 176Lu-176Hf and 147Sm-143Nd decay during collisions with pH < 4 aqueous microdroplets during systems that can be applied on mafic and ultramafic rocks that gas-droplet collisions over 50 µs. Based on these observations, directly tapped depleted mantle sources. determined the probability of protonation per collision as 4 ~ Here we report the first ultra-depleted mantle reservoirs 10-5 corresponding to a process hindered by a 7 kcal mol- 1 for the Palaeoarchean tapped by the extraordinary well kinetic barrier. During the ' > 305 nm photolysis of H2O2 in

preserved 3.33 Ga Commandale komatiites [1] from the aqueous dilute ISO solutions yields C10H15OH species as eastern Kaapvaal Craton, South Africa. The best preserved primary products, whose formation both requires and is

samples yield identical Lu-Hf and Sm-Nd isochron ages of inhibited by O2. A minimum of seven C10H15OH isomers are 3334 ±27 Ma (MSWD: 0.21) and 3334 ±13 Ma (MSWD: resolved by reverse-phase high-performance liquid 0.76), respectively, also in agreement with the Re-Os chromatography and detected as MH+ (m/z = 153) and MH+- regression age of 3393 ±440 Ma [2]. Initial "Hf(t) and "Nd(t) 18 (m/z = 135) signals by electrospray ionization mass values are +6.5 to +9.2 and +1.6 to +2.4, revealing a spectrometry. decoupling of both isotope systems during previous melt extraction in the stability field of garnet. Moreover, a contamination with older crust during ascent can be excluded. In contrast, &Os(t) values are about chondritic, hence showing also decoupling from "Nd(t) and "Hf(t). This can be explained by the partition behaviour of Re-Os during mantle melting under oxidized conditions, leading to no fractionation of Re from Os in the source [3]. Primitive mantle normalized trace element patterns of the Commondale lavas show strong depletion of Nb-Ta, positive Zr-Hf, Ti and Y anomalies as well as comparably enriched LREE and Th for some samples. As alteration can be excluded here, the re-enrichment process might have been related to re-enrichment processes in an arc setting. This is supported by experimental data for the Commondale suite arguing for a hydrous mantle source [4]. Overall, the Commondale komatiites are the first reported strongly radiogenic Hf isotope compositions reported from the Palaeoarchean revealing initial "Hf(t) well above the average depleted mantle at 3.3 Ga.

[1] Wilson and Carlson (1989) EPSL 96, 89-105. [2] Wilson et al (2003) Nature, 423, 858-861. [3] Birck and Allègre (1994) EPSL 124, 139-148. [4] Barr et al (2009) EPSL 284, 199-207.

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Canonical trace element ratios and CD-MUSIC to interprete drifting partitioning during global primary charge of ferrihydrite differentiation A. HOFMANN1, T. HIEMSTRA2 AND J. LÜTZENKIRCHEN3 A.W. HOFMANN12* 1Géosystèmes UMR 8217, Université Lille 1, 59655 1 Villeneuve d’Ascq, France LDEO, Columbia University, Palisades, NY 10964, USA 2 Dept. Soil Quality, Wageningen University, 6700 AA 2Max Planck Institute for Chemistry, 55020 Mainz, Germany Wageningen, The Netherlands (*correspondence: [email protected]) 3INE, Karlsruher Institut für Technologie, 76344 Eggenstein-

Leopoldshafen, Germany For the past 16 years, the concept of “canonical” trace

element ratios - concentration ratios that do not systematically In recent years, « environmental minerals », especially change during global magmatic differentiation processes - has nanoparticles, have come into the focus of research because been variously questioned, declared invalid (e.g. [1]), or their short order structure confers them high chemical reaffirmed by many geochemical studies on oceanic basalts. reactivity. Many of these minerals are formed in Partitioning of such element pairs is sufficiently similar so that heterogeneous soil/water systems under ambient conditions. their ratios in melts reflect those of the source. Like isotope They reflect transitional, metastable phases that ultimately ratios, they are useful as tracers of mantle source composition, convert to thermodynamically stable phases, although this but they can be more diagnostic of global differentiation process can take very long periods of time. We will focus on processes than the parent-daughter pairs of long-lived surface complexation modeling and show how CD-MUSIC radioactive decay systems. Thus, Pb is partitioned similarly to can contribute to understanding dynamic phase the moderately incompatible LREE during intra-oceanic transformations. mantle melting, but it is highly incompatible (similar to U) When 2-line ferrihydrite is synthesized under during arc magmatism leading ultimately to formation of « environmental conditions », i.e. relatively low ionic strength, continental crust. Thus, although Pb isotopes do not no desalination and no drying steps, a material is formed distinguish well between continental and mantle sources, which is marked by drifting of the primary charge over time Pb/Ce ratios are sensitive discriminators. However, the basis and blurring of the point of zero salt effect. for using Pb/Ce as a diagnostic ratio has been criticized, in Modeling these data with CD-MUSIC suggests that the part because Pb has similar ionic properties as Sr, which is affinity of electrolyte ions changes during aging of the primary strongly affected by gabbroic plagioclase fractionation, so that material and that aggregational growth plays a role. We show primary Pb/Ce ratios should be sufficiently modified to that the particles’ surfaces reflect the subtle changes occurring invalidate Pb/Ce as a tracer of mantle composition. in the bulk material. Surface complexation modeling helps to I use recent, comprehensive, high-quality data on the decipher them, while classical spectroscopic and X-ray means composition of global ocean floor basalts [2, 3, 4] to reassess hardly can. canonical ratios involving Pb, Nb, Ta, K, U and other trace

elements relevant to global differentiation processes. Plagioclase fractionation affects Pb/Ce ratios remarkably little, presumably due to the presence of sulfide during gabbroic fractionation. Overall, the bulk partition coefficient D(Pb) is between the values for Ce and Pr . D(K) is between Ta and La, and D(Nb) between Th and U. The bulk terrestrial K/U ratio is not well defined by MORB data, because K/U varies with absolute trace element enrichment [2].

[1] Sims & DePaolo (1997) Geochim. Cosmochim. Acta 61, 765-784. [2] Arevalo & McDonough (2010) Chem. Geol. 217, 70-85. [3] Jenner & O’Neill (2012) Geochem. Geophys. Geosyst. 13, doi 10.1029/2011gc004009. [4] Gale et al (2013) Geochem. Geophys. Geosyst. 14, doi 10.1029/2012GC004334.

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Interaction of Eu(III) with calcite Using compound-specific isotope surfaces in presence of NaNO3 analysis to assess biodegradation of S. HOFMANN1* AND T. STUMPF 2 nitroaromatic explosives in the 1Karlsruhe Inst. of Techn., Inst. for Nuclear Waste Disposal subsurface (KIT-INE), Eggenstein-Leopoldshafen, Germany 1,2 1,2 RETO S. WIJKER , JAKOV BOLOTIN , (*correspondence: [email protected]) 3 3 2 SHIRLEY F. NISHINO , JIM C. SPAIN , KIT-INE, Eggenstein-Leopoldshafen, Germany 1,2 AND THOMAS B. HOFSTETTER *

Calcite is one of the most abundant minerals in the earth’s 1Eawag, Environmental Chemistry, CH-8600 Dübendorf, crust, playing an important role as a geochemical barrier in Switzerland, *[email protected] nuclear waste deposits. It is known to adsorb and even 2Institute of Biogeochemistry and Pollutant Dynamics, ETH incoporate many metal ions including lanthanides and Zürich, CH-8092 Zürich, Switzerland actinides [1, 2]. In this study, we present the influence of 3School of Civil & Environmental Engineering, Georgia

NaNO3 on the calcite surface and the uptake of Eu(III), Institute of Technology, Atlanta, GA 30332, USA investigated by site-selective time resolved laser fluorescence spectroscopy (TRLFS) and atomic force microscopy (AFM). Assessing the fate of nitroaromatic explosives in soils and Discussion of results sediments is challenging because these contaminants are TRLFS measurements with Eu(III) as a molecular probe present in different phases, that is bound to the organic and showed that the lanthanide ion is not incorporated into the mineral matrix or as solid-phase residues, and transformation calcite crystal itself. Excitation and emission spectra (Fig. 1) takes place via several competing pathways over time-scales differ considerably from the well-known Eu3+/calcite solid of decades. To infer the type and extent of biotransformation 3+ - solution [3]. The fluorescence lifetime of this Eu /NO3 of nitroaromatic compounds (NACs) from the combined /calcite species was determined to be 630 ± 50 µs, indicating evaluation of their C, N, and H isotope signatures, we have the presence of only one water molecule in the first developed procedures for compound-specific analysis of coordination shell of Eu. 2,4,6-trinitrotoluene (TNT), dinitrotoluene isomers (2,4-DNT and 2,6-DNT), and mono-nitrotoluenes in subsurface material from a contaminated site. Because of repeated spill events during decades of site operation as well as the perturbed subsurface at the study site, neither concentration nor !13C, !2H, or !15N profiles provided evidence for transformation. Correlation of N vs. C and H vs. C isotope fractionation, in contrast, enabled to the identification of three biodegradation routes. Indicative trends of $!15N vs. $!13C and $!2H vs. $!13C Figure 1: TRLFS excitation and emission spectra. were obtained from laboratory model systems with pure

cultures for reaction pathways initiated via (i) dioxygenation, For further characterization of the influence of NaNO3, calcite (ii) reduction, and (iii) CH3-group oxidation. The comparison single crystals were equilibrated in aqueous NaNO3 solutions 15 13 -7 -2 of $! N vs. $! C from field and laboratory data enabled a (10 to 10 M) and measured in situ with AFM. Images of distinction of reductive and oxidative transformation of TNT, these samples reveal critical changes of the surface 2,4-DNT, and 2,6-DNT while $!2H vs. $!13C was used to morphology (roughening of the facets and rounding of step quantify the relative shares of dioxygenation and CH -group edges). An amorphous, soft layer forms rapidly on top of the 3 oxidation. Based on the apparent kinetic isotope effects of the calcite lattice. Europium seems to be incorporated into this three biodegradation routes, our data imply that 86-89% of layer, which is about 0.8 ± 0.1 nm thick. 2,4-DNT transformation in the field was due to dioxygenation while TNT was mostly reduced to aminonitrotoluenes and 2,6-

[1] J. Paquette (1995), Geochim Cosmochim Ac, 59. [2] G. DNT reacted via a combination of reduction and CH3-group Aurelio (2010), Chem Geol, 270. [3] M. Schmidt (2008), oxidation. Isotopic and historic site information suggest Angew Chem Int Edit, 47. biodegradation of 2,4-DNT with half-lives of up to 9 to 17 years compared to 18 to 34 years for co-metabolic transformation of TNT and 2,6-DNT.

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Multi-proxy study of shallow- and Decay constants for dating deep-water Doushantuo carbonates, NORMAN E. HOLDEN1 Yangtze Platform, South China 1National Nuclear Data Center, Brookhaven National 1 1 1 2 Laboratory, Upton, New York 11973-5000, USA S.V. HOHL , H. BECKER , S. HERZLIEB , Q. GUO 3 AND A. GAMPER Two generations ago, the International Union of 1Freie Univ. Berlin, Germany, [email protected] Geological Sciences (IUGS), through a sub-committee, 2Institute of Geographic Sciences and Natural Resources recommended values for reporting isotopic data. A quarter Research, Chinese Academy of Sciences, Beijing 100101, century ago, the International Union of Pure and Applied China Chemistry (IUPAC) recommended values for half-lives (decay 3Museum für Naturkunde, Berlin, Germany constants) for a series of long-lived nuclides, many of which could be used for dating materials. The IUGS and the IUPAC The wide distribution of shallow and deep-water recommendations differed in many cases. More than a decade sedimentary facies has established the Yangtze Platform in ago, geochronologists began writing articles suggesting that South China as a key site for the study of ocean oxidation and updates should be made to the original IUGS Ediacaran animal evolution following the Marinoan glaciation. recommendations because of the existence of more recent data We have studied mineralogy, textures, major and trace on the original isotopic information that had been presented elements and Sr-C-O isotopic compositions of carbonates of and because of the absence of any uncertainties that were the Doushantuo formation from shallow- (Xiaofenghe, Hubei associated with that data. Province) and deep-water (Yanwutan, Hunan Province) A few years ago, an inter-Union Task Group of members sections in order to distinguish diagenetic overprint from of IUGS and IUPAC was formed to make ‘Recommendations primary signatures and to constrain compositional variations for Isotopic Data in the Geosciences’ and was approved by of Ediacaran seawater in space and time. Carbonate rocks their Executive Boards. The rationale was similar, there were from the lower part of Yanwutan section show elevated new data now available and the associated uncertainties need 87Sr/86Sr (0.7099 to 0.7220) and high Mn/Sr. Negative to be added to all recommended values. 87 86 18 correlation of Sr/ Sr with $ Ocarb in the upper part of the The procedure for any recommendation of isotopic data section indicates meteoric fluid-rock interaction. At would involve a re-evaluation of the measurement uncertainty Xiaofenghe, 87Sr/86Sr in cap carbonates (D1) is near 0.713, budgets for each experiment, especially for the ‘type-B’ or dropping to seawater-like ratios upsection (0.7079 in D3). non-statistical uncertainties, before combining the overall REE+Y patterns of deep water slope facies carbonates at uncertainties and determining a recommended value. A Yanwutan reveal preservation of seawater signatures, cap number of isotopes will be discussed. carbonates show no Ce anomalies, but high Eu/Eu* (1.9) and enrichment in MREE, which, given the high 87Sr/86Sr, may reflect strong hydrothermal overprint. In contrast, the upper part of the section displays HREE enrichment, negative Ce, and variable positive Eu anomalies, indicating oxidizing conditions of deep water during this time interval. REE+Y patterns of carbonates at Xiaofenghe section are flat to

variable HREE enriched, with Y/HoPAAS (>2.1), indicating the presence of a seawater signature. While the cap carbonates have no Ce anomalies, D2 and D3 carbonates show strongly negative Ce anomalies, indicating precipitation from an oxidized water column. A main conclusion from the data is that deep water of the Yangtze basin was oxidized as early as the middle Doushantuo, with likely anoxic conditions before that time. Fluid-mobile elements in deepwater sections are more overprinted than in shallow water sections, presumably by hot reducing fluids of variable origin. Although fluid- mobile elements (Ba, Sr, Ca, Mg) commonly show evidence for modification by post-depositional fluid flow, REE+Y in these rocks often preserve seawater signals.

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Deep fracture fluids isolated in the Influence of different organic carbon crust since the Precambrian substrates on denitrification rates in G.HOLLAND1,2, B. SHERWOOD LOLLAR3, L. LI3, riparian sediment 3 4 G. LACRAMPE-COULOUME , G.F. SLATER 1 1,2 1 MELISA HOLLINGHAM *, RAOUL-MARIE COUTURE , AND C.J. BALLENTINE * 1 FEREIDOUN REZANEZHAD 1 SEAES, Manchester University, Manchester M13 9PL UK AND PHILIPPE VAN CAPPELLEN 1 2LEC, University, Lancaster LA1 4YQ UK 1University of Waterloo, Waterloo, Ontario, Canada, 3Dept. of Earth Sciences, University of Toronto, ON, Canada (*correspondence: [email protected]) M5S 3B1 2 Norwegian Institute for Water Research, Oslo, Norway 4SGG, McMaster University, Hamilton ON Canada L8S 4K1

- Nitrate (NO ) is an ubiquitous groundwater contaminant Water bearing macrosystems that have been isolated from 3 in agricultural and wastewater discharge areas [1]. The the surface and preserved on geological timescales (>10Ma) - prediction of microbially mediated NO removal in subsurface are seemingly rare. Nevertheless, the unique insight they 3 environments requires an understanding of the rates at which provide into the evolution of chemolithotrophic life makes electron donors are utilized by denitrifying microbes [2]. This these systems important areas of study. The Witwatersrand study focuses specifically on the following organic carbon Basin in the South African Precambrian Crystalline Shield compounds as electron donors: glucose, acetate, adenine, provides the case type [1,2]. Here, we have determined the cysteine and fulvic acid. Six triplicate series of flow through noble gas concentration and isotopic composition of 6 gas reactors (FTRs) containing 35cm3 of natural, organic-poor, samples, co-produced with water, from deep exploratory riparian sediment were supplied for 10 weeks with solutions boreholes in a producing mine in the Timmins region of the containing nitrate and the individual carbon compounds, along Canadian Precambrian Crystalline Shield. with a no-carbon added control. The organic carbon We show that 124,126,128Xe excesses in the Timmins mine compounds were selected to yield a range of Gibbs Free fluids can be linked to Xe isotope changes in the ancient Energy ($G) values when their oxidation is coupled to atmosphere [3] and can be used to calculate a minimum mean denitrification. The initial flow rate of the FTRs was 1 ml h-1. residence time for this fluid of ~1.5Ga. We also resolve in all - 129 Once steady NO3 concentrations were reached in the outflow, samples a clear Xe signal in excess of atmospheric values. -1 the flow rate was increased to 2 ml h and, subsequently, 4 ml Mass fractionation and U fission can be excluded as sources of h-1. Maximum potential denitrification rates (R ) measured 129Xe, and a mantle source is unlikely. We postulate 129Xe is max for the different carbon substrates spanned an order of sourced in carbon rich metamorphic material of sedimentary -3 -1 magnitude, ranging from 0 to 91nmol cm h . Fulvic acid did origin and extracted by fluid migration processes at ~2.64Ga. not induce denitrification, while acetate yielded the highest Neon isotopic compositions are similar to the Witwatersrand rate. The outflow solutions for FTRs supplied with adenine study and are used to validate the closed system assumption and cysteine contained ammonia and sulfate, respectively. for the radiogenic noble gases [1]. Closed system radiogenic These results are consistent with the structure of the organic noble gas residence times are 1142±64,5 1655±789, components of adenine, containing an amine, and cysteine, 1498±784, 1610±825Ma for 4He, 21Ne, 40Ar, 136Xe containing a thiol group. R values for the studied carbon respectively. Combined together, these complementary strands max substrates are relatively low compared to those in the literature of evidence lend further support to the hypothesis that ancient for similar experiments, which have values ranging from 98 to pockets of water can survive the crustal fracturing process and -3 -1 933 nmol cm h [3]. Most likely, the low rates reflect a low remain in the crust for billions of years [4]. abundance of denitrifying organisms in the riparian sediment

used. [1] Lippmann-Pipke et al (2011) Chem. Geol. 283, 287-296. [2] Lin et al (2006) Science 314, 479-482. [3] Pujol, M. et al, (2011). Earth Planet. Sci. Lett. 308, 298-306. [4] Holland et [1] Xue et al (2009) Water Research 43 1159-1170. al, (2013) Nature, in press. [2] Thullner et al (2007) Geomicrobiol. J. 24 139-155. [3] Laverman et al (2006) FEMS Microbiol Ecol 58 179-192

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Tectonic evolution of the Cerro Natural Cu-Al-Fe metallic Casale Cu-porphyry system, Chile: in the new CV3 Implications for mineralisation , Khatyrka PETE HOLLINGS1*, HUAYONG CHEN2,3 L. HOLLISTER*, C. ANDRONICOS2, L. BINDI3, AND DAVID R. COOKE2 V. DISTLER4, M. EDDY5, J. EILER 6, Y. GUAN6, 7 4 8 1 A. KOSTIN , V. KRYACHKO , G. MACPHERSON , Dept. of Geology, Lakehead University, Thunder Bay, W. STEINHARDT9, M. YUDOVSKAYA4 Ontario, Canada, P7B5E1. (*correspondence: AND P. STEINHARDT10 [email protected]) 2CODES, ARC Centre for Excellence in Ore Deposits, Private *Princeton University, Princeton, NJ 08544, USA Bag 126, Hobart, Tasmania 7001, Australia (correspondence: [email protected]); 3Guangzhou Institute of Geochemistry, Chinese Academy of 2Purdue University, West Lafayette, IN; Sciences, Tianhe, PO Box 1131, Guangzhou, China 3Università di Firenze, Florence, Italy; "" 4Russian Academy of Sciences, Moscow, Russia The Cerro Casale porphyry Cu-Au deposit is located at the 5Massachusetts Institute of Technology, Cambridge, MA; southern end of the Maricunga belt, near the northern 6Caltech, Pasadena, CA, 7BHP Billiton, Houston, TX; boundary of the modern nonvolcanic, flat-slab region of the 8Smithsonian Institution, Washington, D.C. Chilean Andes (28-33oS). Oligocene andesitic volcanic rocks 9Harvard University, Cambridge, MA in the Casale district have been intruded by the Cerro Casale, 10Dept. of Physics, Princeton University, Princeton, NJ 08544. Roman, Eva, Estrella and Anfiteatro dioritic to granodioritic plutons, of which the Casale diorite is the main host to Khatyrka occurs as clastic grains within clay-rich layers mineralisation (1300 Mt @ 0.7 g/t Au and 0.35% Cu). along the banks of a small stream in the Koryak Mountains of U-Pb dating of zircon from the mineralized granodiorite far eastern Russia. The recovered grains share in common the yielded an age of 13.9 ± 1.1 Ma, consistent with previous Ar- presence of metallic Cu-Al-Fe alloys that include the

Ar ages of 13.89 - 13.91 Ma from hydrothermal biotite and quasicrystalline phase (Al63Cu24Fe13), along with

alunite [1]. Weakly mineralised to barren intrusions in the (CuAl2) and (CuAl). Some of the ~ mm- district range in age from 28 to 14 Ma, with a major sized meteorite grains clearly are CV3 (oxidized) chondrite porphyry-high sulfidation system forming at the Caspiche fragments having Type IA porphyritic olivine chondrules prospect ~10 km to the north in the late Oligocene, implying enclosed in matrices that have the characteristic platy olivine repeated mineralising episodes in the region. texture, matrix olivine composition, and mineralogy of The volcanic and intrusive rocks from the Casale district oxidized-subgroup CV3 chondrites. Other grains are fine- are predominantly medium-K andesites and diorites. The grained spinel-rich calcium-aluminum-rich inclusions (CAIs) 17 intrusive rocks show a trend to increasing Gd/Ybn ratios in with spinel oxygen isotopic compositions (( O ~ -19 – -23 younger samples comparable to trends in Miocene rocks ‰) typical of such objects in CV3 chondrites. One grain is an related to porphyry mineralisation in Central Chile interpreted achondritic intergrowth of Cu-Al-Fe metal alloys with to be the result of subduction of the Juan Fernandez ridge and forsteritic olivine ± diopsidic pyroxene. The latter, along with 16 17 associated slab flattening [2]. "Nd values for the intrusive rocks silicates from the chondritic grains, have O-enriched (( O ~ are uniformly negative (-0.6 to -2.8), consistent with -4 – -8 ‰) oxygen isotopic compositions that plot on the contamination by older crustal sources, and show a weak trend CCAM mixing line in the region occupied by bulk CV3 87 86 to less negative values with time. Sr/ Sri values range from chondrites [1, 2]. Finally, some grains consist almost entirely 0.70490 to 0.70547 and increase in younger intrusions. The of Cu-Al-Fe alloys The Cu-Al-Fe metal alloys and the -

less negative "Nd in the younger intrusions in conjunction with bearing clast are either a unique accretionary a slight increase in Ni contents suggests a more primitive component of what otherwise is a fairly normal CV3 source for the mineralising magmas. (oxidized) chondrite, or else formed in place via an as-yet undetermined process. Either way, the reducing conditions [1] Muntean, J.L., and Einaudi, M.T. (2000), Economic required to form such metallic aluminum-bearing alloys are Geology 95, 1445-1472. [2] Hollings, P., Cooke, D.R., and approximately those of a hot gas of solar composition. Clark, A. (2005), Economic Geology 100, 887-904. Understanding what specific process(es) formed these alloys of two such cosmochemically-dissimilar elements as aluminum and copper remains the focus of our on-going research program.

[1] Bindi, L. et al (2012) PNAS, 109: 1396-1401; [2] MacPherson, G. et al (2013) MAPS (submitted).

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Fe(II) in early abiotic processes Compositional constraints on the NILS G. HOLM mantle below part of the Andes SVZ Department of Geological Sciences, Stockholm University, P.M. HOLM1*, N. SØAGER1 AND C.T. DYHR1 SE-106 91 Stockholm, Sweden; ([email protected]) 1 Institute of Geosciences and Natural Resource Management,

Univ. Copenhagen, Ø. Voldgade 10, DK-1350 Recently, it was suggested that Fe(II) preceded Mg(II) as Copenhagen, Denmark an efficient co-factor in prebiotic catalysts on the early Earth (*correspondence: [email protected]) [1]. Mg(II) has a special role in the folding and catalysis of biomolecules such as RNA because of its small size and This contribution discusses along and across arc ability to coordinate six oxygen atoms, including in differences in Pleictocene-Recent volcanic rocks of the SVZ oxyanions, in its first coordination shell [2]. In principle, based on new major and trace element and Sr, Nd and Pb Fe(II) can replace Mg(II) in this function and be even more isotope data from the T- and N-SVZ. We limit our discussion efficient [1], but on Earth today Fe(II) is quickly oxidized to to little evolved compositions with high Mg#. Dispite their Fe(III) in the presence of molecular oxygen. However, before primitive character most of these arc magmas display a strong the Great Oxidation Event about 2.5 Ga Fe(II) would have negative correlation between silica and Ba/Th. Relative HFS- been abundant in aqueous systems. Iron metabolism in modern depletion is not caused by residual rutile is demonstrated by organisms is controlled by small RNAs molecules (sRNA) [3]. La-Nb systematics. Therefore, the relative enrichment in Because of the ability of Fe(II) to coordinate oxyanions, Fe(II) LILEs and LREEs is a reflection of source compostion and minerals can catalyze the formation of pyrophosphate from show that that continental material with e.g. low Ba/Th rather activated phosphate compounds, such as acetyl phosphate, and than fluid was added to a source. The pre-enrichment mantle inorganic phosphate [4]. It has also been found, that even was more depleted in the C-NVZ than in the more northern T- though modern deep-sea water is oxidized, Fe(II) originating and N-SVZ. Furthermore, all mantle below the arc is distinctly in hydrothermal fluids are stabilized because of its affinity to more depleted than the back-arc mantle, and compositional lipids, polysaccharides and proteins [5]. Abiotic formation of variation is thus indicated both N-S and E-W. Isotopically the acetyl phosphate has been reported. It is, therefore, likely that depleted end-member is comparable to South Atlantic MORB Fe(II) would have been a powerful component in the mantle. Two distinctly different isotopically enriched formation of pre-RNA types of information molecules in early endmembers show a similar elemental crustal signature. A Pb, life systems. Sr and Nd isotopic array of the northern backarc to T-SVZ arc

magmas allow the arc-backarc mantle to be identified as [1] Athavale, Petrov, Hsiao, Watkins, Prickett, Gossett, Lie, distinct from the upwelling enriched Río Colorado component Bowman, O’Neill, Bernier, Hud, Wartell, Harvey & Williams (Søager et al, in prep.). There is a general decrease in water (2012), PLoS One 7(5). [2] Holm (2012), Geobiology 10, soluble components away from the trench. This may indicate 269-279. [3] Massé, Salvail, Desnoyers & Arguin (2007), that the fluid enriched source is generated over a more shallow Current Opinion in Microbiology 10, 140-145. [4] de Zwart, part of the subducting slab than the crust enriched source. We Meade & Pratt (2004), Geochimica et Cosmochimica Acta 68, model the crustal component that is added to the source as 4093-4098. [5] Toner, Fakra, Manganini, Santelli, Marcus, Moffett, Rouxel, German & Edwards (2009), Nature melts of subduction eroded continental crust that reacted with the overlying mantle. Geoscience 2, 197-201.

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Tracing the rise of atmospheric The Hf-W chronology of FUN CAIs oxygen using Cr isotopes in J. C. HOLST1, M.B. OLSEN1, C. PATON1, carbonates as a paleoredox proxy K. NAGASHIMA2, M. SCHILLER1, D. WIELANDT1, K.K. LARSEN1, J. N. CONNELLY1, J. K. JØRGENSEN1, 1 2 C. HOLMDEN AND A.D. BEKKER A.N. KROT1,2, Å. NORDLUND1 AND M. BIZZARRO 1 1Saskatchewan Isotope Laboratory, Department of Geological 1Centre for Star and Planet Formation, University of Sciences, University of Saskatchewan, SK, S7N 5E2 Copenhagen, Copenhagen, Denmark. CANADA (*correspondence: [email protected]) 2Institute of Geophysics and Planetology, University of 2Department of Geological Sciences, University of Manitoba, Hawaii at Manoa, HI 96822, USA MB, SK R3T 2N2 CANADA ([email protected]) Refractory inclusions (CAIs) represent the oldest solar The Great Oxidation Event (GOE) is now well- system solids and provide information regarding the formation constrained in age to ca. 2.4–2.3 Ga, but questions remain of the Sun and its protoplanetary disk. CAIs contain evidence whether the pathway to oxidized surface environments was of now extinct short-lived radioisotopes synthesized in one or gradual, oscillatory with transient oxidation events, or multiple stars and added to the protosolar molecular cloud stepwise. Various proxies, including fractionation of Cr before or during its collapse. Understanding the origin of isotopes in iron formations (Frei et al, 2009), have been used short-lived radioisotopes is necessary to assess their validity as to infer, at least locally, the development of oxidizing chronometers and constrain the birthplace of the Sun. Whereas conditions as early as 2.7 Ga. Alternatively, Konhauser et al most CAIs formed with the canonical abundance of 26Al (2011) argued that Cr concentrations were low in iron corresponding to 26Al/27Al of !5!10"5, rare CAIs with formations until 2.5-2.3 Ga when acidic formed fractionation and unidentified nuclear isotope effects (FUN in response to the GOE and delivered reduced Cr to shallow- CAIs) [1] record nucleosynthetic isotopic heterogeneity and water environments. 26Al/27Al of <5!10–6, possibly reflecting their formation before Here, we tested whether !53Cr values in shallow-water canonical CAIs [2]. Thus, FUN CAIs may provide a time- carbonates spanning the GOE might also record steps in the window into the earliest solar system, but their chronology is rise of atmospheric oxygen. Cr isotopes are fractionated by unknown. redox reactions such as those occuring during Mn-mediated Cr Using the 182Hf-182W chronometer, we show that a newly oxidation on the continents or Cr reduction in anoxic marine discovered FUN CAI, dubbed STP-1, formed coevally with environments. In the absence of molecular oxygen, the range canonical CAIs [3], but with 26Al/27Al of ~3!10–6. Moreover, of Cr isotope fractionation in exogenic materials would likely the mineralogy and the group II rare earth element (REE) be confined to the range of igneous rocks (!53Cr = –0.1 ± pattern coupled with a 16O-rich composition, suggest that the 0.1‰). Carbonates from 15 formations were chosen with precursor material of STP-1 formed by condensation from a depositonal ages ranging between 2.5 Ga and 1.9 Ga. gas of solar composition depleted in the most refractory REEs, Carbonate is more abundant than iron formation in the rock similar to fine-grained CAIs. The level of 26Al/27Al in STP-1 is record, but there are pitfalls with carbonate-hosted seawater higher than the galactic background and suggests that our Sun records that must be borne in mind. These include formed as part of a cloud that was chemically enriched by dolomitization, local cycling effects, depositional earlier generations of massive stars. The observed decoupling fractionation, and detrital sediment contamination. between 182Hf and 26Al requires distinct stellar origins: steady- !53Cr data collected, thus far, show no fractionation in state galactic stellar nucleosynthesis for 182Hf and late-stage samples older than 2.4 Ga, a very mild amount of fractionation contamination of the protosolar molecular cloud by a massive at ca. 2.3 Ga of ~0.1‰, and permil level fractionation at 2.15 star(s) for 26Al. Admixing of fresh stellar-derived 26Al to the Ga in the peak inerval of the Lomagundi carbon isotope protoplanetary disk occurred during the of CAI- excursion. Interestingly, the fractionations are both positive formation and, therefore, the 26Al-26Mg systematics of CAIs and negative relative to !53Cr in igneous rocks. Although cannot be used to define their formation interval. In contrast, fractionated Cr may be hosted in both carbonate and lithogenic our results support 182Hf homogeneity and the chronological components, Cr/Al ratios support the predominantly significance of the 182Hf-182W clock. authigenic origin of the Cr in the carbonate fraction. These data are consistent with acidic weathering at the beginning of [1] Wasserburg et al (1977) Geophys Res Lett 4, 299. [2] the GOE and Mn-mediated Cr oxidation during the Sahijpal & Goswami (1998) Astrophys. J. 509, L137-L140. Lomagundi carbon isotope excursion. [3] Burkhardt et al (2012) Astrophys. J. 753, L6.

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Microbially-induced carbonate Trace metal inputs from river-fed precipitation, Moodies Group and river-starved margin sediments (3.2 Ga, BGB, South Africa) of the South Atlantic Ocean 1 1 1 2 1 1 M. HOMANN *, C. HEUBECK , A. AIRO , M. TICE AND WILLIAM B. HOMOKY *, RACHEL A. MILLS , YU-TE S. NABHAN1 HSIEH2,3, DEBORAH J. HEMBURY1, E. MALCOLM S. 4 2 1 WOODWARD AND GIDEON M. HENDERSON Freie Universität Berlin, Institute of Geological Sciences, Malteserstr. 74-100, 1Ocean and Earth Science, National Oceanography Centre 12249 Berlin, Germany (*correspondence: Southampton, University of Southampton, SO14 3ZH, [email protected]) UK (*Correspondence: [email protected], 2Texas A&M University, College Station, Texas 77843, USA [email protected], [email protected]) ([email protected]) 2Department of Earth Sciences, Univeristy of Oxford, South Parks Road, OX1 3AN, UK ([email protected]) The Archean Moodies Group, Barberton Greenstone Belt 3Program of Atmosphere, Ocean and Climate, Massachusetts (BGB), ~3.2 Ga, represents Earth's oldest known tidally Institute of Technology, 77 Massachusetts Avenue, influenced siliciclastic sequence and includes well-preserved Cambridge, MA 02139, USA ([email protected]) microbial mats which can be traced laterally for >15 km. 4Plymouth Marine Laboratory, Prospect Place, The Hoe, We investigated the microstructure of crinkly intertidal- Plymouth, PL1 3DH ([email protected]) facies mat morphotypes and tufted supratidal-facies mats, both preserved as abundant kerogenous laminae ~1mm thick Trace metal exchange between sediments and seawater overlying individual depositional events in medium- to coarse- may play an important role in providing micronutrients to the grained sandstones. Mats are widely underlain by up to 40 cm ocean. Continental margin fluxes of metals such as Fe remain long and few mm-thick monomineralic layers; microbial tufts poorly constrained but may be important in the global carbon (1-2 cm in height) show increased calcification within their cycle [1]. A selection of micronutrient trace metals have been interior. XRF elemental scanning of fresh slabbed and measured in porewaters and sediments from the slopes on both polished handsamples indicates (1) that the monomineralic sides of the South Atlantic Ocean to determine such margin layers underlying the microbial mats consist of pure carbonate fluxes to a region of high primary productivity in the surface (calcite, dolomite), now largely replaced by microcrystalline ocean. Intact surface sediments were collected by coring quartz, and that (2) Fe is enriched in the kerogenous mat activities on two UK GEOTRACES expeditions (D357 and remnants. SEM observations of freshly exposed kerogenous JC068; GA10) from 12 sites between the River Plate-fed surfaces show interwoven, bundled and twisted filaments 1-3 Uruguyan margin and the comparatively river-starved Cape µm in diameter, confirming mat biogenicity. margin of South Africa. The close association of carbonate layers and microbial Macronutrient and micronutrient concentrations are mats suggests that mat metabolic activity promoted their principally coupled to organic carbon oxidation at all sites. Fe

formation. An autotrophic metabolism, such as CO2 fixation, and Mn inputs to the South Atlantic are calculated from the would have increased the alkalinity of the pore fluid beneath relationship between porewater metal and high-resolution the mat and induced carbonate precipitation. Alternatively or oxygen data. Dissolved fluxes of Fe and Mn on the Uruguyan additionally, carbonate could have formed as a byproduct of a and South African margins have notable differences in their Fe-reducing metabolic pathway. Middle Archean photic-zone magnitude and down-slope distribution. We show the filamentous microbial mats may have, at least in its upper variability of metal supply reflects (a) enhanced organic layers, employed a photosynthetic strategy. carbon respiration on the river-fed Uruguyan margin, and (b) the depleted metal substrate reservoir on the comparatively river-starved Cape margin of South Africa. This study provides new constraints on dissolved micronutrient inputs to South Atlantic deep waters which subsequently upwell in the Fe-starved Southern Ocean. It also provides information about the general role of sediments in micronutrient fluxes to seawater.

[1] Boyd and Ellwood (2010) Nature Geoscience, 25(10), 675

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Diffusive fractionation of Abrupt variations of Indian and East isotopes in polycrystalline olivine Asian summer monsoons during the V HOMOLOVA* AND E B WATSON last deglacial stadial and interstadial Department of Earth and Environmental Sciences, Rensselaer B. HONG1), Y.T. HONG1, M. UCHIDA2, Y. SHIBATA2 Polytechnic Institute, Troy, NY 12180, USA AND Y.X. ZHU1 (*correspondence: [email protected]) 1 Institute of Geochemistry, Chinese Academy of Sciences,

Guiyang 550002, China ()correspondence: Diffusive fractionation of Li isotopes has recently been [email protected]) reported in silicate melts, aqueous fluids and single crystals [1, 2 National Institute for Environmental Studies, Onogawa 16-2, 2, 3]. Here, we present an experimental study which Tsukuba, Ibaraki 305-0053, Japan investigates diffusive fractionation of Li isotopes in polycrystalline olivine. The experimental procedure consists The recent study comparing marine and terrestrial of annealing oxide powders in an iron capsule at 1.4 GPa and palaeoclimate records from South Asia suggests that during 1250˚C for 48 hours. The annealing step produces a synthetic the deglaciation the ISM fluctuated widely, with weaker rock comprising olivine (Fo90) plus 15 wt% pyroxene (En92), monsoons during colder episodes, such as the Younger Dryas with grains 50 - 75um in diameter. The capsule is then (YD), and stronger monsoons during warmer episodes, such as sectioned, polished and juxtaposed to a spodumene powder, the Bølling-Allerød (BA) [1]. However, this study does not which acts as the Li source. The diffusion couples were held at cover the palaeoclimate records from some East Asian regions 1.4 GPa and 700 - 1000˚C for 12 - 120 hours. Li abundances influenced by the Indian Summer Monsoon (ISM), such as the and isotopic (7Li/6Li) profiles were analyzed using LA-ICP- Tibetan Plateau and its adjacent regions, and it does not MS. include the activity of the East Asian Summer Monsoon Maximum lithium abundances measured near the Li (EASM). Another study on global climate evolution during the source in the olivine and pyroxene reach ~550 and ~700 ppm, last deglaciation briefly discusses the behaviours of the ISM respectively. Li abundances decrease as a function of distance and EASM during the transient period and mainly focuses on from the source to the background Li concentration of ~3 the results of a few stalagmite 18O records from the southern ppm. Preliminary data suggest an effective diffusivity of Li in 2 Chinese mainland [2]. To complement these studies, we polycrystalline olivine plus pyroxene of ~5E-13m /s at the 13 present a continuous peat cellulose ' C record of ISM highest temperature investigated. In both olivine and covering the past 15000 years. By comparing this record with pyroxene, 7Li/6Li ratios decrease linearly or in a concave a variety of other monsoon proxy records, especially with the down fashion for the entirety of the diffusion profile before EASM proxy records published in recent years, we attempt to abruptly jumping back up to the initial isotopic ratio of the clarify the abrupt variation, phase relationship, and possible synthetic rock. This decrease in 7Li/6Li along the diffusion forcing mechanisms of two Asian monsoons during the last profile is similar to previous studies investigating diffusive deglaciation. fractionation of Li isotopes and suggests a higher diffusivity of

6Li relative to 7Li. The shape of the isotopic profile may be [1] Tiwari et al (2011) J Geol Res 1-12. [2] Clark et al (2012) replicated well with a model previously developed by [3] for PNAS 109, E1134-E1142. Li diffusion with reaction in single crystal olivine, in which Li simultaneously diffuses via two different mechanisms. Application of the data to diffusive transport of Li in the upper mantle will be discussed. Experiments at higher temperature and utilizing alternate Li sources are underway.

[1] Richter et al (2003) GCA 67 3905 - 3923 [2] Richter et al (2006) GCA 70 277 - 289 [3] Dohmen et al (2010) GCA 74 274 - 292

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Distribution, Fluxes in the water Redox behavior of uranium column and early diagenesis in the incorporated into hematite 210 210 bottom sediments of Po and Pb in DERRELL HOOD1, YI WEN1, the sea LINDSAY SHULLER-NICKLES*1 1 1 1 2 1 Clemson University, 342 Computer Court, Anderson, SC, G.H. HONG *, H.M.LEE , M. BASKARAN , S.H.KIM , 1 1 USA 29625 (*correspondence: [email protected]) Y.I.KIM AND C.J. KIM

1Korea Institute of Ocean Science and Technology,, Ansan The development of long-term geological waste 426-744, R. Korea (correspondence: [email protected]) repositories is an important response to ever increasing 2Wayne State University, Detroit, MI 48202, amounts of spent nuclear fuel. One of the principle U.S.A.([email protected]) considerations at any potential storage site is the possibility for radionuclides to leach from waste forms and undergo sub- The 210Po activity, granddaughter of 210Pb activity, has surface transport. The solubility of radionuclides in the been widely studied to elucidate various oceanic processes, repository environment, their redox behavior, and possible such as quantifying the scavenging and removal of particle- incorporation into proximal mineral phases are inter-related reactive species including organic matter. The deficit and mechanisms that synergistically affect the subsequent excess of 210Po with respect to its grandparent 210Pb in hydrological transport of the nuclides. dissolved and particulate phases in the surface ocean is well It has been shown that U(VI) can be incorporated into bulk documented through the ocean. However, in deep waters hematite with a similar coordination environment as Fe(III) below 1000 m, secular equilibrium between 210Po and 210Pb [1,2]. In this study, we analyze the incorporation of U(VI) was observed in some areas, but a large deficiency of 210Po into hematite as a possible mechanism of limiting the aqueous with respect to 210Pb in dissolved phase was also observed in uranyl concentration in contaminated areas. Atomistic several places in the world ocean. Recent efforts were made simulations were conducted to evaluate the incorporation extensively by GEOTRACES [1, 2] to resolve the unresolved mechanism (i.e., substitution reaction energies and substitution issues in determination of 210Po and 210Pb remaining from the geometries). The redox behavior of uranyl incorporated into earlier GEOSECS studies in late 1970s. He we report new bulk hematite was investigated using cyclic voltametry with a measurements of dissolved, particulate, and sediment powder microelectrode. In addition, the redox behavior of porewater 210Po and 210Pb in a deep marginal sea in the uranyl incorporated into hematite is compared with that of Northwest Pacific (East Sea/Japan Sea) using the state of the uranyl at the hematite surface to evaluate the role of hematite art measurement methods considering all relevant correction as a uranyl host and as a substrate for uranyl sorption, factors in the calculation of the final in situ their activities reduction and precipitation. provided by GEOTRACES 210Po/210Pb group. The earlier The sample was preconditioned for thirty minutes at discrepancy may be resolved as we can generalize the vertical "0.25V and scanned between ±0.7 V at a rate of 50 mV/s. distribution of dissolved 210Po with respect to dissolved 210Pb Under these conditions, uranyl was observed to undergo an in the sea as the surface deficit, subsurface excess and secular irreversible oxidation from U(IV) to U(VI) on the first positive equilibrium below the 500 m or 1000 m depth based on our voltage scan. Subsequent cycles indicate reduction and re- measurements with great variation of total activities due to oxidation between U(VI) and U(V). Similar experiments their variation in the sources as well as the amount of examined uranyl in solution with hematite and measured suspended particulate matter in the water column. An order of comparable uranyl redox behavior. Due to the strong relation magnitude greater concentration of dissolved 210Po and 210Pb between uranium solubility and oxidation state, these initial concentration activities were present in the interstitial waters results are significant with regards to potential aqueous uranyl of the bottom sediment with 210Po deficit or excess with immobilization. respect to 210Pb in the East Sea. Detailed quantitative analysis on the distribution, chemistry, flux, and early diagenesis be [1] Duff (2002) Geochimica Acta 20, 3533-3547 [2] Ilton presented at the meeting. (2012) Environmental Science and Technology 46, 9428-9436

[1] Church et al (2012). Limnol. Oceanog.: Methods 10, 776- 789. [2] Baskaran et al (2013). in press.

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Os isotope constraints on crustal Ancient thermal events on 4 Vesta contamination in Auckland Volcanic recorded in zircon U-Th-Pb-Ti depth Field basalts, New Zealand profiles from a brecciated eucrite

1 2 3 4 J.L. HOPKINS *, A. POIRIER ,M-A. MILLET , C. TIMM , M. D. HOPKINS1*,S. J. MOJZSIS1,2,4,W.F. BOTTKE3,4 4 1 G. LEONARD AND C.J.N. WILSON AND O. ABRAMOV5 1SGEES, Victoria University of Wellington, PO Box 600, 1 University of Colorado, Geol. Sciences, Boulder, CO USA Wellington, New Zealand. (*[email protected]) (*correspondence: [email protected]) 2 2 GEOTOP, Université du Québec à Montréal, Montréal, Laboratoire de Géologie de Lyon, ENS & UCBL1, France Canada 3 Southwest Research Institute, Boulder, CO, USA 3Origins Laboratory, Department of the Geophysical Sciences, 4 Center for Lunar Origin and Evolution, NLSI University of Chicago,USA 5 United States Geological Survey, Flagstaff, AZ, USA 4GNS Science, Lower Hutt, New Zealand Zircons in asteroidal meterorites are rare, but a modest Basalts from the monogenetic Auckland Volcanic Field number have been previously documented, including those in (AVF) have been inferred to derive from the partial melting the howardite-eucrite-diogenite (HED) achondrite group. The and mixing of varying proportions of three distinct HEDs probably originate from 4 Vesta. Sub-micrometer components from within two mantle sources: (a) ambient distributions of trace elements (Ti, U, Th) and 235,238U-207,206Pb asthenospheric mantle consisting of mid ocean ridge-like ages were investigated in four zircons (>7-40 µm *) separated peridotite containing HIMU-type eclogitic domains (recycled from bulk samples of Millbillillie, a brecciated eucrite. Ultra- oceanic crust); and (b) a subduction metasomatised high resolution (sub-µm) ion microprobe depth profiles reveal lithosphere1. However the contribution of lithospheric (mantle different age domains correlative to mineral chemistry in cores and crust) contamination has not been assessed in detail. We and mantles within individual zircons. These compositional

present Re-Os isotope systematics of basalts representative of differences (e.g. [Th/U]zrc and Pb* isotope discordance) can be the range in the AVF geochemistry and use the differences of related to ancient thermal events to the crust of the parent Os isotope systematics between crust and mantle derived body asteroid. Our results confirm that the crust of 4 Vesta lithologies to assess the extent of lithospheric contamination in solidified within a few million years after the formation of these data. CAIs (4561±13 Ma), in good agreement with previous work. Our results show there is a large range in Os Subsequent zircon age re-setting occurred less than 40 Myr concentrations (6-579ppt) and 187Os/188Os isotope ratios later (ca. 4530 Ma), which has also been seen in some 40-39Ar (0.123-0.547). 187Os/188Os vs. 1/188Os diagram shows a broad age plateaux [1]. Analytical modeling shows that for a single positive trend (decreasing Os concentration and increasing Os impactor to be responsible for this effect, it had to have been isotope ratio). Samples showing only little contamination also /10 km in diameter and at high enough velocity (>5 km s-1) to display 187Os/188Os values (0.128-0.138) similar to or slightly account for the thermal field required to re-crystallize zircon. higher than average mantle values (0.121-0.128), consistent Model output also shows that the thermal regime from impact with their derivation from partial melting of a peridotitic could have penetrated at least 10 km into Vesta’s crust. Later source containing HIMU-type eclogitic/pyroxenitic domains. events at ca. 4200 Ma have been recorded in an HED apatite The more radiogenic Os isotopic compositions (>0.15) and 235,238U-207,206Pb age [2] and 40-39Ar age spectra [3]. These low Os content, entirely decoupled from tracers of the mantle younger ages, as well as those coinciding with the Late Heavy sources under the AVF are suggestive of contamination of Bombardment (LHB; ca. 3900 Ma) are not present in asthenospheric mantle-derived magmas by assimilation of Millbillillie zircon. This is attributable to differences in

continental crust during ascent. mineral closure temperatures (Tc zircon >> apatite) and changes to the velocity distributions of impactors in the [1] McGee, L.E., (2012) Melting processes in small basaltic asteroid belt during and after the LHB. systems: the Auckland Volcanic field, New Zealand. PhD Thesis, University of Auckland. [1] Bogard & Garrison (2003) Meteor Planet Sci, 38, 669-710. [2] Zhou et al (2011) 42ndLPSC, Abs. #2575. [3] Bogard (2011) Chemie der Erde, 71, 207-226.

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Early diagenetic alteration of zeolites A comparison of geothermometers in subseafloor sediment of the South for shallow silicic magmas Pacific Gyre J.M. HORA1*, G. WÖRNER1, A. KRONZ1, AND A. K. SCHMITT2 BRYCE HOPPIE* AND ALYSSA WITT 1GZG-Abt. Geochemie, Georg-August Universität, 37077 Department of Chemistry and Geology, Minnesota State Göttingen, Germany (* correspondence: [email protected]) University, Mankato, Minnesota 56001 USA 2Department of Earth and Space Sciences, University of (*correspondence: [email protected]) California, Los Angeles, CA 90095, USA

Zeolite minerals are distributed throughout much of the Several geothermometers can be applied to silicic systems. subseafloor sediment of the South Pacific Gyre (SPG). Aside from ‘traditional’ two phase thermometers, recent Previous studies of deep-sea zeolites suggest that they form calibrations involving partitioning of Si, Ti, and Zr among through the early diagenetic alteration of volcanic debris quartz, titanite, and zircon offer the promise of being able to within the first meter of the subseafloor and subsequently extract T-t paths from zoned crystals. Recognition of P, a undergo dissolution at burial depths exceeding 50 m. In SPG TiO2 a dependence have resulted in some controversy and subseafloor sediment, porosities frequently exceed 80% and SiO2 revisions to these thermometers over the past few years. pore water residence times are greater than 105 years. Difficulty in testing calibrations of these thermometers lies in Consequently, substantial opportunities exist for zeolites having to assume values of input variables such as P and beneath the SPG to undergo post-depositional mineral-to-pore activities of components when comparing to only one or two water interactions. other thermometers. Another complication is that the chemical For this study, over 1,200 randomly selected zeolite species involved in various thermometers diffuse at different crystals were isolated from clay-rich samples of SPG rates, and may result in comparing temperatures locked in at subseafloor sediment obtained during IODP Expedition 329. different times during a cooling history. Crystals were analyzed using optical microscopy, SEM-EDS, By choosing a natural system where there are more and X-ray diffraction techniques. Strata were found to include applicable thermometry equations than free variables (e.g. P, the zeolite minerals phillipsite, (Na, K) (Mg, Ca) Al Si O ! 2 6 10 32 component activities), we can evaluate consistency of results 12H 0, and harmotome, (Na, K) (Ba, Mg, Ca) Al Si O ! 12 2 2 5 11 32 among thermometers in the contexts of (a) differing H O. The zeolites generally exhibit up to 100x increases in 2 diffusivities, (b) testing various calibrations of the same prismatic length within the first 4 to 15 m below the seafloor. thermometer, and (c) a magmatic thermal history. We Larger mean diameters of the phillipsite crystals correspond to + 4+ 2+ compared Fe-Ti oxide, amhibole, amphibole-plagioclase, two- elevated [K ] and [Si ] whereas increased [Ba ] corresponds feldspar, Zr-in-titanite, Ti-in-zircon, and Ti-in-quartz to smaller harmotome crystals. Individual crystal volumes thermometers in rhyodacite dome lavas at Parinacota volcano, exhibit no consistent trend versus burial depth and do not Chile. This also includes thermometry of U-Th-dated zircon correlate to euhedralism, a proxy for crystal dissolution; sub- with crystallization ages ranging from >350 ka to near- and anhehdral crystals are found at all depths and are eruption (~47 ka), and oxide inclusions in titanite. This particularly prevalent in the upper 10 to 25 m of the western comparison indicates: (a) good agreement (T = 740-760°C) study sites. All crystals maintain overall charge balance; among phases where diffusion is slow when P = 3.5kbar, a however, none of the alkali or alkaline earth elements within TiO2 = 0.85, a = 1, interpreted as conditions of crystallization, the zeolites vary consistently with the other cations of similar SiO2 4+ 4+ (b) progressively lower temperatures with increase in electron valence or with [Al ] or [Si ]. diffusivity (quartz ) 720°C, oxides ) 710°C), likely reflecting These results show that SPG subseafloor zeolite minerals latest storage and syn-eruption temperatures, respectively; and are not uniform or predictably variable with respect to their (c) both the pressure-dependences of the Ti-in-zircon textural attributes or composition. Furthermore, they do not thermometer suggested by [1] and [2] agree with other readily corroborate previous explanations of deep-sea zeolite thermometers, whereas the calibration of Ti-in-quartz by [3] diagenesis. Although the observed mineral characteristics produces the most consistent results at the low pressures and could derive from local, shallow subsurface environmental temperatures experienced by these magmas. disparities, they are also suggestive of cation-change and non-

uniform interactions among zeolites and pore water within the [1] Huang & Audetat (2012) GCA 84, 75-89. [2] Ferry & SPG subseafloor environment. Watson (2007) CMP 154, 429-437. [3] Ferriss et al (2008)

Eur. J. Mineral. 20, 745-755.

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Improved Pd-Ag isotopic systematics Reduction process of Cr(VI) by Fe(II) by MC-ICP-MS and humic acid using high-time M.F. HORAN*1, R.W. CARLSON1 AND resolution XAFS analysis M.SCHÖNBÄCHLER1,2 MAYUMI HORI*, KATSUMI SHOZUGAWA, AND 1 Carnegie Institution of Washington, Washington DC 20015 MOTOYUKI MATSUO (*correspondence: [email protected]) Graduate School of Arts and Sciences, The University of 2ETH Zürich, 8092 Zürich, Switzerland Tokyo, Tokyo 153-8902, Japan

(*correspondence: [email protected]) The short-lived 107Pd-107Ag radiogenic decay system has

been used to date volatile depletion, crystallization and shock The reduction of Cr(VI) to Cr(III) starts immediately when in meteorites. Palladium is siderophile with a condensation Cr(VI) is released in the soil. However, Cr(VI) species have temperature (T ) similar to Fe-metal alloy, while Ag is c high mobility in subsurface soil, so the behavior of Cr (VI) chalcophile with T several hundred degrees lower. The c released in the soil is not well understood. In this study, we contrasting characteristics allow Pd-Ag data to provide clarified the detailed initial reduction process at high time chronologic information on early solar system processes resolution. complementary to that provided by other long- and short-lived Three kinds of samples were prepared, 1) Fe(II) pellet, 2) systems. humic acid (HA) pellet, 3) Fe(II)-HA pellet which contributed Early Pd-Ag measurements by thermal ionization mass to Cr(VI) reduction in soil, and then they were spiked with spectrometry (TIMS) yielded the first internal isochron for Cr(VI) solution. In order to estimate the initial reduction high Pd/Ag Group IVA iron meteorites [1]. Because Ag has process of Cr(VI) in samples, we continuously observed the only two isotopes, however, the inability to correct for valence of Cr and the concentration of Cr(VI) in samples after instrumental mass bias limited precisions in 107Ag/109Ag by spiking Cr(VI) solution by measuring consecutively by Quick TIMS to 10-20 " units (parts in 10,000). Over the past decade, X-ray absorption fine structure (QXAFS) for several hours. our group refined a technique for MC-ICP-MS measurements The decrease of concentration of Cr(VI) was observed for of Ag isotopic composition by Faraday cup using added Pd to all samples just after Cr(VI) was spiked to samples. However, correct for mass bias [2,3]. External precision for tens of ng of the reduction of Cr(VI) with Fe(II)-HA experiment showed Ag initially was ±1.3 ", which allowed resolution of the 107Pd reduction process unlike both Fe(II) and HA experiment, decay contribution to the Ag isotopic compositions in low because of HA could also reduce Fe(III) to Fe(II). 97 % of Pd/Ag iron meteorites and . Subsequent use of wet total Cr(VI) was reduced to Cr(III) in 140 min. There were plasma, instead of desolvation, produced more constant mass three phases of reduction processes. Firstly, there was an bias of Ag relative to Pd, yielding precisions of ±0.5 ", and immediate sharp decrease of concentrations of Cr(VI), which showed Pd/Ag correlated with Ag isotope compositions in means rapid reduction reaction. And then, the concentration of carbonaceous chondrites, but also many epsilon units of Cr(VI) gradually decreased. Thereafter, the concentration of natural Ag mass fractionation effects in ordinary chondrites. Cr(VI) decreased sharply again, the reduction reaction was [3,4] rapid. In the first phase, Cr(VI) was rapidly reduced by both To measure low Ag abundances (100s of pg) in volatile Fe(II) and HA. In the second phase, Cr(VI) was mainly depleted , we used simultaneous collection of Ag isotopes reduced by Fe(II). In the third phase, Cr(VI) was reduced by by ion multipliers on the Nu Plasma MC-ICPMS. Mass bias Fe(II), which was reduced by HA. The reduction reaction was corrected by comparison with Ag standards without added became rapid again due to increase of Fe(II). We clarified that Pd. Although precision was only ±10 ", a precise solar system the initial reduction process consisted of three phases, and initial 107Pd/108Pd of 2.8(±0.3) x 10-5 was obtained from the Fe(II) and HA do different contribution to reduction of Cr(VI) Group IVA iron by assuming that the Pd-Ag in each phase. system closed at its 207Pb-206Pb date (4565.3±0.1Ma). Pd-Ag

systematics indicated the interval between volatile depletion and crystallization in the IVA parent body was short, <0.5Ma, suggesting that volatile depletion occurred during planetesimal breakup[5].

[1] Chen et al, GCA, 1990. [2] Carlson et al, 2001 GCA. [3] Schönbächler et al, Mass Spec Ion Proc., 2007 [4] Schönbächler et al GCA 2008. [5] Horan et al, EPSL 2012.

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Geochronological evidence of rapid Helium isotope map of Japan progression of regional KEIKA HORIGUCHI1 , NORITOSHI MORIKAWA1 , metamorphism in Hida Metamorphic MICHIKO OHWADA1, ATSUKO NAKAMA1 AND KOHEI KAZAHAYA1 Complex, southwest Japan 1Crustal fluid Research Group, The Institute of Geology and 1 2 3 K. HORIE *, M. TAKEHARA , Y. TSUTSUMI Geoinformation, Geological Survey of Japan, AIST, 4 AND M. CHO Tsukuba, Ibaraki 305-8567, Japan. 1National Institute of Polar Research, Japan (*correspondence: (keika-horiguchi @ aist.go.jp)

[email protected]) 3 4 2Department of Earth and Planetary Sciences, Kyushu A helium isotope ratio( He/ He ratio) could be a good tracer for estimating the extent of upwelling deep fluids. This University, Japan ([email protected]) 3 3National Museum of Nature and Science, Tokyo, Japan is because the helium has two origins, He in terresial sample is considered to be a primordial isotope derived from the ([email protected]) 4 4Seoul National University, Seoul, Korea mantle, while He is mainly from the crust. The spatial distribution of helium isotope ratios is characterized by high ([email protected]) 3 4 values of 4 to 8Ra (where Ra is the atmospheric He/ He ratio -6 Geochronological constraints from metamorphic rocks of 1.40!10 ) along the volcanic front and in the back-arc provide important information for understanding crustal region at northeastern Japan. In contrast forearc region shows evolution as well as metamorphic processes. The Hida Belt, low values less than 1Ra. This trend has simply been situated at the northern part of southwestern Japan, consists of interpreted that helium in the back-arc region originates from the mantle and that in the fore-arc region is from the crust [e.g. low P/T metamorphic rocks (Hida Metamorphic Complex) 3 4 and Permo-Triassic granitoids, and is an important geological 1, 2]. On the other hand, He/ He ratio of the southwestern unit for discussion about crustal evolution at continental Japan shows no clear and complex distribution. The margin. In this study, zircon U–Pb geochronology was applied complexity cause a lot of discussion for many years [e.g. 1, 3, to the Hida gneisses and the Unazuki metamorphic rocks 4, 5, 6]. However, no end to this discussion is currently in situated at the northeastern part of the Hida Belt to discuss the sight. In recent 20 years, an increasing number of hot spring timing and the duration of regional metamorphism. wells have been constructed in Japan. We collected gas and Zircon grains collected from the Hida gneisses have a dark water samples from hot springs, deep wells, and mineral CL response mantle and a bright CL response rim around springs igneous zoning core. The youngest age population of the whole of Japan, and carried out the analysis of helium igneous zoning core is 253 ± 5 Ma. The mantle and the rim isotope ratio. At the same time, the helium data of previous yielded same age of 247 ± 4 Ma, suggesting a rapid studies are compiled. progression from igneous activity to regional metamorphism. The total number of data points is over 2000 including REE patterns of the rim suggest overgrowth of zircon under 1091samples obtained in our study and 1121 samples from hydrothermal fluids. previous studies. We show helium isotope map of Japan. Protoliths of the Unazuki metamorphic rocks are sedimentary and felsic volcanic rocks of late Carboniferous to [1] Sano and Wakita (1985) J. Geophys. Res., 90, 8729-8741., early Permian age, based on the fossil evidence. U–Pb data of [2] Horiguchi et al (2010) Isl. Arc, 19, 60-70., [3] Matsumoto quartzo-feldspathic schist derived from felsic volcanics yield et al (2003) Earth Planet Sc. Lett., 216, 221-230., [4] Umeda an eruption age of 258 ± 2 Ma, indicating that regional et al (2006) Volcanol. Geoth. Res., 149, 47-61., [5] Morikawa Geochem. J., 42, 42-74. metamorphism occurred after 258 Ma. On the other hand, U– et al (2008) , [6] Sano et al (2009) Pb age of a granite intruding the schist is 253 ± 1 Ma. The Chem. Geol., 266, 50-56. granite contains some xenoliths of the Unazuki schist, in which staurolite is replaced by andalusite and cordierite due to thermal flux from granitic magma. Therefore, the regional kyanite-sillimanite type metamorphism occurred between 258 and 253 Ma, suggesting a rapid metamorphic progression. Further work is needed to confirm this rapidity of crustal- thickening process.

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Carbon isotope biosignatures: Suboxic sediments as an oceanic sink A surface-deep Earth abiotic of isotopically-light cadmium connection T.J. HORNER1,2,*, W.B. HOMOKY3, S.V. GEORGIEV4, H.J. STEIN4,5, J.L. HANNAH4,5, R.A. MILLS3, JUSKE HORITA M. REHKÄMPER6 AND G.M. HENDERSON2 Department of Geosciences, Texas Tech University, Texas 1Dept. Marine Chem. Geochem., Woods Hole Oceanographic 79409-1053 ([email protected]) Institution, USA; *[email protected] 2Dept. Earth Sci., University of Oxford, UK Our quest for identifying the beginning of life in terrestrial 3Ocean and Earth Sci., National Oceanography Centre (and possibly extraterrestrial) environments has been Southampton, University of Southampton, UK hampered by the lack of unequivocal biosignatures in the 4AIRIE Program, Colorado State University, USA absence of many other lines of evidence. The claim for finding 5CEED Centre of Excellence, University of Oslo, NO early life in the /3.85 Ga Istaq Gneiss Complex at Akilia 6Dept. Earth Sci. Eng., Imperial College London, UK Island [1] reignited the half-century old debate on the use of 13 low ' C values (<-20‰) of ancient carbonaceous materials as Riverine and dust fluxes are thought to be the only two an isotope biosignature. It is now well demonstrated that a quantitatively significant sources of dissolved cadmium to the number of possible abiotic pathways exist near Earth-surface ocean. These inputs are balanced, within uncertainty, by burial that lead to the synthesis of various organic and reduced 13 of Cd into suboxic continental margin sediments [1]. Recent carbon compounds depleted in C due to large kinetic isotope studies have characterized the Cd isotopic composition of the effects [2]. Mantle (graphite, diamond, dissolved 13 source terms [2, 3], indicating that the overall Cd isotopic carbons, carbide) with low ' C values (<-20‰) have composition of the inputs is isotopically lighter than average previously been considered recycled sedimentary organic deep-ocean seawater by '114/110Cd ) -0.2 ‰ [4]. The offset carbons or surface contamination. Other possible origins of 13 between seawater and the inputs implies that either the system these low ' C values have been suggested, including (a) is not in steady state, or that suboxic sediments should also be possible mantle heterogeneity since the accretion from the characterized by a Cd isotopic composition that is close to the solar nebula and the core–mantle segregation and (b) input value, and therefore also fractionated toward a lighter unidentified mechanisms and processes for large carbon composition than seawater. isotopic fractionation at high temperatures and pressures. Here, we present Cd isotopic and multi-element Our recent theoretical calculations, along with some geochemical data for suboxic sediments that were sampled experimental studies [3], show that Si/Fe-carbide is very 13 from the Cape Margin, South Africa, during the UK depleted in C relative to other mantle compounds (diamond GEOTRACES 40 °S cruise in 2011 (D357; GA10E). Our Cd and calcite) even under deep-Earth conditions (>1000°C). Our isotopic data suggest that suboxic sediments are indeed modelling shows that redox-controlled C-cycle in the mantle 114/110 13 fractionated from seawater by ' Cd ) -0.2 ‰, and between diamond and Fe-carbide can produce low ' C values represent a significant sink of isotopically light Cd in the (<-20‰) in addition to a primary mantle value (-5±2‰), a 13 modern oceans. Our isotopic mass balance – the first of its pattern similar to that observed from a global ' C distribution kind for Cd – demonstrates that the isotopic composition of of diamond. These mantle-derived diamond and carbide with suboxic sediments balances the inputs, and therefore the low '13C values can be brought up to near surface by mantle isotopic budget of Cd in the oceans. upwelling over geologic time. Thus, now a viable mechanism 13 We explore possible mechanisms for the immobilization exists that can produce low ' C values of diamond and other of isotopically light Cd in suboxic sediments using multi- carbonaceous materials that could have originated from the element geochemical data from both the solid phase and deep-Earth. Abiogenic processes that can produce 13 sediment porewaters. The temporal sensitivity of the Cd carbonaceous materials with low ' C values, both near- isotopic composition of deep-ocean seawater is also surface and in deep-Earth, further challenge our notion of investigated using a simple numerical model, as well as carbon isotope biosignatures for early life. implications for the use of Cd isotopes in paleoceanography. [1] Mojzsis et al (1996) Nature 384 55-59. [2] Horita (2005) Chemical Geology 218, 171-186. [3] Satish-Kumar et al [1] Morford & Emerson (1999) GCA, 63(11), 1735-1750. [2] (2011) EPSL 310 340-348 Schmitt et al (2009) EPSL, 277(1), 262-272. [3] Lambelet et al (2013) EPSL, 361, 64-73. [4] Ripperger et al (2007) EPSL, 261(3), 670-684.

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The LA-ICP-MS U-Th-Pb Network: A global molecular ecological survey Improving data standards in laser of subseafloor microbial communities ablation geochronology TATSUHIKO HOSHINO1, MASAZUMI TSUTSUMI1, 1 1 1 2 3 YUKI MORONO AND FUMIO INAGAKI M.S.A. HORSTWOOD *, J. KOSLER , G. GEHRELS , S.E. JACKSON4, N.J. PEARSON5 AND P.J. SYLVESTER6 1Geomicrobiology Group, Kochi institute for Core Sample 1 Research, Japan Agency for Marine-Earth Science and NERC Isotope Geosciences Laboratory, British Geological Technology (JAMSTEC), Monobe B200, Nankoku, Kochi Survey, Nottingham NG12 5GG, UK. 783-8502, Japan (*correspondence: [email protected]) 2 Dept. of Earth Science & Centre for Geobiology, University Recent advances of the culture-independent molecular of Bergen, Allegaten 41, N-5007 Bergen, Norway. ecological survey such as deep sequencing enable us to ([email protected]) 3 provide precise and detailed views of naturally occuring Dept. of Geosciences, University of Arizona, Tucson AZ microbial communties [1]. For the deep subseafloor microbial 85721, USA. ([email protected]) 4 communities, an improved hot-alkaline DNA extraction Natural Resources Canada, Ottawa, ON K1A 0E8,Canada method have singificantly improved the cell-lysis efficiency, ([email protected]) 5Dept. of Earth and Planetary Sciences, Macquarie University providing less-biased DNA pools for the subsequent moleculer NSW 2109, Australia ([email protected]) ecological analyses [2]. Regarding the molecular 6 quantification, the conventionary used real-time PCR assay is Dept. of Earth Sciences, Memorial University, St. John's NL highly sensitive to the PCR inhibitors such as humic acids and A1B 3X5 Canada ([email protected]) polysaccharides in organic-rich ocean margin sediments. However, a new technique using digital PCR and microfluidic The inter-laboratory comparison (ILC) of laser ablation devices is free of such an inhibitory effect, providing absolute (LA-)ICP-MS U-Th-Pb data is currently compromised by the quantification of the target genes [3]. Using these newly use of multiple and disparate 1) mass spectrometer and laser standardized molecular ecological techniques, a new global- ablation platforms, 2) data processing packages and scale molecular survery of subseafloor microbial communities independent spreadsheets, and 3) geological factors, which in has been planed. combination, result in differing results for the same materials In this project, we have currently extracted DNA from and potentially misleading and inaccurate interpretations. over 200 deep-frozen samples from 15 drilling sites using a Since 2006, an international network of LA-ICP-MS U-Th-Pb new hot-alkaline method: e.g., off Peru and eastern equatorial specialists has been addressing these issues, and measures and Pacific (ODP Leg 201), Juan de Fuca ridge flank (IODP Exp. documentation are now in place to inform new and existing practitioners of better practice in acquiring, handling, reducing 301), South Pacific Gyre (IODP Exp. 329), Nankai Trough (IODP Exp. 315 and 316), off Shimokita of Japan (CK0606, and interpreting LA-ICP-MS U-Th-Pb data. These measures IODP Exp. 337), Gulf of Mexico (IODP 308), Porcupine include: completion and documentation of a detrital zircon- carbonate mound (IODP Exp. 307). These envionmental DNA focussed ILC, a defined uncertainty propagation protocol, pools provide an unprecedented opportunity to study defined tables for publishing data and acquisition information, biogeographical distribution and diversity of bacterial and peer-reviewed publications [1], provision of reference material archaeal 16S rRNA and some other ecologically significant sets for long-term validation of lab performance, the running functional genes with a systematic analytical scheme. of workshops and shortcourses, recommendations with respect

to the interpretation of detrital zircon data and a maintained [1] Hoshino, et al, Front. Microbio., 2, no. 231 (2011). [2] website with resources and information (www.plasmage.org). Morono, et al, submitted. [3] Hoshino & Inagaki, Syst. Appl. These measures will: a) improve the standard and accuracy of Microbiol., 35, 390-395 (2012). published LA-ICP-MS U-Th-Pb data, b) allow better

comparability of published data, c) ensure appropriate age uncertainty quantification and, ultimately, d) improve the rigour of geological interpretation. New insights into achievable ILC performance and future Network activities will be highlighted.

[1] Kosler et al (in review)

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In situ lithium isotope measurements Stable isotopic record of a Himalayan for spodumene using ice core during the last millennium

LA-MC-ICP-MS S. HOU* KEJUN HOU School of Geographic and Oceanographic Sciences, Nanjing Key laboratory of Metallogeny and Mineral Assessment, University, Nanjing 210093, China. (*correspondence: Ministry of Land and Resources, Institute of Mineral [email protected])

Resources([email protected]) A 108.8 m ice core to bedrock recovered from the East As a useful geochemical tracer, the lithium isotope system Rongbuk (ER) Glacier (28.03 N, 86.96 E, 6518 m a.s.l.) on the northeast ridge of Mt. Qomolangma (Everest) provides a high- has been used to study some important geological or resolution stable isotopic record of the last millennium (3044 geochemical problems. Lithium isotope can be readily ! fractionated during geological processes in nature because of samples). Interpretation of the Himalayan ice core D and !18O records is multivocal. For instance, Thompson et al [1] the large mass difference (16.7%) between its stable isotopes, suggested that the long-term !18O variability recorded in the 6Li and 7Li, whose abundances are 7.52% and 92.48%, Himalayan Dasuopu ice core was attributed to changes in local respectively. Therefore, the application of the lithium isotopic temperature, while Cai et al [2] suggested that precipitation, system has important significance in the fields of rather than temperature, was a major factor controlling !18O in cosmochemistry, continental crust weathering processes, precipitation on orbital time scales in the south-central Tibetan oceanic crust thermal activity and alteration, continental plate Plateau. However, the linear combination of !D and !18O (i.e., subduction and crust-mantle material recycling, surface water deuterium excess or d=!D–8!18O) is a good proxy for changes geochemistry, halogenic water origin and evolution, and so on. in atmospheric circulation in the Himalayas [3]. A feature for Therefore, this technique will surely become a useful the d time series of the ER ice core is the significantly positive geochemical tool in the Earth sciences.(Tian et al, 2012) phase during the period of middle 15th century and the In this study, we have developed a direct in situ lithium significantly negative phase during the period of middle1] isotope analytical method for spodumene using LA-MC-ICP- Thompson et al (2010). Science 289, 1916-1919. [2] Cai et al MS. Our LA-MC-ICP-MS homogeneity testing results show (2010). Geology, 38(3), 243–246. [3] Pang et al (2012). that the four in-house spodumene standards have constant th 7Li/6Li compositons. The precision of measured '7Li in these Climatic Research, 53(1), 1–12. 18 century, with a reversal around middle 17th century (Figure 1). This might indicate a homogeneous spodumene is better than 1.5‰. And all of these changeover of the atmospheric circulation regime during the in situ analytical results are in good agreement with those th century. We suggest that, on the centennial time scale, the results measured by solution MC-ICP-MS method within 17 Indian Summer Monsoon weakened since the early 15th error. century, reaching its minimum around the middle 17th century.

The time interval of the 15-17th centuries is the transition from

the Medieval Climatic Optimum to the Little Ice Age, and the modification of the atmospheric processes in the Asian monsoon regime may be the reflection of global change in the climatic processes during this time interval.

Figure 1. Result of wavelet analysis of d (solid lines stand for positive values, dotted lines for negative values, and dashed lines for the boundary effect. The shadow denotes the area passing the significant test with confidence of 95.

[1] Thompson et al (2010). Science 289, 1916-1919. [2] Cai et al (2010). Geology, 38(3), 243–246. [3] Pang et al (2012). Climatic Research, 53(1), 1–12.

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The Cihai diabase in the Beishan Challenges in constraining and region, NW China: Isotope understanding Strombolian geochronology, geochemistry and volcanism implications for Cornwall-style iron BF HOUGHTON1, J TADDEUCCI2 AND M EDMONDS3, mineralization 1School of Ocean and Earth Science and Technology, 1 1 University of Hawaii at Manoa, Hawaii, USA. TONG HOU AND ZHAO-CHONG ZHANG 2Dept. of Seismology and Tectonophysics, Istituto Nazionale 1State Key Laboratory of Geological Processes and Mineral di Geofisica e Vulcanologia, Roma, Italy Resources, China University of Geosciences, Beijing, 3Earth Sciences Department, University of Cambridge, 100083, China ([email protected]) Downing Street, Cambridge CB2 3EQ, UK

Diabase dykes in Cihai, Beishan region, NW China are Activity at Stromboli is exceptionally well characterised spatially and temporally associated with 'Cornwall-type' iron on most time scales but it remains a challenge to identify what deposits. U-Pb dating of zircons from a diabase dyke using portion of that activity should be defined as “Strombolian’ in laser ablation inductively coupled plasma mass spectrometry the strict sense of naming the eruption style, in a fashion that (LA-ICP-MS) yields an age of 128.5±0.3 Ma. Most of the is useful elsewhere. Here we look at delineating the limits of diabases show low Mg-numbers, suggesting evolved magmas. ‘Strombolian style’, particularly in the context of demarcation The diabase dykes show typical ophitic or sub-ophitic from Hawaiian fountaining eruptions. textures, and are dominantly composed of phenocrysts of That demarcation has generally been articulated in terms plagioclase and clinopyroxene, with minor and varying of transient versus sustained activity linked to mechanical amounts of biotite and hornblende, and minor disseminated decoupling versus partial coupling of exsolved volatiles. magnetite. The diabase dykes are characterized by minor However, while sustained fountains are steady, they are variation in SiO2 (44.67-49.76 wt.%) and MnO (0.14-0.26 seldom steady, and violent Strombolian events can last for wt.%), but show a marked range of Al2O3 (10.66-14.21 wt.%), minutes. total Fe2O3 (9.52-13.88 wt.%), TiO2 (0.66-2.82 wt.%) and Plotting basaltic activity in viscosity-mass eruption rate relatively high MgO (4.87-9.29 wt.%) with an Mg# value space reveals some of the issues. Individual Strombolian [atomic Mg/(Mg+Fe2+)] of up to 66. The Cihai diabases explosions occupy the short duration, low eruption rate corner possibly experienced fractional crystallization of olivine + of such a plot, very clearly distinguished from high Hawaiian clinopyroxene and minor crustal contamination during the fountains that have durations that are 3 to 5 orders of differentiation process. Prominent negative Nb, Ta and Ti magnitude longer and mass discharge rates that are 10 to 100 anomalies suggest derivation from subduction-modified times larger. However the spectrum of activity called names mantle. Furthermore, the rocks have relatively unradiogenic such as ‘low fountains’, ‘gas pistoning’ and ‘violent Sr- and Nd-isotopic ratios. These characteristics probably Strombolian’ defines a grey scale between these extremes. reflect partial melting of a subduction component in the source Finally on what time scale can we define a Strombolian (or mantle lithosphere through heat input from an upwelling Hawaiian) ‘eruption”, i.e., what is the most characteristic time asthenospheric mantle. Such processes probably occurred scale - a transient explosion of seconds duration or centuries within an extensional setting during the Early Cretaceous in of continual but varied activity? the Beishan area. The iron-rich fluids were derived from deep sources, and the iron ores were concentrated through a convection cell driven by temperature gradients established by the intrusion of the diabase sills. The combined processes of subduction-related enrichment in the source, shallow depth of emplacement, and the involvement of large-scale circulation of basinal brines from an evaporitic source are inferred to have contributed to the formation of the 'Cornwall-type' mineralization in Cihai.

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Lithospheric mantle downwelling Newly measured enthalpies of K-Na beneath the Southeast Carpathians mixing for low albite - microcline GREGORY A. HOUSEMAN, PIROSKA LORINCZI, YONG crystalline solutions REN AND GRAHAM W. STUART 1 GUY L. HOVIS School of Earth and Environment, University of Leeds, Leeds, 1 Department of Geology & Environmental Geosciences, LS2 9JT (correspondance to: [email protected]) Lafayette College, Easton, PA 18042 USA

The South Carpathian Project, a major seismological Earlier studies [1,2] on the thermodynamic mixing experiment carried out during 2009-2011 by the University of properties of the low albite - microcline system reported Leeds, the National Institute of Earth Physics in Bucharest, the enthalpies of K-Na mixing that were nearly symmetric with Eötvös Loránd Geophysical Institute in Budapest, and the regard to composition, despite a solvus [3] and Gibbs free Seismological Survey of Serbia in Belgrade, has resulted in energies of mixing [4,5] that require compositionally the most detailed tomographic images yet obtained of the asymmetric relationships. To refine earlier results, new data upper mantle structure beneath the Pannonian – Carpathian have been collected at a particularly large number (21) of region [1]. These images shed new light on the unique compositions across this series. Duplicate solution geological structure which is responsible for the damaging calorimetric experiments on each of these samples at 50 °C in earthquakes that occur in the upper mantle beneath the 20.1 wt% HF have produced highly precise calorimetric data Vrancea Zone of the South-east Carpathians. A sub-vertical having an average standard deviation per sample of just 0.06% high-velocity body extending down to the top of the Mantle of the heats of solution. The new study, which reveals a Transition Zone is interpreted as downwelling mantle maximum 8.7 kJ/mol enthalpy of mixing (H ) at N = 0.39, lithosphere. The main mass of fast (presumably dense) ex Or demonstrates that detail in data at the sodic end of the series is material is located directly beneath the seismic activity. The crucial to definition of asymmetry in H . The greater mixing earthquakes are caused by vertical stretching at strain-rates ex magnitudes for this series relative to those for analbite - which imply that the mantle at 200 km is moving downward at sanidine solutions (newly investigated via a 20-sample series) about 20 mm/yr relative to the surface. correlate well with the comparatively higher critical Three-dimensional numerical experiments assuming temperature of the low albite - microcline solvus [3] relative to viscous flow support the interpretation that the drip-like that for analbite - sanidine [e.g., 6]. Entropies of K-Na mixing structure that we image may be a natural consequence of a have been calculated by combining the new enthalpy data with Rayleigh-Taylor instability developing from an unstable Gibbs free energies of mixing derived from phase equilibrium stratification of mantle lithosphere above asthenosphere, and studies [4,5]; these may be compared with entropy data based triggered by recent convergence of Adria and Europe. The on the recent heat capacity measurements of Benisek and depth distribution of seismic-moment release rate is most others [7]. easily explained if this high velocity structure is produced by a

Rayleigh-Taylor instability. The present high rate of tectonic [1] Waldbaum & Robie, 1971, Z. Krist. [2] Hovis, 1988, J. activity in this region is probably short-lived on a geological Petrol. [3] Bachinski & Müller, 1971, J. Petrol. [4] Delbove, scale (< 1 Myr) but is likely to increase in energy before it is 1975, Amer. Mineral. [5] Hovis, Delbove, & Roll, 1991, abates. The circumstances of this tectonic activity support the Amer. Mineral. [6] Smith & Parsons, 1974, Mineral. Mag. [7] idea that Rayleigh-Taylor instability of the mantle lithosphere personal communication. requires relatively dense mantle lithosphere activated by local

plate convergence.

[1] Ren, Y., Stuart, G., Houseman, G., et al (2002), Earth Planet. Sci. Lett., 349-350, 139-152.

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Nitrogen isotope systematics and Sorption behavior of lithium origins of mixed-habit diamonds MANDY HOYER AND NICOLAI ALEXEJI KUMMER *D. HOWELL1, R.A. STERN2, W.L. GRFFIN1, TU Bergakademie Freiberg, Department of Hydrogeology, R. SOUTHWORTH3,4, S. MIKHAIL5, T. STACHEL2, D-09599 Freiberg, [email protected] A.B. VERCHOVSKY4, A.P.JONES3, SUZANNE Y.O’REILLY1 AND N.J. PEARSON1. Salar the Uyuni is one of the greatest sources for Li being 1 presently assessed. It is not yet understood why one observes CCFS ARC Center of Excellence, and GEMOC, Macquarie great Li enrichment in the delta areas of past and presently University, Sydney, NSW 2109, Australia. inflowing rivers. One theory is temporary sorption and (* correspondence: [email protected]). subsequent desorption by clay minerals that are enriched in 2 Canadian Center for Isotopic Microanalysis, University of these inflow areas. Alberta, Edmonton, AB, T6G 2E3, Canada. Li sorption on clay minerals, namely kaolinite and 3Department of Earth Sciences, University College London, bentonite, and on clinoptilolite, a zeolite, was studied in batch Gower Street, London, WC1E 6BT, UK. experiments with subsequent ICP-MS analysis. Solid/solution 4Department of Physical Sciences, The Open University, ratio was 1:4; shaking time was 24 hours; pH was varied Walton Hall, Keynes, MK7 6AA, UK. between 2 and 10, with focus on pH 6 and 8 as pH in the Salar 5Geophysical Laboratory, Carnegie Institute of Washington, is circum-neutral. Li concentration in the solutions was varied 5251 Broad Branch Road NW, Washington DC, 20015, between 1.5 and 750 mM; sodium concentration between 0.01 USA. and 5 M. It was found that Li was sorbed by all minerals; highest Mixed-habit diamonds form when growth occurs by two sorption being achieved at lowest sodium and highest Li different simultaneous growth mechanisms [1, 2]. The two concentration for clinoptilolite (3890 ppm) and bentonite (3820 ppm); at 3 M Na and highest Li concentration for crystal habits are smooth, flat {111} crystal faces (octahedral kaolinite (1250 ppm). Absolute Li sorption at pH 6 and 8 was growth) and curved, hummocky, non-faceted surfaces with a similar and increased with increasing Li concentration in the mean orientation of {100}, but this can be inclined by up to o initial solution at constant Na concentration. Relative Li 30 (cuboid growth). This type of growth can produce a range sorption decreased due to limited exchange sites on the of centre-cross or star-shaped patterns within the diamond [3], mineral’s surface. At constant Li concentration, increasing Na which are the result of light-scattering defects that occur only caused Li sorption decreased by competition. in the cuboid sectors. When these defects are graphitized and pH changes altered minerals’ surface charge by thus opaque, the cuboid growth sectors appear much darker (de)protonation, caused structural changes, or decomposition. than the gem-quality octahedral sectors. For bentonite and clinoptilolite, pH-dependent sorption results Analysis of this type of diamond has shown that carbon scattered. The reason for that is not known. For kaolinite isotopes show no partitioning between growth sectors [4]. sorption was maximal at pH 2-4 which could be explained by However, nitrogen contents are much higher in the octahedral surface complexation or incorporation in the crystal structure. sectors (enriched by up to 160% compared with that of cuboid Above pH 5, kaolinite probably transformed to gibbsite with sectors), while nickel and cobalt are partitioned into the effects on surface charge and on Li sorption. cuboid sectors if available in the diamond-forming fluid [5]. This study showed that clay minerals and zeolites are Few nitrogen isotope data exist for these types of diamonds. effective Li sorbents and may contribute to elevated Li One study showed no N-isotope fractionation between growth concentration at the freshwater inflows of Salar de Uyuni. sectors [6] but the sample used in that study is not thought to be a true mixed-habit diamond. This study compares nitrogen-isotope data obtained via SIMS and by step-wise oxidation mass spectrometry from both octahedral and cuboid growth sectors, with the goal of investigating both isotopic fractionation and the source of nitrogen in these unusually N-rich diamonds.

[1] Frank (1967) Proc. Int. Industrial Diamond Conf., 119- 135. [2] Lang (1974) Proc. R. Soc. Lond., A. 340, 233-248, [3] Welbourn et al (1989) J. Crystal Growth, 94, 229-252, [4] Howell et al (2013) Am. Min., 98, 66-77, [5] Howell et al (in press), Chem. Geol., [6] Cartigny et al (2003), Geochim. Cosmochim. Acta, 67, 1571-1576.

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Thermodynamics of the C-H-O fluids: Comparison of 228Ra and High pressure experiments on microstructure derived ocean mixing dissociation of carbonates and hydrides rates and chemical fluxes in the Cape R. HRUBIAK1*, V. DROZD1 AND S.K. SAXENA1, Basin 1 Department of Mechanical and Materials Engineering, YU-TE HSIEH1,2*, WALTER GEIBERT3,4, Florida International University, Miami, FL 33199, MATTHEW R. PALMER5, E. MALCOLM S. WOODWARD6, USA (*correspondence: [email protected]) AND GIDEON M. HENDERSON1 1 Department of Earth Sciences, University of Oxford, UK Understanding the chemistry of carbon in deep Earth’s (*correspondence: [email protected]; [email protected]) interior requires thermodynamic data on the multicomponent 2 Present address: Department of EAPS, Massachusetts C-H-O fluid. Experimental data on such fluids at high Institute of Technology, Cambridge, MA, USA temperature and high pressure mantle conditions is quite rare. 3Scool of Geosciences, University of Edinburgh, UK In this study we use new experimental methods and 4 Scottish Association for Marine Sciences, UK computations to produce pressure-volume-temperature (P-V- 5 National Oceanography Centre, Liverpool, UK T) equation of state (EoS) data on CO and H fluids to 2 2 6Plymouth Marine Laboratory, UK pressures of 100 GPa and very high temperatures. The thermodynamic properties and P-V-T EoS for CO 2 Diapycnal mixing from below is a critical route by which and H fluids are assessed by combining experimental data on 2 nutrients and other chemical species are introduced to the equillibrium conditions for several carbonate and hydride sunlit surface ocean. Instantaneous mixing rates can be dissociation reactions involving these fluids with P-V-T EoS’ assessed by shipboard measurements of velocity of solid phases involved in the given reactions. Experimental microstructure in the water column. Radium-228, a daughter P-V-T data on several carbonates and hydrides used in this 232 of Th, has a half life of 5.75 years, and is mixed into the study was extensively collected from literature and missing P- ocean interior from ocean shelves and downwards from the V-T data was measured using resistively heated and laser surface by diapycnal mixing. It therefore provides a means to heated diamond anvil cell and in situ x-ray diffraction. The P- assess the long-term average mixing rates in the oceans. In V-T EoS’ for the CO and H are thus self consistent with 2 2 this study, we compare instantaneous mixing rates from experimental phase equilibrium data and standard velocity microstructure with long-term rates from 228Ra for thermochemical data. The EoS’ are also shown to be waters of the Cape Basin. We use these measured mixing rates consistent with results obtained independently using molecular to assess the supply of nutrients to the surface ocean in this dynamics calculations [1]. region, and the temoral variability of this supply. The newly created thermodynamic database was used to Twenty five seawater samples were collected from the calculate high pressure and temperature phase equilibrium in Cape Basin during the 2010 UK GEOTRACES cruise several binary, ternary and multicomponent systems. (GA10E) and analysed for high-precision 228Ra and 226Ra

concentrations by MC-ICP-MS. We estimated vertical and The authors wish to acknowledge the supoort and horizontal ocean mixing rates from this data using 1D mixing collaboration of the Deep Carbon Observatory models to derive rates of 0.9 – 2.1 cm2s-1 and 3.8 ! 107 cm2s-1 respectively. The rates of diapycnal mixing indicate sufficient [1] Belonoshko, A.B, Shi, P., Saxena, S.K. (1992) Computer nutrient supply to drive the productivity in downward organic and Geosciences 18, 1267–1269. carbon fluxes of 3.1 – 3.3 mmol C m-2d-1 in this region – in close agreement with estimates from other proxies. The long- term averages are compared with instantaneous mixing rate and nutrient supply derived from microstructure measurements from the same cruise to assess the merits of the two approaches and variation in the mixing environment.

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DFT+U investigations of spin Meso- to Neo-proterozoic magmatic crossovers in lower-mantle minerals events and their geological HAN HSU significance: evidences from detrital Department of Physics, National Central University, Jhongli zircon U-Pb ages of the Jurassic and City, Taoyuan 32001, Taiwan ([email protected]) Cambrian sedimentary rocks in

The total electron spin of a transition-metal ion in a Xishan area, Beijing city, China crystalline solid can vary with many factors, including BO HU 1, MINGGUO ZHAI2, PENG PENG 2 AND FU LIU 2 temperature, pressure, and strain. This phenomenon, known as 1 spin crossover, is of great technological potential, as it allows Key Laboratory of Western Mineral Resources and artificial control of magnetic properties of materials. Not as Geological Engineering, Ministry of Education, College of widely known, spin crossover may also play a significant role Earth Science and Resources, Chang’an University, Xi’an in geophysics. As pressure and temperature increase with 710054, China ([email protected]) 2 depth in the Earth, iron incorporated in minerals can undergo a Institute of Geology and Geophysics, Chinese Academy of spin crossover. A well studied example is ferropericlase, the Sciences, P. O. Box 9825, Beijing 100029, China second most abundant mineral in the Earth’s lower mantle. In this mineral, a high-spin (HS) to low-spin (LS) crossover Whether any magmatic records corresponding to the occurs in the pressure range of 40-55 GPa, accompanied by assembly and breaking up of the supercontinent Rodinia are elastic, thermodynamic, optical, and conducting anomalies. preserved in the North China Craton (NCC) is a key issue to In contrast to ferropericlase, spin crossovers in magnesium understand the Proterozoic tectonic evolution of the NCC and

silicate (MgSiO3) perovskite and post-perovskite, the major its correlation to the supercontinent Rodinia. LA-ICP-MS U- mineral phases in the lower mantle, have been controversial Pb dating results of detrital zircons from Jurassic and for years, due to the complicated nature of these minerals and Cambrian sedimentary rocks in the Xishan area, Beijing city, the difficulty in probing iron spin state directly. Using density central part of the NCC show that there are not only ~507 Ma functional theory + Hubbard U (DFT+U) calculations, we cambrian age peaks, but also ~2.5 Ga, ~2.1 Ga, 1.8-1.66 Ga,

investigated spin crossovers in MgSiO3 perovskite and post- ~1.56 Ga, ~1.38 Ga, ~1.14 Ga, ~912 Ma, ~814 Ma, ~740 Ma perovskite, and our results clarify the iron spin controversy in and ~630 Ma precambrian age records in Cambrian fine both mineral phases. We also show that Mössbauer sandstone. Also, there are not only ~484 Ma, ~267 Ma, ~241 spectroscopy, combined with first-principles calculations, can Ma and ~188 Ma phanerozoic age peaks, but also ~2.77 Ga, be a reliable tool to unambiguously identify iron spin state at ~2.5 Ga, ~2.0 Ga, ~1.78 Ga, ~1.6 Ga, ~1.2 Ga and 848Ma high pressure [1-4]. precambrian age records in Jurassic silty mudstone and fine sandstone. Most of Neoarchean and Paleoproterozoic age [1] Hsu et al (2010) Earth Planet. Sci. Lett. 294, 19-26. [2] peaks correspond to significant tectono-magmatic-thermal Hsu et al (2011) Phys. Rev. Lett. 106, 118501. [3] Yu et al events previously recognized in the NCC. 1.78-1.38 Ga age (2012) Earth Planet. Sci. Lett. 331-332, 1-7. [4] Hsu et al peaks correspond to late Paleoproterozoic to Mesoproterozoic (2012) Earth Planet. Sci. Lett. 359-360, 34-39. multi phase rifting events in the NCC. Zircon ages of 1.3-1.0 Ga and 1.0-0.6 Ga indicate that during the deposition of these sediments there have been significant contributions from 1.3- 1.0 Ga and 1.0-0.6 Ga magmatic rocks in the NCC. The magmatic rocks during these periods, which were common in the South China Craton (SCC) and were explained to relate to the assembly and breaking up of the supercontinent Rodinia, were seldom reported in the NCC so far. The finding of 1.3- 1.0 Ga and 1.0-0.6 Ga detrital zircons in the NCC may provide clues to understand the possible relationship of the NCC, the SCC and the supercontinent Rodinia. This work is supported by National Nature Science Foundation of China (Grant No. 41002064) and Special Fund for Basic Scientific Research of Central Colleges, Chang’an University (Grant No. CHD2011JC163).

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Altitudinal ! 18O gradients from Hydrochemistry and isotope evidence Chinese stalagmites provide records of groundwater evolution of Holocene humidity variation and recharge in CHAOYONG HU1 GIDEON M. HENDERSON2 JIN LIAO1 Poyang Lake, South China 1 1 1 JIAOYANG RUAN CHENGZHAN LI SHUCHENG XIE 1!2 1!2 1!2 3 HU CHUNHUA , ZHOU PENG , HUANG DAN , AND KATHLEEN JOHNSON 1,2 1"2 LI LIYANG AND ZHOU WENBIN * 1 State key laboratory of biology and environmental geology, 1 School of Environmental and Chemical Engineering, China University of Geosciences, Wuhan, 430074 Nanchang University, Nanchang, 330031, China ([email protected]) 2 (*correspondence: [email protected]) Department of Earth Sciences, University of Oxford, South 2 Key Laboratory of Lake Poyang Environment and Resource Parks Road, Oxford OX23AN, UK. Utilization, Ministry of Education, Nanchang University, ([email protected]) Nanchang, 330029, China 3Department of Earth System Science, University of

California, Irvine, CA 92697. In recent decades, a systematic research of groundwater

system is imperative for the increasingly prominent Humidity is one of the fundamental variables controlling contradiction between supply and demand of water. In this the energy balance of the climate, and plays a critical role in work, environmental factors, main zwitterions, hydrogen and Earth’s ecosystems. Its reconstruction would aid considerably oxygen isotopes composition in groundwater were researched in assessing the mechanisms driving past changes observed in in dry season and wet season. Groundwater evolution and paleoclimate records. Paleohumidity has been reconstructed recharge were studied with the purposes of anzlyzing qualitatively from the pollen and tree ring data, but not yet hydrochemical characteristics and evolution laws [1], as well from speleothem records, due to the uncertain interpretation of as helping rebuild the geochemical evolution [2]. In addition, speleothem geochemical proxies. Here we propose a novel the recharge rates of different landscape units were estimated proxy for paleo-humidity based on the altitudinal !18O by hydrogen oxygen isotopes during investigation period. gradient derived from two speleothems with different altitude + 2+ The results show that: Na and Ca are the main cations of of rainfall recharge in closely spaced caves. We then use this - groundwater in research area, and HCO is the main anion, proxy to reconstruct a Holocene humidity record in the middle 3 seasonal change has influence on spatiotemporal variation of reaches of the Yangtze river. Two factors affect the altitudinal - 18 area hydrochemistry, and its type is mainly present in HCO3 ! O gradient of precipitation, the lapse rate of temperature + + 18 —(Na +K ); the composition of 'D and ' O has different and relative humidity. In the case of speleothems, the cave characteristics for seasonal change, it mainly controlled by temperature effect (negative effect) offsets the temperature precipitation. Groundwater anions type transforms from induced isotopic fractionation in precipitation (positive effect), - 2- - - HCO —SO to HCO —Cl when the season changes from and relative humidity is likely to be the major controller of 3 4 3 18 dry season to rainy season, and cation type drifting and ! O gradients between speleothems with recharge from + + 2+ + + evoluting from (Na +K )—Ca to (Na +K ). The results of different heights. !18O in recently formed carbonate from two hydrogen and oxygen isotopic mixing ratios shows that there caves in Qingjiang valley, Hubei, China, supports this is significant difference on water recharging of groundwater interpretation, with larger !18O gradients in periods of lower system in different geomorphic units, and it reflects that the relative humidity. Based on this observation, we reconstruct origin and evolution of groundwater response to Holocene relative humidity from the high resolution geomorphology sensitively. speleothem !18O records from Heshang and Sanbao caves. The reconstructed record indicates a slight increase in RH during [1] Zhao et al (2007) Ecology and Environment 16, 1620- the Holocene, with lowest values at 8.2 kyr BP. Independent 1626. [2] Hackley et al (2010) Geological Soc America122, !13 hydrological records of Mg/Ca and C from the Heshang 1047-1066. !18 speleothem vary in a similar pattern to the altitudinal O gradients, which supports the reconstruction of humidity for the Holocene of this region.

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The characterastics of polycyclic Mineral compositions of Lower aromatic hydrocarbons (PAHs) in the Silurian Longmaxi Formation, drainage basin of the Liao River, Sichuan Basin, China Northeast China PEI-QING HU, JUAN SHEN AND WAN-XIANG RAO 1 1,2 2,3 JIAN HU *, YAN-LIN ZHANG BAO-JIAN LIU , SI- Key Laboratory of Mineral Resources in Western 1 1 LIANG LI AND JIN GUAN 23 China(Gansu Province) &School of Earth Sciences, 1 Lanzhou University, Lanzhou 730000, China Institute of Geochemistry, Chinese Academy of Sciences, ([email protected]) Guiyang 550002, PR China (*correspondence:

[email protected]) 2Graduate University of Chinese Academy of Sciences, The Sichuan Basin is a prolific hydrocarbon region and is Beijing 100049, China currently China’s largest gas-producing region. In order to 3Guangzhou Institute of Geochemistry, Chinese Academy of study the mineral properties, composition and the relationship with the organic matter characteristics in Lower Silurian Sciences, Guangzhou 510640, China Longmaxi Formation shale, 30 shales from Longmaxi Sixteen polycyclic aromatic hydrocarbons (PAHs) in surface Formation fresh outcrop cross sections located in Changning water and suspended particulate matter (SPM) in the drainage County in Sichuan basin were analyzed. basin of Liao River were determined by GC/MS. The The analysis result shows that mineral compositions are concentration and distribution characteristics, pollution levels, brittle(fragment) minerals: quartz, feldspars, mica, pyrite; and sources of PAHs were discussed. The total PAHs siliciclastic and calcite minerals: Chalcedony, calcite and concentration ranged from 0.41 to 76.45%g·g-1 (dry weight) in dolomite; and clay minerals: Illite, chlorite and SPM, and 32.57 to 108.47ng·L-1 in surface water, respectively. montmorillonite. These samples display significant variations The PAHs concentration in west Liao River is higher than that in the proportions of detritus derived extrabasinal and in east Liao River and Liao River main stream. The intrabasinal sources. Quartz in particular occurs in both clay- compositions of PAHs are predominant by low ring PAHs size and silt-size fractions of both intrabasinal and extrabasinal (two and three-ring PAHs), and the percentage of low ring origin and it is important that lots of dark luminescing PAHs in dissolved phase is higher than that in SPM. The microcrystalline (clay-size) quartz closely intergrown with percentage of two-ring PAHs in dissolved phase is highest clay minerals in the samples. The organic matter occurrence with an average of 68.19%, while the percentage of three-ring modes have important relationship with the mineral character. PAHs in SPM is highest with an average of 66.28%, The finer fracture in the fragment minerals have huge respectively. Compared with other rivers in China and the influence to the produce and travel of the shale gas. world, the PAHs concentrations in Liao River drainage basin

are at a lower level, but some branches are PAHs- contaminated to some extent. This study was supported by The National Basic Research Diagnostic ratios of Ipy/(Ipy+Bpe) and Fla/Fla+Pyr) were Program of China (2012CB214701) and NSF of China used to identify the PAHs sources, and the result suggested the (40873005). main sources of PAHs would be petroleum and fossil fuel combustion-based, which are resulted from complex energy structure of Liaoning province.

This work was supported by Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-EW-102) and National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No. 2012ZX07503-003-001)

www.minersoc.org DOI:10.1180/minmag.2013.077.5.8

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Kinetic experiments of actinolite in Hydrocarbon geology characteristics CaCl2 –HCl-H2O up to 400°C and exploring prospect of ultradeep SHUMIN HU*, RONGHUA ZHANG AND XUETONG ZHANG layers onshore China Laboratory of Geochemical Kinetics, MLR Key Laboratory of HU SUYUN1, ZOU CAINENG2, HOU LIANHUA3 Metallogeny and Mineral Assessment, Institute of Mineral AND ZHU RUKAI 4 Resources, Chinese Academy of Geological Sciences, 1 Research Institute of Petroleum Exploration and Baiwanzhuang Road 26, Beijing 100037, P.R.China Development, PetroChina, Beijing, China, (*correspondence: [email protected]) [email protected] 2 Research Institute of Petroleum Exploration and Actinolite dissolution rates in HCl-H O and CaCl -HCl- 2 2 Development, PetroChina, Beijing, China, H O were measured at temperature ranging from 25 to 400°C 2 [email protected] and at 23 MPa. The dissolution experiments were performed 3 Research Institute of Petroleum Exploration and in a flow-through reactor. The results provide new insight into Development, PetroChina, Beijing, China, the rate limiting reactions governing actinolite dissolution [email protected] behavior at far from equilibrium, particularly at temperatures 4 Research Institute of Petroleum Exploration and above 300°C. As actinolite dissolves in aqueous solutions, the Development, PetroChina, Beijing, China, relative release rates for breaking various metal–oxygen bonds [email protected] in actinolite are different. Results show that Ca, Mg, Fe and Al

dissolve faster than Si at temperatures of 25-300°C, but slower As the geology knowledge becoming deeper and the at 300°C. Ca and Mg release faster than Si at temperatures of exploring technology developing, the hydrocarbon exploring 350°C-374°C. All of release rates vary with temperatures and prospect in deep-ultradeep layers is being recognized by the pH. The release rate of Si increases with temperature from 20 world. Chinese petroliferous basins suffered divergency in to 300°C, and then decreases with continued increasing Eopaleozoic, transition between marine and continent in temperature from 300 to 400°C. The maximum release rate of Neopaleozoic, and strong compression in Meso-cenozoic. The Si is reached at 300°C. Experiments show that dissolution basins are mainly superimposition basins, which have upper stoichiometry of actinolite is affected by temperature and pH. and lower tectonic layers. Previous exploration mainly focus Results of actinolite dissolved in CaCl -HCl-H O indicate that 2 2 on upper layer, in recent years, CNPC has achieved a series of the release ratios of m /m and m /m in the effluent at Ca Si Mg Si discoveries in deep-ultradeep layers of petroliferous basins 200°C are close to stoichiometric number of these element onshore China through strengthening hydrocarbon geology moles in one mole of actinolite and actinolite dissolution in research and discovery in deep layers, which shows great HCl-H O at 100°C is close to the stoichiometric. 2 prospect of hydrocarbon exploring in deep layers. Basing on The reacted surfaces of actinolite are observed using newest exploring results and research, it can be proposed that: EPMA, HRTEM, SEM and XPS. The surface after reacted at ! There are two kind of sources, normal source rock and inner temperature <300ºC is quite different from that after reacted source resident liquid hydrocarbon cracking, which can at+300ºC. At temperature +300ºC, metal-hydrogen exchange provide hydrocarbon, causing the deep layer resource potential reaction is weak and the release rates of Si increases. HRTEM may be out of our expectation. " Deep-ultradeep layers and SEM studies indicate that a Fe (Al)-rich, Si-deficient layer onshore China are affected by several geological factors. In is formed at surface. Experiments prove that each metal– the deep layers of superimposed basins, there are carbonate, oxygen bond within the silicate structure breaks at a distinct volcanic and clastic reservoirs. # Large area of accumulation rate, which is affected by temperature. XPS and SEM-TEM can happen in carbonate rocks, clastic rocks and volcanic study indicates that the surface layer after reacted at 300- rocks in deep-ultradeep layers. The reserve abundance is not 400°C is not only amorphic, but also hydrated silicate, so high but the scale can be very large. !The exploring degree composed of Si-O-Si, Mi-OH-, and Mi-O bonds. This project in deep layer onshore China is low and the remaining resource is supported by the project of k[2013]01-062-014, SinoProbe- is high, it can be predicted that the deep layers onshore will 07-02-03, SinoProbe-03-01-2A and 2010G28. become an important replace area for the oil and gas industry of our country.

www.minersoc.org DOI:10.1180/minmag.2013.077.5.8

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Dolomitization process and its effect Carbon and Oxygen Isotopic on the behavior of trace elements in Compositions: How to Respond the carbonate rocks Lacustrine Environmental Factors in WENXUAN HU 1, 2, LICHAO WANG 1 Northwestern and Northeastern AND XIAOLIN WANG1, 2 China 1 School of Earth Sciences and Engineering, Nanjing HU XIAOLAN ZHAO QI University, Nanjing, 210093, P.R. China

2Institute of Energy Sciences, Nanjing University, Nanjing, College of Resource and Environmental Sciences, Lanzhou 210093, P.R. China University, Lanzhou, 730000, China *correspondence: [email protected] The origin of dolomite has been considered to be a long- standing enigma in sedimentary geology. It has been accepted The sediments, that 28 closed-lake sediments from Hoh that dolomitization of limestone by solutions with high Xil, 24 from Northeastern China, 99 surface sediments from Mg2+/Ca2+ ratio is one of the most important mechanisms to Lake Bosten, 31 from Ulungur and 26 from Heihai were produce dolomite. Therefore, understanding the geochemical collected to determine the '13C and '18O values and discussed behaviors of major and trace elements during dolomitization is the impacting factors to the '13C-'18O. The closure and vital towards deciphering the mysterious “dolomite problem”. residence time of lakes can influence the correlation between An example section is selected in this study of Geshan '13C and '18O. Mg/Ca in the bulk sediment indicates the profile of the middle Triassic age in the Lower Yangtze area, characteristic of residence time, Sr/Ca and Fe/Mn infer the China. This outcrop develops various carbonate rocks ranging salinity of lakes. Carbonate forming and types can influence from limestone, through dolomitic limestone and calcareous the '13C-'18O correlation. When carbonate content is less than dolomite, to dolomite. The carbonate series represent a 30%, there is no relationship both '13C and '18O, and no gradual increase in dolomitization degree. relationship between '13C and '18O. But more than 30%, The geochemical signatures of these carbonate rocks are carbonate content highly co-varies to '13C and '18O, and has well preserved as supported by two folds of evidence: (a) most high correlation between '13C and '18O also. Vegetation of the dolomites are micritic or fine-grained with planar-s in condition and primary productivity of lakes can influence the fabric, and (b) the Mn/Sr ratios of these samples are generally characteristic of '13C and '18O, and their co-varying. Organic less than 1. The average Sr concentrations of limestone, matter content (TOC) in the sediments is higher with more dolomitic limestone, calcareous dolomite and dolomite are terrestrial and submerged plants filling. When organic matter 1357.7 ppm, 271.2 ppm, 121.8 ppm and 99.9 ppm, comes from endogenous floating organisms and algae respectively; whereas the average Mn concentrations are 15.37 (C/N<6), '13C value is heavy. '13C is in -4~0‰. '13C is in the ppm, 17.46 ppm, 27.85 ppm and 44.09 ppm, respectively. range of -4~8‰ as organic matter comes from diatom Therefore, the Sr concentration of carbonate rocks decreases (C/N=6~8). '13C is in the range of -8~-4‰ as organic matter with increasing dolomitization processes. However, the Mn from aquatic and terrestrial plants (C/N>8). concentration shows an opposite variation trend. Previous studies suggest that, in the dolomite lattice, Sr mainly substitutes Ca sites. However, our observations show that the Sr concentration exhibits a non-linear decrease along with the decrease of CaO content during dolomitization. This reflects that, apart from the substitution of Ca, Sr exists in dolomite in other forms, such as in the crystal defects, or in fluid inclusions. In addition, compared with the published Sr concentration in microbial dolomite precipitated in culture experiments, our results ruled out the possibility of bacterial origin for the dolomite in this report.

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Rapid bulk rock decomposition by Fluid inclusion study of Maoping W ammonium fluoride (NH4F) in open- deposit, southern Jiangxi province vessels by an elevated digestion R.M. HUA AND D.Q. HU temperature State Key Laboratory of Mineral Deposit Research, Nanjing 1, 1 1 University, Nanjing 210093, China ZHAOCHU HU *, WEN ZHANG , QION NI , 1 2 YONGSHENG LIU , RICHARD M. GASCHNIG , LIAN 1 1 The Maoping tungsten deposit is a large W-Sn- ZHOU AND LAISHI ZHAO polymetallic deposit discovered recently in southern Jiangxi 1State Key Laboratory of Geological Processes and Mineral province. It comprises two types of ore-bodies, i.e. quartz-vein Resources, China University of Geosciences, Wuhan type and greisenized-granite type. The present paper studies 430074, China the fluid inclusions in quartz and topaz occurring in 2Department of Geology, University of Maryland, College wolframite-quartz-veins, which mainly includes Park, Maryland 20742, USA microthermometry and Laser Raman analysis. Besides, the homogenization temperatures of fluid inclusions in wolframite Complete dissolution is essential to achieve accurate were also determined under an infra-red microscope. Result analytical results for geological samples. Hydrofluoric acid is shows that fluid inclusions in both quartz and topaz are mainly

the most effective mineral acid for breaking up strong Si-O of liquid-rich two-phase aqueous solution (H2O-NaCl), in -2 bonds to form SiF6 ions in acidic solution. In this study, addition of small amount CO2-bearing three-phase aqueous decomposition technique using the neutral solid compound solution in quartz. The homogenization temperatures from NH4F in open vessel (Savillex Teflon vial) has been quartz show wider variation range and can be divided into two investigated for multi-element analysis of different types of main periods, indicating two stages of ore precipitation. The

rock reference materials. The higher boiling point (260 °C) of CO2-bearing three-phase inclusions have similar NH4F allows for an elevated digestion temperature in open homogenization temperatures to the higher temperature period vessels, which enables the decomposition of refractory phases. of above inclusions, but lower salinities and different It took 1-1.5 h for Zr to be completely recovered in GSP-2 at homogenizing ways. Fluid inclusions in wolframite have 250 °C, which is 12 times faster than using conventional highest homogenization temperatures and salinities, whereas closed-vessel acid digestion at 190 °C (high-pressure PTFE those in topaz also show high homogenization temperatures � digestion bomb). Unlike in NH4F-assisted high pressure acid and salinities, and narrow variation range. The characteristics digestion, our results clearly indicate that adding HNO3 of homogenization temperatures and salinities from fluid severely inhibited the digestion capabilities of NH4F for inclusions in quartz reveal the multiple-stage of ore-forming refractory minerals such as zircon in open vessel. The most process and the complexity of fluid evolution. It is concluded outstanding advantage of the new method is that the digestion from this fluid inclusion that the early-stage boiling and late- can be performed in a conventional Savillex Teflon vial stage mixing is probably the major mechanism of formation of instead of using a high pressure PTEF digestion bomb. wolframite-quartz-vein type ore in the Maoping deposit. Moreover, the NH4F"open-vessel acid digestion is not hampered by the formation of insoluble fluorides, which represent another important advantage of this new sample

decomposition method. Similar to HF and HNO3, ultra-pure

NH4F can be produced using a conventional PFA sub-boiling purification system, and it does not induce new interference species in ICP-MS analysis. It is also worth emphasized and this reagent is removed by taking the sample to dryness, which is important to keep the total dissolved solid of the final solution presented to the instrument low. The developed

NH4F"open-vessel acid digestion has been successfully applied to the digestion of a series of international geological reference materials. This simple, effective, and comparatively safe dissolution method shows a great potential for the digestion of geological samples.

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Silicon isotope fractionation between The mercury in the low latitude the upper and lower mantle of the Holocene peat profile associated with Earth monsoon variation FANG HUANG1, ZHONGQING WU2 AND SHICHUN HUANG3 JING HUANG, LIMIN ZHOU AND XIANGMIN ZHENG1 1CAS Key Laboratory of Crust-Mantle Materials and 1Key Laboratory of Geographic Information Science, Ministry Environments, School of Earth and Space Sciences, of Education, East China Normal University, Shanghai, USTC, Hefei 230026, China ([email protected]) China, 200241, correspondence author:Limin Zhou, 2Laboratory of Seismology and Physics of Earth's Interior, ([email protected]) School of Earth and Space Sciences, USTC, China. 3Department of Earth and Planetary Sciences, Harvard Mercury is key trace metal in earth surface system. The University, 20 Oxford Street, MA 02138, United States gasous elemental Hg takes over 90% and has a long resident time in atmosphere. Mercury in ice core has been researched As the second most abundant element in rocky planets, Si for a long time. The total element Hg changes from exhibits limited isotopic variations among different chondrite interglacier and glacier period, although there exits the groups [1]. The !30Si of Bulk Silicate Earth (BSE), estimated argument on the driving process. The thermal lability of based on basalts and peridotites, is higher than chondritic mercury in peat bog could be considered as an important value. The heavier Si of BSE is proposed to be balanced by paleoclimate proxy. The 1.3m peat core at the Caohai Lake 30 lighter Si in the Earth’s core. In detail, a range of ! SiBSE- was collect. By the AMS dating age the core covered 3.8 ka 30 ! SiChondrite, from 0.04 to 0.20‰, has been reported [e.g., 1-3]. up to 9.4 ka. The total mercury concentration with the Kempl et al [4] reported Si isotopic fractionation coefficient different temperature heating pretreatment associated with the between metal and silicate under high P-T conditions, and organic carbon analysis including the stable carbon isotope they concluded that “the core contains between 11 and 29 wt% analysis. The results show the mercury concentration is 30 30 Si” depending on the value of ! SiBSE-! SiChondrite. Such high consistent with the organic carbon variation. The clear Si content in the core conflicts with seismic observations. fluctuation at 8.2 ka and 4.3 ka could be detected. The We calculated equilibrium fractionation factors of Si mercury concentration variation is consistent with the solar isotopes at high P-T conditions using density functional theory radiation change from Dongge Cave which is closed to this for mantle silicate minerals. Our calculations reveal significant peat core site. Compared to the mercury in the ice core, by this Si isotope fractionation among mantle minerals with different result, the mercury in peat at low latitude takes the different Si coordination numbers (CN), especially between Mg- variation pattern from the high latitude region, which implies perovskite (CN=6) and olivine polymorphs (CN=4). Using our that the deposition pattern with the climate change varies with ab initio calculation and the magma ocean crystallization the latitude. model of [5], the lower mantle, dominated by perovskite, is estimated to have lower !30Si (by ~0.1‰) than the upper mantle, dominated by olivine polymorphs. If such primordial Si isotope heterogeneity between the upper and lower mantle is not completely destroyed through the Earth’s history, !30Si of BSE could be lighter than that inferred based on peridotites and basalts which are derived from the shallow upper mantle. Consequently, it does not require an unrealistically high Si content in the core.

[1] Savage and Moynier (2013) EPSL. [2] Chakrabarti and Jacobsen (2010) GCA. [3] Georg et al (2007) Nature. [4] Kempl et al (2013) LPSC. [5] Walter, M.J. and R.G. Trønnes, EPSL, 2004.

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Unmasking enigmatic xenolithic Carbon isotopic evidence for methane eclogites: Progressive metasomatism release during the end-Permian mass on a key Roberts Victor sample extinction *JIN-XIANG HUANG1,2, W. L. GRIFFIN1, Y. GREAU1, JUNHUA HUANG1, LIDAN LEI1, GENMING LUO1,2 AND N. J. PEARSON1 AND S. Y. O’REILLY1 QUNFENG ZHOU3 1CCFS/GEMOC, Macquarie University, Sydney, Australia 1State Key Laboratory of Geological Processes and Mineral (*correspondence: [email protected]) Resources, China University of Geosciences, Wuhan 2Institute of Geology and Geophysices, China Academey of 430074, China Sciences, Beijing, China 2State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan Extensive studies of xenolithic eclogites have generated 430074, China two contradictory hypotheses about their origin. One regards 3Institute of Geophysics & Geomatics, China University of the eclogites as deep-seated magmatic rocks, while the other Geosciences, Wuhan 430074, China regards them as basaltic components of subducted oceanic slabs. To test the hypotheses, it is essential to find out if the The largest mass extinction in the Phanerozoic that samples being studied actually carry primary information. occurred mainly at the end-Permian about 252 Ma ago, Previous work on Roberts Victor eclogites (South Africa) eliminated ~90% of marine invertebrate species and ~70% of divided the samples into Types I and II. Type I eclogites show terrestrial vertebrate species [3]. The succedent recovery of the sequential degrees of metasomatism by melts/fluids in the whole marine ecosystem lasted for more than 5 Ma [2] This carbonatitic-kimberlitic spectrum; Type II eclogites may be mass extinction was known to be accompanied by large the protoliths of Type I. perturbations in the global carbon cycle. However, the cause- Progressive metasomatism inferred from studies of the and-effect relationship between the mass extinction and the whole eclogite suite, has now been revealed within one sample global carbon cycle perturbation remains unclear [1]. RV07-17. Four zones (progressively 1, 2, 3, and 4) are Here we analyzed paired carbonate and organic carbon distinguished using the compositions of garnets. From Zone 1 isotopic composition at the biostratigraphically-constrained to Zone 4, the microstructure becomes less equilibrated; Ganxi section which was located in northern deep water basin secondary minerals and fluid inclusions become abundant; that attached to the Yangtze carbonate platform during the P- 13 pyrope content of the garnets increases gradually; cpx shows Tr transition. The ! Ccarb underwent two episodes of negative progressive enrichment in MgO. The cross-cutting pattern shifts. The first one, from ~1.5‰ to 0‰, occurred before the 13 strongly suggests that Zone 1 represents an early stage of the main mass extinction horizon. The corresponding ! Corg also metasomatism, and Zone 4 the latest stage. show a negative shift from ~-25‰ to ~-28‰. The second The garnets of Zone 1 have flat REE patterns from Lu to shift, from ~1‰ to -1‰, occurred at the lower Triassic, which Sm, but a strong depletion in the LREE. Toward Zone 4, the might correspond to the second episode identified at the relative abundance of the MREE of the garnets drops Meishan section (Xie et al, 2007). However, the 13 significantly, giving smoother patterns. A large cpx grain in corresponding ! Corg shows a distinct positive shift from ~- 13 Zone 1 shows a strong depletion in the LREE, but the 28‰ to ~-25‰. During the extinction interval, the ! Ccarb 13 LREE/MREE of the cpx increases from Zone 1 to Zone 4. increased to ~1‰, and the ! Corg kept relatively constant. From Zone 1 to 4, 87Sr/86Sr of cpx increases along with Sr In addition to the two episodes of general negative shifts, content; !18O of the garnet decreases from ~8.5 to ~6.0 ‰ as it is interesting to note that there are two intervals 13 the MgO content increases. characterized by sharp negative shifts in ! Ccarb. One of them These observations indicate that the eclogite was was found to occur around the P-Tr boundary, in which the 13 metasomatized by Mg-rich melts/fluids, changing through ! Ccarb declined from +1‰ to -1.3‰ within 3-cm thick strata. time from carbonatitic to more kimberlite-like. The On the basis of recent high-resolution dating (Shen et al, metasomatism has swept away all original information on 2011), this shift produces a variation rate as high as 80‰/Ma 13 compositions, making it nearly impossible to define a for the ! Ccarb, suggesting the occurrence of huge methane protolith. To know the origin of the xenolithic eclogites, and release. to use them as evidence for different dynamic scenarios, the Our data in Ganxi section indicate that the significant 13 13 least metasomatised samples must be studied more than has negative shifts in ! Ccarb and ! Corg were not caused by the been done previously. mass extinction. Episodic release of methane, combining with other events, might have occurred during the mass extinction interval, which could make a contribution to the extinction and environmental perturbation.

[1] Berner (2002) Proc Nat Acad Sci USA 99, 4172-4177. [2] Chen & Benton (2012) Nature Geoscience 5, 375-383. [3] Erwin et al (2002). Boulder Geol. Soc. Amer. 356, 363-384. [4] Shen et al (2011) Science 334. [4] Xie (2007). Geology 35, 1083-1086.

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Replacement of authigenic and Comparative characterization of detrital pyrrhotites by marcasite and charcoals prepared from pyrolysis pyrite in cold-seep sediments offshore and hydrothermal carbonization and SW Taiwan their water extractable organic KO-CHUN HUANG1 AND WEI-TEH JIANG1 carbon 1Department of Earth Sciences, National Cheng Kung R.X. HUANG1*,W.C. HOCKADAY1, B.L.T. LAU1, University, Tainan, Taiwan., R.O.C. X.W. LU2AND D. JACK3 [email protected]; [email protected] 1 Department of Geology, Baylor University, Waco, Texas,

USA (*correspondence:[email protected]) Complex formation sequences of pyrrhotite, marcasite, 2 Department of Civil and Environmental Engineering, and pyrite in two 5-m piston cores of muddy sediments University of South Carolina, Columbia, USA offshore southwestern Taiwan were investigated by FESEM- 3Department of Mechanical Engineering, Baylor University, EDS-EBSD techniques. The cored sites were characterized by Waco, Texas, USA a shallow sulfate methane interface at ~2 meters below seafloor and located in a ridge area (Fengliao Ridge) with Understanding the properties and the environmental cold-seep activities. behavior of charcoals produced from biomass is important Two intriguing types of iron-sulfide microtextures were within the context of carbon sequestration and sustainable identified for the sediments. Firstly, sub-millimeter stacks of agriculture. The present study compares the physicochemical detrital pyrrhotite crystals were largely replaced by pyrite and properties of different types of chars and dissolved organic minor marcasite. Later formed platy crystals (lathy section) of carbon (DOC) derived from them, as a means of making pyrrhotite developed from the edges of such stacks and were qualitative inferences about their stability and organo-mineral locally replaced by marcasite and pyrite as well. The second interactions in soils. type involved the occurrence of millimeter-sized iron-sulfide Chars were synthesized by slow pyrolysis at 250 °C and nodules. The nodules had a core made of aggregates of lathy 500 °C and hydrothermal carbonization (HTC) at 250 °C grains consisting of a mixture of pyrite and minor marcasite, using wheat straw as feedstock. The charcoals were and were fringed with pyrrhotite crystals and carbonate. characterized by solid-state 13C nuclear magnetic resonance Regardless of the microtextural differences, the marcasite spectroscopy (NMR) and thermogravimetric analysis (TGA). EBSD data collected within single lathy grains invariably A higher proportion of aromatic carbons (78%) were formed exhibited six intensity clusters aligned parallel to the long axes in char pyrolyzed at high temperature than low temperature of the lathy grains in the {010} pole figure and two intensity pyrolysis (47%) and HTC charcoals (51%). Statistical clusters oriented perpendicular to the same axes in the {100} correlations between 13C NMR peak areas and mass loss data pole figure, and displayed an orientation relationship of from TGA demonstrated that the aromatic carbons were {100}Mrc || {0001}Po, {010}Mrc || {1000}Po, and {001}Mrc || mostly oxidized at temperature above 350 °C, while the alkyl {1 10}Po whenever the pyrrhotite relicts were present. No carbons being oxidized at temperature below 350 °C. This specific orientation relationships between pyrite and pyrrhotite suggests that the formation of aromatic structures was or marcasite were detected. All of the pyrrhotites had a Fe/S responsible for the thermal stability of charcoal. The leaching atomic ratio of ~0.87. of labile organic carbon from chars was simulated using The formation of marcasite occurred through epitaxial aqueous Soxhlet extraction. Leaching released a relatively replacement of detrital or diagenetic pyrrhotite and was related small proportion of the charcoal carbon as DOC (<3%). The to the oxidation of pyrrhotite that led to chemical changes in HTC charcoal leached more DOC than pyrolysis charcoal, and microenvironments. Relatively reducing pore fluids with low low-temperature pyrolysis charcoal leached more DOC than flux of hydrogen sulfide were favorable for the authigenesis of high-temperature pyrolysis charcoal. Spectroscopic pyrrhotite. The multiple stages of phase replacement and characterization (proton and 13C liquid NMR and UV-vis) of precipitation were suggestive of temporal variations of redox the DOC impied that they are mostly low molecular weight conditions and hydrogen-sulfide activities associated with neutral molecules (e.g., sugars and alcohols). Batch adsorption fluctuations of the sulfate-methane interface in the region. experiments showed no significant adsorption of the DOC onto kaolinite and goethite over a wide range of pH in the presence of 10 mM NaNO3, which suggests that adsorption potential of the DOC onto common soil minerals is low.

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Effects of glycine on oligomerization A newly identified microorganism of methionine under high affecting the N cycle: Ammonium temperature and high pressure oxidation in iron reducing soils R. HUANG1*, Y. FURUKAWA1 , AND T. KAKEGAWA1 SHAN HUANG1 AND PETER R. JAFFE1* 1Guraduate school of Science, Tohoku Univ., Japan 1Department of Civil and Environmental Engineering, (*correspondence: [email protected]) Princeton University, Princeton, NJ, [email protected] (* presentimng author) Abiotic polymerization of amino acids seems to be an + important process for the formation of the first life. Previous A novel anaerobic ammonium (NH4 ) oxidation process studies have implied the importance of pressurized conditions coupled with iron reduction was first noted in a forested (1, 2) + for the production of longer peptides, simulating the riparian wetland in New Jersey . In this reaction, NH4 is conditions of marine sediments [1, 2, 3]. These previous oxidized using ferric iron as the electron acceptor. Either this studies also suggest the skepticism about the formation of same pathway, or a very similar one, was also reported in a biological reactor (3), and a tropical rainforest soil (4) and peptides composed of plural amino acids, showing a variety in (3) reactivity of amino acids. In this study, we investigated the coined Feammox . Here we focus on characterizing the microbiology oligomerization of methionine and glycine under the responsible of the Feammox process described for our conditions of high temperature and high pressure (at 175°C, (1,2) previous study site , through an anaerobic incubation 150 MPa, and 0-96 hours). experiment and using 16S rDNA PCR-DGGE and qPCR Methionine and glycine were used for representatives of - analysis. Production of both nitrite (NO2 ) and ferrous iron each low and high reactive amino acid, respectively. Starting were measured repeatedly during incubations when soil materials were solid methionine or solid methionine mixed slurries were supplied with iron oxide (ferrihydrite or goethite) with solid glycine, water, aqueous ammonia, or ammonium and ammonium chloride. Significant changes in the microbial hydrogen carbonate. The additives other than glycine (water, community were observed during the incubation, and one of aqueous ammonia, and ammonium hydrogen carbonate) are the dominant microbial species (an uncultured simulated decomposition products of glycine. Each starting Acidimicrobiaceae bacterium A6), belonging to the material was sealed into a gold capsule. Then, high Acidimicrobiaceae family, similar to Ferrimicrobium temperature and pressure conditions were applied using a test- acidiphilum (with 92% identity), is believed to be responsible tube-type autoclave system. After these experiments, for this Feammox pathway. This novel bacterium is experimental products were analyzed with a high performance considered to be autotrophic since its activity increased liquid chromatograph connected to a mass spectrometer. substantially when inorganic carbon was supplied. Through The rates of methionine decomposition and methionine- qPCR analysis using specific designed primers, Acidimicrobiaceae peptide formation were increased with additives. These rates bacterium A6 was also found at a storm- water detention pond, which has similar high NH + and iron were especially increased in samples containing aqueous 4 oxide content, indicated that the Feammox pathway might be ammonia and ammonium hydrogen carbonate, suggesting that widespread in soil environments. ammonia promote both the production rates of peptides and The Feammox process provided denitrifiers and anammox the decomposition reactions of methionine. The difference in - bacteria with the necessary NO2 under this anaerobic reaction rates might have been caused by the difference in pH incubation, and achieved total nitrogen loss via denitrification as suggested in a previous study [4]. Our results suggest that and anammox pathways. Therefore, Feammox may be an amino acids of lower reactivity may have been activated by important process in the nitrogen cycle in soil environments amino acids of higher reactivity, and then promoting peptide under oxygen limited conditions, and reveals a new linkage formation composed of plural amino acids. Such new finding between these two significant biogeochemical cycles (iron and may have happened commonly in prebiotic environments. nitrogen cycle).

[1] Ohara et al (2007), Orig Life Evol Biosph 37, 215–223. [2] [1] Clement et al (2005) Soil Biol. Biochem. 37, 2323-2328. Otake et al (2011), Astrobiology 11, 799-813. [3] Furukawa et [2] Shrestha et al (2009) Soil Sci. 174,156-164. [3] Sawayama. al (2012), Orig Life Evol Biosph 42, 519–531. [4] Sakata et al J. (2006) Biosci. Bioeng. 101, 70-72. [4] Yang et al (2011) (2010), Geochim Cosmochim Acta 74 6841–6851. Nat. Geosci. 5, 538-541.

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Sm/Nd ratio of the Earth Studies on the characteristics and SHICHUN HUANG1, STEIN B JACOBSEN1 mechanism of a heavy haze episode in AND SUJOY MUKHOPADHYAY1 Jiangsu Province, China 1 Department of Earth and Planetary Sciences, Harvard X.X. HUANG, T.J. WANG* AND J.L. ZHU University ([email protected]) School of Atmospheric Sciences, Nanjing University, Nanjing The composition of Bulk Silicate Earth (BSE) provides an 210093, China ([email protected] important “roadmap” understanding the thermal evolution, (*correspondence: [email protected]) mass flow and the structure of Earth’s mantle. Athough it has been known since 1960s that the BSE composition is overall Autumn is one of the periods that poor air quality not chondritic [1], it is assumed that the refractory elements in frequently occurs in Jiangsu [1]. In this study, the the Earth are present in chondritic proportions relative to each characteristics and mechanism of a regional haze episode were other [2], which is the basis of many models about the investigated in late October 2012 over Jiangsu. The analysis compositions of BSE and depleted mantle (DM) [e.g., 3]. was conducted with the observational concentrations of air 147 143 The Sm- Nd isotopic system has been used as a pollutants (PM10, PM2.5, and CO) in 13 cities, visibility data in “backbone” to estimate the compositions of BSE and DM. 5 cities, meteorological elements (relative humidity, wind This is because both Sm and Nd are refractory elements, and speed, air temperature, precipitation in surface, upper air all chondrites have essentially the same Sm/Nd ratio (within soundings, and synoptic situation), fire locations from FIRMS, ±2%) [e.g., 2, 4]. BSE is assumed to have chondritic Sm/Nd and trajectories from the numerical models of HYSPLIT. The and 143Nd/144Nd ratios. However, this assumption is challenged northern cities suffered more heavily with the highest hourly 142 3 by recent Nd studies [4, 5]. Specifically, Boyet and Carlson PM10, PM2.5, CO, ratio of PM2.5 to PM10 exceeding 0.50mg/m , [4] reported ~20 ppm 142Nd/144Nd difference between Earth 0.45mg/m3, 3.5mg/m3, and 0.9, respectively. The lowest and ordinary chondrites. Although this difference could be of hourly visibility was below 5km in the 5 cities. Backward nucleosynthetic origin [6, 7], it has also been attributed to trajectories accompanied with fire spots exhibited that either early silicate differentiation of a chondritic Earth, pollutants from large areas of biomass burning during the occurred within 30 Myrs after the Earth’s formation [4], or to harvest season mixed with local anthropogenic emissions a superchondritic BSE, which has a Sm/Nd ratio 6% higher contributed to this event. The degradation of air quality in than the chondritic value [5]. northern cities was mainly caused by emissions from biomass Here we re-examine published data, and found that: burning, while the southern cities were affected by the mixed 1. There is ~50 ppm 142Nd/144Nd variation in chondrites, and emissions. Synoptic condition was another factor, especially it is correlated with nucleosynthetic anomalies in 135Ba, calm and weak wind, and relatively high temperature before 144Sm and 148Nd. Consequently, the 20 ppm 142Nd/144Nd rainfall. difference between Earth and ordinary chondrites must reflect nucleosynthetic origin; [1] Deng et al (2011) Atmos. Res. 101, 681-691. 2. Possible nebular processes are unable to significantly fractionate Sm/Nd ratio; consequently, it is unlikely that the Earth accreted from a nebular reservoir with a superchondritic Sm/Nd ratio; 3. Our analyses of the 147Sm-143Nd isotopic systematics of continental crust and DM suggest that BSE, or the accessible portion of BSE under the “hidden reservoir” hypothesis, has a near-chondritic Sm/Nd ratio.

[1] Wasserburg et al (1964) Science. [2] Jacobsen and Wasserburg (1984) Earth Planet Sci Lett. [3] McDonough and Sun (1995) Chem Geol. [4] Boyet and Carlson (2005) Science. [5] Caro et al (2008) Nature. [6] Ranen and Jacobsen (2006) Science. [7] Andreasen and Sharma (2006) Science.

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Vanadium Distribution in A reference Earth model for the heat Environmental Samples Surrounding producing elements and associated the Slag Dump in Panzhihua, Sichuan geoneutrino flux province, P.R.China Y. HUANG1*, V. CHUBAKOV2, F. MANTOVANI2, 1 1 1, 2 1 1, 2 1 R.L. RUDNICK AND W.F. MCDONOUGH HUANG YI *, ZHANG WEI , NI SHIJUN , CHEN YING AND ZHONG LICHUN 1University of Maryland, College Park, MD 20742, USA 1 (*correspondence: [email protected]; Department of Geochemistry, Chengdu University of [email protected], [email protected]) Technology, Sichuan, PRC, [email protected] (* 2Università degli Studi di Ferrara/ INFN, Ferrara, Italy presenting author) 2 ([email protected],[email protected]) Applied Nuclear technigues in Groscience Key Laboratory of

Sichuan Proviance, PRC Geoneutrinos are electron antineutrinos emitted by beta- minus decays of naturally occurring radionuclides (e.g., heat Million tons of metallurgical slag bearing abundant producing element (HPEs), namely U, Th and K). The recent vanadium (V) was piled outside along Jinshajiang river, geoneutrino experimental results from KamLand [1] and upstream of Yangtze river. Vanadium distribution in water, Borexino [2] detectors reveal the usefulness of analyzing the sediment and soil samples sur-rounding the slag dump was Earth’s geoneutrino flux, as it provides a constraint on the studied. The results showed that from the slag dump to the strength of the radiogenic heat power and this, in turn, downstream of the Baguanhe river, vanadium content and the provides a test of compositional models of the bulk silicate pH value gradually decreased for water samples, and also Earth (BSE). This flux is dependent on the amount and vanadium content of sediment samples gradually decreased. distribution of HPEs in the Earth’s interior. Soil vanadium near the slag dump is usually higher than the We have developed a geophysically-based, three- background value of soil in Sichuan province, and the soil dimensional global reference model for the abundances and with the highest value was collected from the slag dump area. distributions of HPEs in the BSE [3]. The structure and It is apparent that slag piling has brought a certain degree of composition of the outermost portion of the Earth, the crust pollution to the surrounding environment. and underlying lithospheric mantle, is detailed in the reference model, this portion of the Earth has the greatest influence on the geoneutrino fluxes. The reference model combines three existing geophysical models of the global crust and yields an average crustal thickness of 34.4±4.1 km in the continents and 8.0±2.7 km in the oceans, and the total mass (in 1022 kg) of oceanic, continental and bulk crust is 0.67±0.23, 2.06±0.25 and 2.73±0.48, respectively. In situ seismic velocity provided by CRUST 2.0 allows estimates of the average composition of the deep continental crust by using new and updated compositional databases for amphibolite and granulite facies rocks, in combination with laboratory ultrasonic velocities measurements. An updated xenolithic peridotite database is used to represent the average composition of continental lithospheric mantle. Monte Carlo simulation is used to predict the geoneutrino flux at selected locations and to track the asymmetrical uncertainties of radiogenic heat power due to the Figure 1. Vanadium concentration and pH values of water log-normal distributions of HPE concentrations in crustal samples along the Baguanhe river rocks.

[1] Gando et al (2013) arXiv: 1303.4667. [2] Bellini et al (2013) arXiv: 1303.2571. [3] Huang et al (2013) G-Cubed, doi: 10.1002/ggge.20129.

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Limitations of isotopic and elemental A constant flux of diverse anaerobic signatures of oxygenic thermophilic endospores into cold photosynthesis: A possible solution? marine sediments AXELLE HUBERT1, 2*, FRANCES WESTALL1, CASEY HUBERT,1* EMMA BELL,1 JÚLIA DE REZENDE,1 ALEXANDRE SIMIONOVICI2, CLAIRE ROLLION-BARD3 CHINA HANSON,1 ANA SUÁREZ-SUÁREZ,1 IAN HEAD,1 AND NATHALIE GRASSINEAU4 ALEXANDER LOY,2 ALBERT MÜLLER,2 CHRISTIAN 2 3 3 1 BARANYI, TIMOTHY FERDELMAN, MAREN NICKEL, CBM, CNRS, 45071 Orléans, France (*correspondence VERONA VANDIEKEN,3 CAROL ARNOSTI,4 VOLKER [email protected]) 5 6 6 2 BRÜCHERT, KAI FINSTER, KASPER KJELDSEN, ISTerre, Grenoble, France 6 3 AND BO BARKER JØRGENSEN CRPG, CNRS, 54500, Vandoeuvre les Nancy, France 4RHU L, Egham, Surrey TW20 0EX, United Kingdom 1School of Civil Engineering & Geosciences, Newcastle University; (*[email protected]) The appearance of oxygenic photosynthetic bacteria is 2Dept of Microbial Ecology, University of Vienna recognised to be one of the major processes involved in the 3Max Planck Institute for Marine Microbiology rise of oxygen in Earth’s atmosphere. This process permitted 4Dept of Marine Sciences, University of North Carolina the development of more complex aerobic lifeforms. 5Department of Geological Sciences, Stockholm University However, the timing of the appearance of oxygenic 6Center for Geomicrobiology, University photosynthesis and that of the oxygenation of the Earth are still debated [1] and constraining the event remains a Microorganisms have been repeatedly discovered in challenge. environments that do not support their metabolic activity. In a Initially, oxygenic photosynthesis must have appeared in striking example of this, experiments to determine the very localized zones [2] before having a global influence. temperature optima for sulfate reduction in permanently cold Certain factors can influence the isotopic and elemental Arctic marine sediments revealed that metabolic rates were signatures of early oxygenic photosynthesis at the local level. greatest in sediment that was incubated above 50°C. This These include (i) overlapping ranges of 13C isotopes for response was distinct from that associated with the local cold- oxygenic photosynthetic and heterotrophic signatures, (ii) adapted microbial community (that catalyzed much lower mixing of signatures in complex, multicommunity microbial rates associated with a 20°C optimum) and is explained by mats, and (iii) diagenetic reduction of potential redox sensitive the germination of endospores of diverse thermophilic transition metals and trace elements by heterotrophs and Clostridiales that lie dormant in marine sediments but can geochemical processes caused by the predominantly (still) rapidly mineralize organic matter by hydrolysis, fermentation, anaerobic environment. and sulfate reduction upon induction at 50°C. Identifying and We aim to disentangle the complex isotopic and elemental quantifying misplaced organisms such as thermophilic signatures of photosynthetic bacterial biofilms and cells in endospores can reveal rates and vectors of cell dispersal that sedimentary cherts ranging from 3.5 to 1.9 Ga. We are shape natural microbial diversity and biogeography. In this conducting a systematic in situ investigation characterizing case, endospore germination experiments that incorporated 35S individual microbial mats so as to understand the diffrences sulfate radiotracer were combined with a 210Pb sediment age between fossilized anoxygenic and oxygenic photosynthetic model to enable the estimation of a stable supply of mats. We chose to focus on individual microbial mats as they thermophilic bacteria into the sediment at a rate exceeding 108 record the composition and concentration of transition metals spores per square meter per year. Genomic comparisons and trace elements, as well as C and S isotopic signatures on a indicate that the closest relatives to these and other misplaced very fine, local scale. thermophilic spores are found in warm subsurface petroleum We hope to be able to understand the fine scale isotopic reservoir and ocean crust ecosystems, suggesting that seabed and elemental signatures of photosyntheitc oxidation in our fluid flow from deep biosphere environments may be samples so as to contribute to the overall delineation of the transporting thermophiles into the cold ocean. These proposed record of Earth’s oxyenation. mechanisms for the passive dispersal of microbial cells may thus connect very different provinces of the biosphere and [1] Farquhar J., Zerkle A.L., & Bekker A. (2011), lithosphere, and could be broadly influencing microbial Photosynthesis Research 107, 11-36. [2] Anbar A.D., et al community composition in the marine environment. (2007), Science 317, 1903-1906.

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Coupled climate-geochemical Geological history of 4-Vesta: modeling of the connections between 26Al-26Mg dating on eucrites and break-up of Rodinia, weathering of continental flood basalts, snowball G. HUBLET1, V. DEBAILLE1, J. WIMPENNY2 glaciations and the strontium cycle AND Q-Z. YIN2 1 1 1 G-Time, Université Libre de Bruxelles, Brussels, Belgium, LUCIE HUBERT-THÉOU , GRANT C. COX , 2 3 ([email protected]) GUILLAUME LEHIR , YVES GODDÉRIS , 2 4 1 Department of Geology, University of California, Davis, CA, YANNICK DONNADIEU , GALEN P. HALVERSON , 5 1 USA ANDRÉ POIRIER AND LINDSAY NELSON

1 McGill University, Earth and Planetary Sciences Eucrites and diogenites are belonging to a department, 3450 University Street, Montreal (Qc), H3A magmatic series coming from 4-Vesta. Eucrites are basaltic 2A7, Canada ; ([email protected]) rocks, while diogenites are ultrabasic cumulates. We used the 2 IPGP, 1 rue Jussieu, 75238 Paris cedex 05 ; ([email protected]) 26Al-26Mg chronometer for precise dating of eucrites and 3 Geoscience Environnement Toulouse, UMR 5563, CNRS- diogenites and revealing the geological history of 4-Vesta. Université Toulouse III, 14 avenue Edouard Belin, 31400 Basaltic eucrite textures suggest a formation and rapid Toulouse, France ; ([email protected]) cooling on the surface in lava flows or dikes while cumulative 4 Laboratoire des Sciences du Climat et de l'Environnement, eucrites evidence deeper and slower cooling. This study UMR 8212, CNRS-CEA-UVSQ, Orme des Merisiers, reveals that those two types of eucrites belong to two different 91191 Gif/Yvette ; ([email protected]) age populations and cannot be used together for external 5 Université du Québec à Montréal, GEOTOP-UQAM, isochrons. Ages obtained for basaltic eucrites suggest a CP 8888, Montréal (Qc), Canada ; formation of the eucrite crust during a short and ancient period ([email protected]) of magmatic activity on 4-Vesta between 4564 to 4563 Ma. Disturbance observed for the 26Mg*/24Mg ratio in plagioclase Isotope records of marine seawater composition (e.g. '13C, fraction in one basaltic eucrite (Y-792510) suggest also a 87Sr/86Sr) display significant variability at the end of the metamorphism episode likely related to shock. Precambrian, in particular associated with the break-up of the Results obtained for the cumulative eucrites show younger Rodinia supercontinent and spanning the Cryogenian snowball ages compared to the basaltic type. This suggests that some Earth events ca. 716 and 635 Ma. Here we explore the time inner parts of Vesta were still warm until ~4560 Ma. Ghosh at interval 950–630 Ma to address the long-term evolution of the al. [1] show 26Al decay is probably the heating source for Neoproterozoic seawater chemistry and climate and to Vesta differentiation and basaltic eucrite magmatic activity, investigate perturbations to the Earth-system over this period. and may have also kept the mantle hot during a few Ma [2], We apply GEOCLIM, a powerful coupled climate- explaining the slow cooling rate evidenced by the younger age geochemical model to test the effect of the breakup of the of cumulative eucrites. supercontinent Rodinia and the emplacement and subsequent Finally, our incapacity to date diogenites with the 26Al-26Mg weathering of Large Igneous Provinces (LIPs: Willouran- chronometer suggests a younger age for them (< 4560 Ma) Gairdner, Guibei, Gunbarrel anf Franklin events) on the Diogenite are thought to be formed in intrusion within the carbon cycle. The strontium cycle and its isotopes are eucrite crust during a second period of magmatic activity on 4- implemented in the model in order to assess the influence of Vesta [3, 4], probably generated by the remelting of the lithologic and paleogeographic changes on the weathering of magma ocean cumulates [5, 6]. This remelting cannot be continental silicates and climate. To this end, new 87Sr/86Sr related to the 26Al decay because at this time, the 26Al was data from marine carbonates of various Neoproterozoic completely extinct. A mantle overturn could be a process to successions (Northwestern Canada, Eastern Greenland, explain this remelting event. Svalbard, Siberia and Saudi Arabia) were produced to build a more complete Sr isotope record spanning the Neoproterozoic [1] Ghosh A., et al (1998) Icarus, 134, 187-206. [2] Zhou Q., and to provide initial conditions in our simulations. In et al (2013) GCA, 110, 152-175. [3] Barrat J.A., et al (2010) addition, Sr and Nd isotopes ratios were measured on GCA, 74, 6218-6231. [4] Yamaguchi A., et al (2011) Journal Neoproterozoic mafic rocks and Nd isotopes on fine-grained of Geophysical Research, 116, E08009. [5] Barrat J.A. (2004) sediments to track the timing of emplacement and weathering MAPS, 39, 1767-1779. [6] Barrat J.A., et al (2008) MAPS, 43, of the major LIP relative to glaciations. 1759-1775.

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Redox controls on diagenetic Melt-inclusion evidence for a incorporation of rare earth elements CO2-rich mantle beneath the western in fossil fish teeth branch of the East African Rift C.E. HUCK1*, T.VAN DE FLIERDT1, S.M. BOHATY2, T.R. HUDGINS1*, S.B. MUKASA2 AND A.C. SIMON1 3 S. HAMMOND AND IODP EXPEDITION 318 SCIENTISTS 1 Department of Earth and Environmental Sciences, University 1Imperial College, London SW7 2AZ UK of Michigan, Ann Arbor, MI, USA 2Ocean and Earth Science, NOC, Univ. of Southampton, (*correspondence: [email protected]) Southampton, SO14 3ZH UK 2Department of Earth Sciences, University of New Hampshire, 3The Open University, Walton Hall, Milton Keynes MK7 6AA Durham, NH, USA UK

CO2 in the mantle may moderate the generation of low Fossil fish teeth and skeletal debris are considered one of silica magmas. Here, we present data from olivine-hosted melt the most robust archives for reconstructing Nd isotope ratios inclusions that are consistent with a carbonated mantle source of seawater in the geological past, and have been widely used beneath the western branch of the East African Rift. to fingerprint individual water masses and trace their Twenty-four samples were collected from the Virunga distribution through time. Little systematic work, however, province of the East African Rift. These rocks are silica- has been done to verify the robustness of this proxy in understaturated potassic lavas (kamafugites) with 38-45 wt%

marginal settings and under varying bottom-water and SiO2 and K2O/Na2O>1. We quantified the abundances of

sedimentary redox conditions. major, minor, and trace elements, as well as the volatiles H2O,

IODP Expedition 318 recovered Paleogene drillcores from CO2, F, S, and Cl in olivine-hosted melt inclusions from five

offshore of the East Antarctic margin (Site U1356; whole-rock samples. The H2O and CO2 concentrations range 63°18.61'S, 135°59.94'E). Strata of early Eocene age (~48 to from ~0.3 to 2.5 wt% and ~30 to 9,950 ppm, respectively. The

~49 Ma) deposited in a shelf environment during the warmest CO2 values are consistent with molecular dynamics

period of the Cenozoic - the Early Eocene Climatic Optimum simulations for the solubility of CO2 in MORB and may (EECO) - show striking cyclical variations between oxidised represent less degassed melt[1]. The melt inclusions have and reduced conditions. Since Site U1356 is located proximal elevated Li concentrations (up to 117 ppm) and B/Be ratios to the Tasman Gateway and the EECO is of particular interest (>10) relative to MORB (Li ~3 to 4 ppm, B/Be ~2 to 4). for palaeoceanographic reconstructions during the early Two plausible sources of the volatiles are fluids evolved Paleogene greenhouse, we investigated the robustness of the during paleo-subduction, and fluid exsolved from the melting Nd isotope signal in fish debris deposited during the early of a mantle plume. Published Nd, Hf, Sr, and Os data for rocks Eocene at this site. across the EAR western branch suggest mixing of two Individual fish teeth were picked from the >125%m metasomatized mantle sources as the source of these magmas, fraction of washed bulk sediments. Comparison between fully requiring previous fluid-mantle interaction[2]. Elevated Li and reductively cleaned samples and samples only cleaned with B concentrations measured in arc magmas have been used as a water and methanol yielded the same Nd isotopic composition, fluid tracer to investigate the role of fluid additions to the and hence the latter cleaning procedure was used for the mantle wedge. As such, volatiles subducted by the closure of majority of the samples. All samples were dissolved in HCl, the Mozambique Ocean during the Pan-African orogeny are a

aliquoted for major and trace element analyses, and subjected plausible source for the elevated CO2 and H2O. This scenario to a standard two stage ion chromatography. is consistent with evidence for long-term storage of volatiles isotope ratios were determined using a Nu Plasma MC-ICP- in the mantle[3]. Other potential sources include ancient MS and major and trace element data, including rare earth subducted slabs pooled in the lower mantle and fluids released element patterns, were obtained on an Agilent 7500a from a partially melting mantle plume. Radiogenic and noble quadrupole ICP-MS. gas isotope studies may be required to fully distinguish the Preliminary data show systematic variation in the Nd sources of the mantle metasomatism. isotopic composition of fish teeth extracted from reduced and oxidised sediments. We will evaluate these findings in the [1] Guillot and Sator (2011) GCA 75, 1829-1857. [2] context of a more comprehensive data set, including main and Rosenthal et al, (2009) EPSL 284, 236-248. [3] Pettke et al, trace element data, and discuss the implications of varying (2010) EPSL 296, 267-277. redox conditions at the sea floor on the incorporation and preservation of seawater Nd isotopes in fossil fish teeth.

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Subcontinental lithospheric mantle Dissolved metals in redox-state zero: and mantle plume controls on crustal A gap in thermodynamic databases PGE abundance: A case study of W. HUMMEL Palaeogene magma conduits from Laboratory for Waste Management, Paul Scherrer Institut, Western Scotland, UK 5232 Villigen, Switzerland ([email protected])

1 H. HUGHES, I. MCDONALD, A.C. KERR Dissolution of metals like silver is usually considered 2 + - AND A.J. BOYCE solely as oxidative dissolution Ag(s) , Ag + e . 1School of Earth and Ocean Science, Cardiff University, UK Whereas the solubility of zero-valent mercury is well CF10 3AT. (*correspondance: [email protected]) known [1], experimental data about the solubility of other 2Scottish Universities Environmental Research Centre, East metals like silver is scarce [2, 3]. The explicit equilibrium , Ag(aq) Kilbride, Glasgow, UK G75 0QF. Ag(s) although published and discussed in [2], is not included in any A strong correlation can be demonstrated between plume thermodynamic database. The same is true for Hg(aq). magmatism, ancient cratonic lithosphere, and the occurrence The myth that heavy metals are “insoluble” seems to be so of magmatic sulphide Ni-Cu-PGE deposits [1]. Such deposits powerful that dissolved metal atoms do not exist in are typically located proximal to Archaean craton margins. A geochemical considerations. This blind spot of chemical highly desirable combination of plume-related mafic/ equilibrium thermodynamics has consequences: (1) The ultramafic igneous systems and Archaean cratons, underlain calculated “solubility abyss” of heavy metals under reducing by their associated subcontinental lithospheric mantle (SCLM) conditions does not exist. (2) “Unclear differences” in keel, occur within the North Atlantic Igneous Province experimental data sets and strange model parameters are due (NAIP). Significant mineralization has been discovered in the to the ignorance of zero-valent metal species. western portion of the NAIP (e.g. Skaergaard and Paleogene (1) In the field of radioactive waste disposal solubility macrodykes [2,3]). Therefore, the British Palaeogene Igneous limits of contaminants are important safety issues. In the case Province (BPIP) is potentially the most prospective PGE of metals like silver, conventional model calculations lead to a province in Western Europe. “solubility abyss” under strong reducing conditions. There, This research focuses on the Scottish sector of the BPIP. silver metal is the thermodynamically stable phase and the Isolated platinum group mineral occurrences are documented concentration of dissolved silver virtually drops to zero. This on the Isles of Rum, Mull and Skye, but with limited is an artefact due to the omission of Ag(aq). assessment of its relationship to the province as a whole. To (2) Experimental determinations of the solubility of silver assess the geochemical inputs of asthenospheric (plume) vs. sulphide, Ag2S(s), lead to large differences between data sets lithospheric ‘reservoirs’, a temporal and spatial evaluation of in acidic solutions. “The reason for this is unclear” [4]. PGE abundance across the region must be adopted. This study However, these differences can be explained by considering

incorporates the Paleoproterozoic Scourie dyke swarm, Ag(aq) and assuming that the data sets have been measured Caledonain lavas and small-scale intrusions, mantle xenoliths, under slightly different redox conditions. Measurements of the and Palaeogene lavas and magma conduits. solubility of gold in water have been interpreted in terms of Whole-rock grab samples were analysed for major and extremely strong AuOH(aq) complex formation [5]. Assuming trace elements by ICP-OES and ICP-MS and NiS fire assay a solubility of zero-valent gold similar to Ag(aq) the with ICP-MS analysis to determine PGE and Au abundances. experiments can be interpreted as governed by the formation Whole-rock PGE+Au concentrations from the 2.4 Ga Scourie of Au(aq). Dyke swarm suggest no major removal of PGE from mantle Experimental data or good estimates for Au(aq), Cu(aq), ‘reservoirs’ at this time, leaving residual Archaean SCLM as Ni(aq), Pd(aq), Pt(aq) are needed to fill the database gap. ‘fertile’. Permian dyke-hosted lherzolite xenoliths are in support of the shallow mantle remaining ‘fertile’ during this [1] Clever et al (1985) J. Phys. Chem. Ref. Data 14, 631-680. period, and may have undergone some degree of subduction- [2] Kozlov & Khodakovskiy (1983) Geochem. Inter. 20, 118- related enrichment of Au during Caledonian orogenesis. 131. [3] Dobrowolski & Oglaza (1963) Nucleonika 8, 79-81. Lithogeochemical indicators (e.g. Cu/Pd ratio) highlight the [4] Stefánsson & Seward (2003) Geochim. Cosmochim. Acta occurrence of both S-saturated and -unsaturated magma 67, 1395-1413. [5] Stefánsson & Seward (2003) Geochim. batches across the BPIP, however there is no clear correlation Cosmochim. Acta 67, 1677-1688. with MgO, which may infer variable Cu/Pd of parental magmas instead. Pd/Ir suggest variable coeval SCLM contamination.

[1] Begg, G. C. et al 2010. Econ. Geol., 105, 1057-1070. [2] Andersen, J. C. Ø. et al 1998. Econ. Geol., 93, 488-509. [3] Holwell, D.A. et al (2012). Mineral. Dep., 47, 3-21.

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Structure of carbonate-silicate melts Three styles of delamination found at high P-T conditions using in situ beneath the western United States X-ray diffuse scattering EUGENE HUMPHREYS1*, BRANDON SCHMANDT2 AND 3 1 2 ALAN LEVANDER DANIEL HUMMER , ABBY KAVNER AND CRAIG MANNING3 1University of Oregon, Eugene Oregon, USA 97403 1 (*correspondence: [email protected]) Department of Earth and Space Sciences, University of 2University of New Mexico, Albuquerque NM, USA 87131 California Los Angeles, Los Angeles, CA 90095, 3Rice University, Houston Texas, USA 77251 ([email protected]) 2 Department of Earth and Space Sciences, University of Strong seismic heterogeneity imaged across the western California Los Angeles, Los Angeles, CA 90095, U.S. upper mantle implies the occurrence of segmented ([email protected]) 3 subduction, active upwelling associated with Yellowstone, and Department of Earth and Space Sciences, University of small-scale convection across most of the area. When put California Los Angeles, Los Angeles, CA 90095, in geologic context, we ([email protected]) recognize three types of small-scale convective Carbonatites are an important class of mantle-derived downwelling. (1) Most of magmas that may play a fundamental role in mantle meta- the fast structures are somatism and carbon cycling. To examine compositional thought to be fragments dependence of melt structure in the CaO-MgO-CO -SiO 2 2 of Farallon lithosphere system, we performed in situ X-ray scattering experiments in emplaced at the base of the Paris-Edinburgh press at HPCAT (Advanced Photon North America during Source) using compositions along the CaCO -CaSiO (Cc- 3 3 Laramide-age flat-slab Wo) and CaCO -Mg SiO (Cc-Fo) joins. Both systems exhibit 3 2 4 subduction. Their tabular simple eutectic melting over a wide pressure range, with no form suggests a subsolidus decarbonation reactions [1,2]. Charges were loaded o delamination style of using the setup of Yamada et al [3], and held at ~1800 C and detachment from North ~40 kbar while energy dispersive X-ray scattering spectra America. Associated were recorded at each of eleven scattering angles to achieve -1 magmas probably reciprocal space coverage up to q=32 Å . involves melting of ascending asthenosphere, hydrated basal The presence of both Cc and Wo in quenched charges North America, and Farallon ocean crust. (2) Another type of confirms the retention of CO . Pair distribution functions 2 downwelling is most reasonably explained as a delamiation- (PDF) reveal local atomic structure of the liquid and, when style detachment of North American lithosphere. An normalized to the calcite-liquid PDF, provide a measure of association with volcanism suggests basalt infiltration and silica polymerization. Results suggest that CaCO3 forms an 2- eclogite loading of the delaminated lithosphere, i.e., thermo- ionic liquid with intact CO ions, in agreement with previous 3 chemical convection. (3) A third delamination type is inferred results [4,5]. Silicate melts show a clear signal at 1.6 Å, from the young uplift of granitic batholiths that have a corresponding to Si-O in SiO 4- tetrahedra. Both Wo-bearing 4 geochemical signature for garnet-rich restites. and Fo-bearing compositions also show a strong signal at 3.3 Examples include delaminations related to the Columbia Å, corresponding to Si-Si in polymerized silica. Thus, in the River Basalt eruptions (involving delamination types 1 and 3, presence of carbonate, even liquid orthosilicates contain silica in conjunction with arrival of the Yellowstone plume) and the polymers. The extent of polymerization moderately increases ignimbrite flareup (type 1), and uplift of the southern Sierra with carbonate content along both joins, suggesting that Nevada (3 and maybe 1), Colorado Plateau margin (2) and the carbonate has a significant influence over the chemistry of Transverse Ranges (1). In many cases, magmatism molten silicates at mantle conditions. appearently is an integral part of delamination; it both enables [1] Huang & Wyllie (1974), EPSL 24, 305-310. [2] Huang et mechanical detachment through the emplacement of lower al (1980), Am. Min. 65, 285-301. [3] Yamada et al (2011), crustal sills, and caused asthenosphere return flow. A general Rev. Sci. Instr. 82, 015103. [4] Waseda & Toguri (1977), consequence of these delaminations is a remaking continent Metall. Trans. B 8B, 563-568. [5] Benmore et al (2010), Phys. by driving mass exchange between continent and underlying Rev. B 82, 224202. mantle, and internal segregation of the continent.

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Evolution of chemical and physical Clinopyroxene and its relationship to properties of mixed arc magmas rapdily erupted, carbonate-rich MADELEINE C S HUMPHREYS1, MARIE EDMONDS2, magmas in Calatrava, Spain 3 4 THOMAS CHRISTOPHER AND RICHARD BROOKER 1,2 1 EMMA R. HUMPHREYS-WILLIAMS* TERESA JEFFRIES 1Department of Earth Sciences, University of Oxford, South AND KEN BAILEY†2 Parks Road, Oxford, OX1 3AN, UK 1 Earth Sciences, Natural History Museum London, SW7 5BD ([email protected]) 2 (correspondance: [email protected]) Department of Earth Sciences, University of Cambridge, 2 Earth Sciences, University of Bristol, Bristol, BS8 1RJ Downing Street, Cambridge, CB2 3EQ, UK †deceased 3Montserrat Volcano Observatory, Flemmings, Montserrat,

West Indies Rapidly erupted alkaline, ultramafic magmas such as those 4Department of Earth Sciences, University of Bristol, Wills occuring in intraplate settings offer a unique opportunity to Memorial Building, Queen’s Road, Bristol, BS8 1RJ, UK understand lithosphere structure and rock petrogenesis. Such

volcanism erupts rapidly from the mantle, entraining a dense Many intermediate arc magmas arise as a result of load of xenolithic material forming up to 30% of the rock [1]. mingling between mafic and silicic melts that may be The discovery of abundant examples of carbonate-rich genetically unrelated. Recharge involving mafic melts is volcanism containing magmatic carbonate in association with commonly cited as the trigger for new or renewed eruptive ultramafic silicate glass [2], highlights the role of carbonate episodes, and a mechanism for rejuvenating stalled silicic and carbon-rich fluids in the formation of these magmas. crystal mush in the mid-crust. This process has a profound However, a comprehensive understanding of the petrogenesis effect on the chemical and physical properties of the whole of such magmas remains elusive and petrological observations volcanic system. Using geochemical microanalysis and of variably resorbed, originally euhedral crystals are just one textural observations, it is possible to identify distinct indication of a complex magmatic history. compositions of minerals and glass that reflect different Clinopyroxenes from a rapidly-erupted carbonatitic tuff in elements of the volcanic system. There is abundant evidence Calatrava, Spain have been analysed for their major and trace of physical and chemical contamination of the silicic magma element composition. Clinopyroxenes are ideal candidates for on the micron-scale during mingling, and entrainment of understanding melting processes as they host a significant deeper plutonic material. Disequilibrium reaction textures and quantity of trace elements and the partitioning behaviour is overgrowth rims indicate direct contact between crystals from relatively well characterised. The tuff has a wide textural the silicic magma and the mafic melt, including sieved range of clinopyroxene which occurs alongside calcium- plagioclase, coarse breakdown textures in hornblende and carbonate within fresh melilititic silicate glass. Within glassy clinopyroxene overgrowth on quartz and orthopyroxene. lapilli, carbonate occurs as globules and also as a matrix Anomalous glass compositions overlap with the residual glass between lapilli fragments. of some mafic enclaves, indicating mingling between mafic Clinopyroxenes have Mg# 0.68-0.80 and span a wide and silicic melts. Microlite/ microphenocryst compositions range of major element compositions. Clinopyroxenes do not overlap with mafic enclave mineral compositions, suggesting overlap with the major element composition of mantle incorporporation of mafic crystals into the host magma. xenolith-derived clinopyroxenes erupted in similar volcanism During ascent, the mingled magma experiences volatile in Calatrava, suggesting that no clinopyroxene originates from exsolution and decompression crystallisation. We discuss and the disaggregation of mantle xenoliths. present evidence for the chemical variations that take place in Melts calculated to be in equilibrium with a range of the magma during ascent through the volcanic system, clinopyroxenes illustrate the variation of the melt composition including the controls on changing oxidation state due to before and up to eruption. Our data suggest that large degassing and crystallisation, and evidence for the exsolution ‘xenocrystic’ clinopyroxenes relate to the early stages of of a dense brine. We also draw together constraints on the magma formation. Resorption of once euhedral crystals can be timescales of these processes and consider their effects on the attributed to disequilibrium resulting from changes in physical properties of the evolving magma. We discuss the composition of the melt prior to eruption. implications of these findings for our understanding of

andesite petrogenesis and eruption triggering and style. [1] Humphreys, et. al, (2010), Geology 38 (10), 911-914, [2] Bailey & Kearns (2012), Min. mag. 76(2), 271-284.

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The influence of urbanisation on Redox and nutrient cycling in a late forest soils: Comparing variability Mesoproterozoic sea and mobility of potentially toxic K.F. HUSBAND1,2*, S.W. POULTON1, R. GUILBAUD1, elements and carbon sequestration A.D. ROONEY3 AND D. SELBY4 between urban regions in Scotland 1Sch. Earth & Env., Uni. of Leeds, Leeds, LS2 9JT, UK (*correspondence: [email protected]) and Bulgaria 2Sch. Civil Eng. & Geosci., Newcastle Uni., Newcastle upon 1 2 Tyne, NE1 7RU, UK ANDREW HURSTHOUSE *, VANYA DOICHINOVA AND 3 2 Dept. Earth & Planet. Sci., Harvard Uni., Cambridge MA MIGLENA ZHIYANSKI 02138, USA 1 School of Science, University of the West of Scotland, 4Dept. Earth Sci., Uni. of Durham, Durham, DH1 3LE, UK Paisley, PA1 2BE, UK (*[email protected]) 2Forest Research Institute, Bulgarian Academy of Sciences, A growing body of evidence suggests that, during the so- 132 “Kliment Ohridski” Blvd., 1756 Sofia, Bulgaria called ‘boring billion’ (~1.8-0.8 Ga), the global ocean was ([email protected]; [email protected]) characterised by widespread euxinia along productive

continental margins, with deeper waters that remained The process of urbanization creates unique urban ferruginous. In detail, however, evidence for euxinic ecosystems and urbanized soils. Due to high pollution load conditions in continental margin settings is extremely scarce and the dynamic effect of climate change in the urban in the early Neoproterozoic (~1.0-0.75 Ga), with most environment, green infrastructure comes under increasing evidence instead suggesting an expansion of ferruginous stress. The great potential is for urban forest areas to offer a conditions. In addition, little is known about the detailed significant contribution in mitigation of CO at a small scale, 2 nature of ocean chemistry in the late Mesoproterozoic, prior to but little is known about the interaction with urban soils, this apparent change in global ocean chemistry. Ocean redox increasingly recognized as a sink for inputs of urban conditions potentially exert a strong control on nutrient pollutants. Our study looked at a number of forest soil sites cycling, thus influencing organic carbon production and along rural-urban gradiets in Glasgow, Scotland and the Sofia burial, and, in turn, environmental oxygen levels. However, Region, Bulgaria. the lack of detailed studies on late Mesoproterozoic We compared soil properties with carbon stocks, nutrient successions means that little is known about redox-driven availability and potentially toxic element loads. In urban soils nutrient feedbacks at this time, and hence controls on of Sofia carbon stocks varied between 80 - 125 tC ha-1 and for environmental conditions towards the end of the ‘boring Glasgow 76 - 120 tC ha-1, with non-urbanized control sites: 53 billion’ remain poorly understood. - 103 tC ha-1 for the Sofia region. The tree carbon stock, was Here, we present an integrated study of Fe-S-C higher in non-urbanized sites, because of higher tree density in systematics and P cycling in the 1.1 Ga Taoudeni Basin of these plots. The results for aboveground biomass carbon stock Mauritania. Earlier in the succession, we find that euxinia was in urban sites varied between 34.5 - 61.7 tC.ha-1 for Sofia and prevalent in mid-depth waters, with deeper waters being 45.2 - 60.8 tC.ha-1 for Glasgow and in Non-Urban sites: 33.9 - ferruginous. However, there is less evidence for euxinia 67.5 tC.ha-1, and 57.3 tC.ha-1 respectively. further up the succession and instead ferruginous conditions We obtained strong correlations between mobile forms of became more widespread. Ferruginous conditions throughout Cu, Zn, Pb, Cd in urban soils and a number of soil parameters the succession are commonly characterized by enhanced (pH, CEC and texture). The mobility related to soil pH (and organic C burial, suggesting that the development of euxinic OM for Cu) agreeing with other work in the cities. The most conditions was not simply driven by organic C availability. To mobile soil fraction was found for Cd (33%). The assessment provide further insight, we utilize P speciation and S isotope of health status of oaks tree vegetation based on indices data, which together shed new light on environmental defoliation of crown and changes in color do not correlate condtions during this crucial interval that marks the final significantly with the bioavailable concentration of PTEs in stages of several hundred million years of apparent the soils. Carbon sequestraton relates strongly to management environmental stasis. activity and the influence of PTE content is obscured.

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High throughput analysis of mining Indirect dating of the samples by LA-ICP-MS Guadalupian-Lopingian Boundary ROBERT W HUTCHINSON1 DAVID PRICE2 M.H. HUYSKENS*, Y. AMELIN1, R.S. NICOLL1,2 AND ALEX CHRIST3 AND I. METCALFE3 1New Wave Research (a division of ESI), 8 Avro Court, 1Research School of Earth Sciences, The Australian National Ermine Business Park, Huntingdon, PE29 6XS, United University, 142 Mills Road, 0200 Acton, ACT, Australia. Kingdom. ([email protected]) (*[email protected]) 2PerkinElmer LAS (UK) Ltd, Chalfont Road, Seer Green, 2Geoscience Australia, Canberra, Australia. Beaconsfield, Bucks HP9 2FX , UK. 3Earth Sciences, University of New England, Australia. ([email protected]). 3Bureau Veritas Australia Pty Ltd. 58 Sorbonne Cres Canning The Guadalupian-Lopingian Boundary (GLB) is defined Vale Perth WA 6155. ([email protected]) by the first occurrence of the conodont species Clarkina postbitteri postbitteri and currently interpreted to be 259.8±0.4 Mining operations rely on fast turnaround of precise and Ma [1]. The Global Section and Point (GSSP) for accurate analysis of rock and soil sampled from the field. A this boundary at Penglaitan, south China has detailed fossil large mine can supply up to 100,000 samples to the analytical and chemostratigraphy information available, but services per month, each requiring extensive sample unfortunately neither magnetostratigraphy nor geochronolgical preparation for analysis by XRF for composition analysis and studies were successful at the GSSP section. solution analysis-ICP-MS for trace elements. The latter is We have correlated the GSSP section to a terrestrial typically performed by sample digestion in aqua regia, which sequence in the southern Sydney Basin, Australia using C- has cost, health and safety and disposal considerations. isotope stratigraphy and present high-precision U-Pb Here we describe methodology and results for the trace geochronology for five samples covering the Wilton element analysis of XRF discs by laser ablation ICP-MS. This Formation to the Erins Vale Formation tied to C-isotopic methodology removes the solution digestion sample values [2] of the drill core Bunnerong DDH 1. Based on C- preparation and its associated costs and risks. Furthermore, the isotope stratigraphy the GLB in the southern Sydney Basin is sample type is highly stable long-term and can be recalled for interpreted to correlate with the boundary between the repeat analysis without the need for specialist storage. Thirroul Sandstone and the Woonona Coal. Based on two Overall, the LA-ICP-MS methodology represents bracketing U-Pb ages (256.47±0.14 Ma and 258.04±0.54 Ma, improvement in cost, manpower, throughput and risk when 51 m above and 65 m below the GLB respectively) the age of compared to solution ICP-MS analysis. the GLB is interpreted to be ~ 257.5 Ma. These new dates can be used to constrain the age of the mid-Capitanian mass extinction. This extinction was previously interpreted to coincide with the GLB, but more recent work suggests a prolonged extinction episode in the mid-Capitanian with different biota becoming extinct at different levels. There is no current consensus on placement of the mass extinction. One of the suggestions is that it occurred at the base of the Jinogondolella granti zone coinciding with a major sea-level regression [3]. This regression is recorded in the southern Sydney Basin by an erosive contact between the Erins Vale Formation and the Thirroul Sandstone. This regression is dated at ~ 258 Ma.

[1] Gradstein et al (2012) GTS 2012, pp. 1176. [2] Birgenheier et al (2010) P3 286, 178-193. [3] Wignall et al (2009) Journal of the Geological Society, London 166, 655- 666.

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Assessment of accuracy and precision Volcanic acid-sulfate analogs for for IRMS by standard material early Mars JONG-YEON HWANG1!, BO-KYONG KIM, WON-SEOK LEE, BRIAN HYNEK1,2*, THOMAS MCCOLLOM1, MIN-SEOB KIM AND JIN-SEOK HAN KARYN ROGERS3 AND EMMA MARCUCCI1,2 1Environmental Measurement & Analysis center, NIER, 1Lab. for Atmospheric and Space Physics, University of Environmental Research complex, Gyeongseo-dong, Seo- Colorado, 3665 Discovery DR, Boulder, CO 80303 USA gu, Incheon Metropolitan City, 404-708, 2Department of Geological Sciences, University of Colorado, KOREA.(!corespondence : [email protected]) 399 UCB, Boulder, CO 80309 USA 3Geophysical Laboratory, Carnegie Institution of Washington, The setup of optimum condition for IRMS Washington, DC 20015 USA As a result of this study, carbon isotope composition was very precise and accurate in a narrow range as well as a wide Owing to Mars’ prolonged history of volcanism, high heat range of sample weight. The measured '13C value that was flow, and copious surface water, we assume abundant within the certified value ± 2- had the minimum carbon hydrothermal systems persisted for significant time periods. contents in which EMA-P1 and EMA-P2 is 102.107 %g and Life on Earth may have originated in a similar setting and 116.879 %g, respectively. Although nitrogen and sulfur isotope assessment of putative hydrothermal systems on Mars is composition was less precise and accurate than carbon, the paramount to assessing the planet’s geochemical history and nitrogen content(18.650 %g) and sulfur content(27.839 %g) astrobiological potential. To this end, we have been assessing already had been within the certified value ± 2-. The variation Earth and putative Mars hydrothermal systems through of isotope composition was also investigated by the fieldwork, lab experiments, geochemical modeling, and

fractionation factor *applied that would explain the stability for remote sensing. Fieldwork at active basaltic volcanoes in '13C, '15N and '34S value. We suggest that carbon, nitrogen Central America and Hawaii was used to document and sulfur isotope composition need to be determined by geochemical pathways of acid-sulfate alteration and resultant considering several factors; accuracy of '13C value and mineralogy. These results were correlated with environmental precision of '13C value, peak height ratio and fractionation parameters (T, pH, fluid:rock ratio) to define the controls on

factor *applied. alteration pathways. We find that extremely acidic pH and high temperature fumalores rapidly alter the parent lithology Discussion of Results into S, amorphous Si, with occasional crusts of gypsum. Study on stable isotopes in contaminants is a relatively Moderately acidic (pH of about 4) fumaroles lead to abundant new concept with high potential of transforming a monitoring- gypsum, natroalunite, Si, and Al-smectites. Mildly acidic and based research paradigm into a more advanced one. In this cooler fumaroles produce calcite and gypsum. Correlated study, a brand-new stable isotope analyzer was used and laboratory experiments and geochemical modeling on whole accuracy and precision were evaluated using carbon and basalts and individual mineral components have further nitrogen reference materials to establish the optimal analytical defined the controls of acid sulfate alteration over a broad condition. And also, we can conclude that the analysis of range of conditions and we found that high fluid:rock and stable isotopes in environment using a stable isotope analyzer temperatures lead to rapid dissolution of primary minerals and is a promising new method for identifying the sources of the liberated cations lead to a range of sulfates, amorphous Si, contaminants. and hematite concretions. Remote sensing data from Mars reveals discrete locales of minerals indicative of acid-sulfate [1] Jong-Yeon Hwang et al (2012) NIER-RP2012-143, pp.1- alteration and some were undoubtedly hydrothermal in origin. 52. [2] Bo-Kyong Kim et al (2012) J. of the Korean society Our terrestrial studies provide a conceptual framework for for Environmental Analysis, 15(4), pp. 245-255. [3] Z. interpreting the paleoconditions of ancient martian SHARP (2007) Principles of Stable Isotope Geochemistry . hydrothermal systems, where we are able to use the alteration mineralogy to infer the likely conditions of formation. Further, we have characterized the microbiology within active terrestrial volcanoes. While the hottest and lowest pH sites have minimal biomass, the moderately acidic and cooler fumaroles have diverse endolithic communities of photo- and heterotropic aerobes and anerobes.

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High rates of carbon oxidation Impact of Fe speciation in the aquifer through dissimilatory manganese sediments on ferric (hydr)oxide reduction in sediment of Ulleung precipitation at the Changwon Basin in the East Sea research site, Korea JUNG-HO HYUN1, SUNG-HAN KIM1, JIN-SOOK MOK1, S. P. HYUN*, H. S. MOON, P. YOON, K. HA HYE-YOUN CHO1, VERONA VANDIEKEN2 AND B.-G. CHAE AND BO THAMDRUP3 Korea Institute of Geoscience and Mineral Resources 11Hanyang University, Marine Sciences and Convergent (KIGAM), Daejeon 305-350, Korea (*Correspondence: Technology, Korea; [email protected] [email protected]) 2University of Oldenburg, Germany; verona.vandieken@uni- oldenburg.de Ferric (hydr)oxide precipitation can control the mobility of 3University of Southern Denmark; ([email protected]). contaminants and redox conditions in an aquifer. The impact of Fe speciation on the kinetics of ferric (hydr)oxide Dissimilatory iron reduction plays an important role in the precipitation at the sediment-groundwater interfaces was oxidation of organic carbon in continental sediments, whereas studied using the sediment samples collected from the large contributions from dissimilatory manganese reduction KIGAM research site in Changwon, Korea. The research site are only known from a few locations characterized by a very is on unconsolidated, Quaternary floodplain deposits by the high Mn content. There are very few experimental studies of Nakdong River. Sets of sediment samples were collected at these processes in deep sea sediments. As a contribution to varying depths and locations within the research site. The filling this gap and obtaining a more detailed understanding of sediment samples were wet-sieved to the sand, silt, and clay the regulation of the processes in marine sediments, we fraction, and further used for the Fe speciation investigated experimetally the rates and relative importance of characterization. Different pools of Fe present in the sediment terminal electron acceptors in sediment from the slope and samples were selectively extracted using ferrozine, ammonium floor of the >2000 m deep Ulleung Basin in the East Sea. Our oxalate, dithionite-citrate-bicarbonate, and hydrochloric acid. experiments also tested the assumptions behind the methods. Chemical and mineralogical characterization of the sediment The contributions of Fe and and Mn reduction were samples were performed using X-ray fluorescence, X-ray detemined in anoxic incubations both indirectly by comparing diffraction, and electron microscopy. Also, Fe distribution total carbon oxidation rates from DIC production to the part of between the sediment and groundwater was modeled using the DIC production contributed by sulfate reduction, and directly field measured groundwater chemistry data and Fe speciation from the accumulation of Fe(II) and Mn2+ over time, with results. corrections for reduction coupled to reoxidation of reduced The results indicate alternating redox conditions along the sulfur species and for the adsorption of Mn2+. Rates obtained depth of the aquifer. The alternating redox pattern suggests by the two methods agreed closely, which indicates that the heterogeneities in the organic matter content and mineral stoichiometric assumptions behind the incubation approach composition within the aquifer, and seasonal and spatial are correct. variations in the groundwater table affected by the river water Dissimilatory Mn reduction accounted for ~50% of level changes. The different extraction methods resulted in anaerobic carbon oxidation at the deep basin site, which independently varying or even apparently conflicting trends as contained more than 2.5 wt% Mn, while the process was functions of depth, suggesting the different quantities of Fe in insignificant at the slope site, which was not enriched in Mn. the different pools. The field measured dissolved Fe(II) Here, sulfate reduction dominated with ~80% of anaerobic concentration in groundwater was up to a hundred mg/L with

carbon oxidation. Both the the diffusive O2 uptake in intact dissolved oxygen between 0.1 to 4 mg/L, depending on the cores and the depth-integrated DIC production from anoxic depth and spatial location. This study suggests the potential of incubations demonstrated very high rates of carbon oxidation ferric (hydr)oxide precipitation upon the infiltration of surface in these deep sediments. water high in dissolved oxygen, to act as a sink and source of Our results add the Ulleung Basin to the very small set of contaminants such as heavy metals and radionuclides, locations where dissimilatory Mn oxidation is important, and depending on the prevailing geochemical conditions within the demonstrate that this deep basin is a hotspot of benthic aquifer. The results of this study will be used as background mineralization, which can be related to the oceanographic information in studying the kinetics of ferric (hydr)oxide characteristics of the East Sea. precipitation.

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