DOCSLIB.ORG

Characterization of the Goethite-Hematite Ratio in Modern

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Characterization of the Goethite-Hematite Ratio in Modern Lehigh University Lehigh Preserve Theses and Dissertations 2017 Characterization of the Goethite-Hematite ratio in Modern and Ancient Soils in the Mid-Atlantic Region as a Paleoprecipitation Proxy Laura Audrey Thomasina Markley Lehigh University Follow this and additional works at: http://preserve.lehigh.edu/etd Part of the Environmental Sciences Commons Recommended Citation Markley, Laura Audrey Thomasina, "Characterization of the Goethite-Hematite ratio in Modern and Ancient Soils in the Mid-Atlantic Region as a Paleoprecipitation Proxy" (2017). Theses and Dissertations. 2711. http://preserve.lehigh.edu/etd/2711 This Thesis is brought to you for free and open access by Lehigh Preserve. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Lehigh Preserve. For more information, please contact [email protected]. Characterization of the Goethite-Hematite ratio in Modern and Ancient Soils in the Mid- Atlantic Region as a Paleoprecipitation Proxy by Laura Markley A Thesis Presented to the Graduate and Research Committee of Lehigh University in Candidacy for the Degree of Master of Science in Earth and Environmental Sciences Lehigh University May 2017 © 2017 Copyright Laura Markley ii Thesis is accepted and approved in partial fulfillment of the requirements for the Master of Science in Earth and Environmental Sciences. Characterization of the Goethite-Hematite ratio in Modern and Ancient Soils in the Mid- Atlantic Region as a Paleoprecipitation Proxy Laura Markley Date Approved Stephen Peters, Ph.D., Thesis Advisor Frank Pazzaglia, Ph.D., Committee Member Kenneth Kodama, Ph.D., Committee Member Dave Anastasio, Ph.D., Chairperson of Department iii ACKNOWLEDGEMENTS Many thanks to my thesis advisor, Steve Peters, for all of his advisement and support throughout these past 2 years. His guidance, knowledge, and enthusiasm has molded me into a much better scientist and I am deeply indebted to him for bestowing upon me some of his lab and key-figure making skills. Thank you for countless edits, discussions, and suggestions. Committee Members, Ken Kodama and Frank Pazzaglia. Ken’s patience and knowledge in developing these magnetic methods for soils despite numerous issues and Frank’s immaculate memory of all things related to soils are unmatched. I owe both of you my gratitude for your intellectual discourse and suggestions throughout this process. Soil Team Members, Matt McGavick and Cora Summerfield for assistance with data collection and analysis as well as providing me with data they collected for their respective projects. Collaborating with both Matt and Cora has been a pleasure. Past Soil Team Members, Jordan Dykman, Taylor Cummins, and Johanna Blake for their soil, data, and well-organized excel documents. Tammy Rittenour from Utah State University for OSL and IRSL dates. Mark Carter from the USGS for assistance in the field and intellectual discourse. George for fixing the basement furnace at a moment’s notice during a busy week. Udo Schwertmann and Ethan Hyland for essential background information for this study. For financial support, I thank the GIC and Earth and Environmental Science Department at Lehigh. iv TABLE OF CONTENTS List of Figures .......................................................................................................................... vii List of Tables ............................................................................................................................. xi Abstract ...................................................................................................................................... 1 1.0 Introduction .......................................................................................................................... 3 1.1 Intro to Paleoprecipitation Proxies ................................................................................... 3 1.2 Intro to Soils ..................................................................................................................... 3 1.3 Intro to Iron Oxide Formation ......................................................................................... 4 1.4 Goethite-Hematite (G/H) and Mean Annual Precipitation (MAP) ................................. 7 2.0 Site Location & Characterization ......................................................................................... 9 2.1 Soil Chronology ............................................................................................................. 10 3.0 Soil Processing and Methodology ...................................................................................... 14 3.1 Soil Sampling and Description ....................................................................................... 14 3.2 Particle Size Distribution Analysis ................................................................................. 14 3.3 Bulk Elemental Analysis & Weathering Intensity ......................................................... 14 3.4 Iron Oxide Crystallinity.................................................................................................. 15 3.5 Magnetic Goethite and Hematite Abundance ................................................................. 16 3.6 Application of Hyland et al.’s G/H to MAP Proxy ........................................................ 18 3.7 Application of Sheldon et. al’s CIW to MAP Proxy ...................................................... 19 4.0 Results ................................................................................................................................ 19 4.1 Soil Characterization ...................................................................................................... 19 4.1.1 Middle/Late Miocene .............................................................................................. 24 4.1.2 Middle Pleistocene .................................................................................................. 25 4.1.3 Late Pleistocene ....................................................................................................... 29 4.2 Predicted Mean Annual Precipitation (MAP) ................................................................ 34 5.0 Discussion .......................................................................................................................... 36 5.1 Predicted Paleoprecipitation with Time ......................................................................... 36 5.2 Comparison with other Indices....................................................................................... 38 5.3 Deposition of Sediments vs. Onset of Pedogenesis ........................................................ 40 5.4 Presence of Gleying ....................................................................................................... 41 5.5 Influence of Organic Matter ........................................................................................... 42 5.6 Influence of Hydrology and Water Table Fluctuations .................................................. 44 v 5.7 Impacts of Parent Material Composition on G/H ........................................................... 44 5.8 Total Dithionite-Extractable (DCB) Iron Threshold ...................................................... 46 5.9 Use of Magnetic Methods to Determine G/H................................................................. 47 6.0 Conclusions ........................................................................................................................ 49 References ................................................................................................................................ 52 Appendices ............................................................................................................................... 58 Appendix 1. Extended Procedures ....................................................................................... 58 Particle Size Distribution Analysis ................................................................................... 58 Bulk Elemental Analysis .................................................................................................. 58 Iron Oxide Crystallinity.................................................................................................... 59 Appendix 2. Particle Size Distribution Analysis (PSDA) Data ........................................... 60 Appendix 3. FeO/FeD Values .............................................................................................. 63 Appendix 4. Major Elements (% By Mass) ......................................................................... 66 Appendix 5. Sample Demagnetization ................................................................................. 67 Appendix 6. G/H, CIW, & Predicted MAP .......................................................................... 75 Supplementary Figures ............................................................................................................. 77 Vita ........................................................................................................................................... 80 vi LIST OF FIGURES Figure 1: Diagram modified from Stucki et al. (1988), showing the formation of Fe(III) oxide precipitates, goethite and hematite, as a function of different climatic factors and processes. Fe(III) oxide precipitate formation in soils is a competitive pathway and is dependent on climatic variables
Load more

Recommended publications
  • Nonsteady-State Dissolution of Goethite and Hematite in Response to Ph Jumps: the Role of Adsorbed Fe (III)
    Water-Rock Interactions, Ore Deposits, and Environmental Geochemistry: A Tribute to David A. Crerar © The Geochemical Society, Special Publication No.7, 2002 Editors: Roland Hellmann and Scott A Wood Nonsteady-state dissolution of goethite and hematite in response to pH jumps: the role of adsorbed Fe (III) SHERRY D. SAMSON* AND CARRICK M. EGGLESTON Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071 USA * Author to whom correspondence should be addressed ([email protected]). Present address: Department of Geological Sciences, University of Colorado, Boulder CO 80309 USA Abstract-Dissolution transients following downward pH jumps to pH 1from a variety of higher pH values during dissolution in a mixed-flow reactor contain information about dissolution processes and mechanisms. Despite more than an order of magnitude difference in steady-state dissolution rates, the transients for goethite (a.-FeOOH) (this study) and hematite (a.-Fe203) (Samson and Eggleston, 1998) are similar in their pH dependence and relaxation times. After a pH jump, the time required to reach a new steady state is 40 to 50 hours. The amount of excess Fe released in the transients (defined as the amount of Fe released in excess of that released in an equivalent length of time during steady-state dissolution at pH 1) increases with in- creasing initial (i.e., pre-jump) pH, and is dependent on initial pH in a manner similar to the pH dependence of Fe3+ adsorption to other oxides. We suggest that the excess Fe released in the transients is derived from partial dissolution or depolymerization of the iron (hydr)oxide at pH ~ I and the transition of such Fe into the adsorbed state on the mineral surface.
    [Show full text]
  • High-Temperature Thermomagnetic Properties of Vivianite Nodules
    EGU Journal Logos (RGB) Open Access Open Access Open Access Advances in Annales Nonlinear Processes Geosciences Geophysicae in Geophysics Open Access Open Access Natural Hazards Natural Hazards and Earth System and Earth System Sciences Sciences Discussions Open Access Open Access Atmospheric Atmospheric Chemistry Chemistry and Physics and Physics Discussions Open Access Open Access Atmospheric Atmospheric Measurement Measurement Techniques Techniques Discussions Open Access Open Access Biogeosciences Biogeosciences Discussions Open Access Open Access Clim. Past, 9, 433–446, 2013 Climate www.clim-past.net/9/433/2013/ Climate doi:10.5194/cp-9-433-2013 of the Past of the Past © Author(s) 2013. CC Attribution 3.0 License. Discussions Open Access Open Access Earth System Earth System Dynamics Dynamics Discussions High-temperature thermomagnetic properties of Open Access Open Access vivianite nodules, Lake El’gygytgyn, Northeast RussiaGeoscientific Geoscientific Instrumentation Instrumentation P. S. Minyuk1, T. V. Subbotnikova1, L. L. Brown2, and K. J. Murdock2 Methods and Methods and 1North-East Interdisciplinary Scientific Research Institute, Far East Branch of the Russian AcademyData Systems of Sciences, Data Systems Magadan, Russia Discussions Open Access 2 Open Access Department of Geosciences, University of Massachusetts, Amherst, USA Geoscientific Geoscientific Correspondence to: P. S. Minyuk ([email protected]) Model Development Model Development Received: 7 September 2012 – Published in Clim. Past Discuss.: 9 October 2012 Discussions Revised: 15 January 2013 – Accepted: 15 January 2013 – Published: 19 February 2013 Open Access Open Access Hydrology and Hydrology and Abstract. Vivianite, a hydrated iron phosphate, is abun- 1 Introduction Earth System Earth System dant in sediments of Lake El’gygytgyn, located in the Anadyr Mountains of central Chukotka, northeastern Rus- Sciences Sciences sia (67◦300 N, 172◦050 E).
    [Show full text]
  • Redox Trapping of Arsenic During Groundwater Discharge in Sediments from the Meghna Riverbank in Bangladesh
    Redox trapping of arsenic during groundwater discharge in sediments from the Meghna riverbank in Bangladesh S. Dattaa,b, B. Maillouxc, H.-B. Jungd, M. A. Hoquee, M. Stutea,c, K. M. Ahmede, and Y. Zhenga,d,1 aLamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, New York, NY 10964; bKansas State University, Department of Geology, Manhattan, KS 66506; cBarnard College, Department of Environmental Sciences, New York, NY 10027; dQueens College, School of Earth and Environmental Sciences, City University of New York, Flushing, New York, NY 11367; and eUniversity of Dhaka, Department of Geology, Dhaka, 1000 Bangladesh Communicated by Charles H. Langmuir, Harvard University, Cambridge, MA, July 30, 2009 (received for review September 5, 2007) Groundwater arsenic (As) is elevated in the shallow Holocene Results aquifers of Bangladesh. In the dry season, the shallow groundwa- Aquifers in the GBMD. The Ganges and Brahmaputra rivers coalesce ter discharges to major rivers. This process may influence the northwest of Dhaka and then join the Meghna River south of chemistry of the river and the hyporheic zone sediment. To assess Dhaka before flowing into the Bay of Bengal (see Fig. 1). Bang- the fate of As during discharge, surface (0–5 cm) and subsurface ladesh is less than 10 m above sea level, except for the uplifted (1–3 m) sediment samples were collected at 9 sites from the bank Pleistocene terraces, the Chittagong Hills, and the hilly area in the of the Meghna River along a transect from its northern source northeast. The sandy, unconsolidated Pleistocene to Holocene (25° N) to the Bay of Bengal (22.5° N).
    [Show full text]
  • Petrography and Geochemistry of the Banded Iron Formation of the Gangfelum Area, Northeastern Nigeria
    Earth Science Research; Vol. 7, No. 1; 2018 ISSN 1927-0542 E-ISSN 1927-0550 Published by Canadian Center of Science and Education Petrography and Geochemistry of the Banded Iron Formation of the Gangfelum Area, Northeastern Nigeria Anthony Temidayo Bolarinwa1 1 Department of Geology, University of Ibadan, Ibadan, Nigeria Correspondence: Anthony Temidayo Bolarinwa, Department of Geology, University of Ibadan, Ibadan, Nigeria. E-mail: [email protected] Received: September 15, 2016 Accepted: October 3, 2016 Online Published: October 3, 2017 doi:10.5539/esr.v7n1p25 URL: https://doi.org/10.5539/esr.v7n1p25 Abstract The Gangfelum Banded Iron Formation (BIF) is located within the basement complex of northeastern Nigeria. It is characterized by alternate bands of iron oxide and quartz. Petrographic studies show that the BIF consist mainly of hematite, goethite subordinate magnetite and accessory minerals including rutile, apatite, tourmaline and zircon. Chemical data from inductively coupled plasma optical emission spectrometer (ICP-OES) and inductively coupled plasma mass spectrometer (ICP-MS) show that average Fe2O3(t) is 53.91 wt.%. The average values of Al2O3 and CaO are 1.41 and 0.05 wt.% respectively, TiO2 and MnO are less than 0.5 wt. % each. The data suggested that the BIF is the oxide facies type. Trace element concentrations of Ba (67-332 ppm), Ni (28-35 ppm), Sr (13-55 ppm) and Zr (16-25 ppm) in the Gangfelum BIF are low and similar to the Maru and Muro BIF in northern Nigeria and also the Algoma iron formation from North America, the Orissa iron oxide facies of India and the Itabirite from Minas Gerais in Brazil.
    [Show full text]
  • Visible-To-Near-Infrared Spectral Variability of Hydrated Sulfates and Candidate Mars Landing Sites
    Western Washington University Western CEDAR WWU Graduate School Collection WWU Graduate and Undergraduate Scholarship Winter 2018 Visible-to-Near-Infrared Spectral Variability of Hydrated Sulfates and Candidate Mars Landing Sites: Implications for the Mastcam- Z Investigation on NASA’s Mars-2020 Rover Mission Darian Dixon Western Washington University, [email protected] Follow this and additional works at: https://cedar.wwu.edu/wwuet Part of the Geology Commons Recommended Citation Dixon, Darian, "Visible-to-Near-Infrared Spectral Variability of Hydrated Sulfates and Candidate Mars Landing Sites: Implications for the Mastcam-Z Investigation on NASA’s Mars-2020 Rover Mission" (2018). WWU Graduate School Collection. 638. https://cedar.wwu.edu/wwuet/638 This Masters Thesis is brought to you for free and open access by the WWU Graduate and Undergraduate Scholarship at Western CEDAR. It has been accepted for inclusion in WWU Graduate School Collection by an authorized administrator of Western CEDAR. For more information, please contact [email protected]. Visible-to-Near-Infrared Spectral Variability of Hydrated Sulfates and Candidate Mars Landing Sites: Implications for the Mastcam-Z Investigation on NASA’s Mars-2020 Rover Mission By Darian Dixon Accepted in Partial Completion of the Requirements for the Degree Master of Science Kathleen L. Kitto, Dean of the Graduate School ADVISORY COMMITTEE Chair, Dr. Melissa Rice Dr. Pete Stelling Dr. Michael Kraft MASTER’S THESIS In presenting this thesis in partial fulfillment of the requirements for a master’s degree at Western Washington University, I grant to Western Washington University the non-exclusive royalty-free right to archive, reproduce, distribute, and display the thesis in any and all forms, including electronic format, via any digital library mechanisms maintained by WWU.
    [Show full text]
  • The Transformation of Ferrihydrite Into Goethite Or Hematite, Revisited Yannick Cudennec, André Lecerf
    The transformation of ferrihydrite into goethite or hematite, revisited Yannick Cudennec, André Lecerf To cite this version: Yannick Cudennec, André Lecerf. The transformation of ferrihydrite into goethite or hematite, revisited. Journal of Solid State Chemistry, Elsevier, 2006, 179 (3), pp.716-722. 10.1016/j.jssc.2005.11.030. hal-02495178 HAL Id: hal-02495178 https://hal.archives-ouvertes.fr/hal-02495178 Submitted on 3 Apr 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Journal of Solid State Chemistry 179 (2AAO) 703-709 The transformation of ferrihydrite into goethite or hematite, revisited Yannick Cudennec_, Andre' Lecerf Groupe de Recherche en Chimie et Me'tallurgie, Institut National des Sciences Applique'es de Rennes, 20 avenue des buttes de Coe"smes,35043 Rennes cedex, France The transformation of ferrihydrite into goethite or hematite, revisited Yannick Cudennec , André Lecerf Groupe de Recherche en Chimie et Métallurgie, Institut National des Sciences Appliquées de Rennes, 20 avenue des buttes de Coësmes, 35043 Rennes cedex, France. Abstract During the oxidation of iron, poorly crystallized phases are firstly formed: 2 line-ferrihydrite and 6-line ferrihydrite, which present for the last phase, a similarity with wustite FeO but also with hematite o-FezO3.
    [Show full text]
  • Hematite and Goethite Inclusions in Low-Grade
    HEMATITE AND GOETHITE INCLUSIONS IN LOW-GRADE DOLOMITIC BANDED IRON FORMATIONS: PHYSICAL PARAMETER EVALUATION TO OPTIMIZE ORE BENEFICIATION Beate Orberger, Christiane Wagner, Alina Tudryn, Benoît Baptiste, Richard Wirth, Rachael Morgan, Serge Miska To cite this version: Beate Orberger, Christiane Wagner, Alina Tudryn, Benoît Baptiste, Richard Wirth, et al.. HEMATITE AND GOETHITE INCLUSIONS IN LOW-GRADE DOLOMITIC BANDED IRON FORMATIONS: PHYSICAL PARAMETER EVALUATION TO OPTIMIZE ORE BENEFICIA- TION. XXVIII International Mineral Processing Congress Proceedings , Canadian Institute of Mining, Metallurgy and Petroleum, 2016, pp.1-11. hal-01394125 HAL Id: hal-01394125 https://hal.archives-ouvertes.fr/hal-01394125 Submitted on 8 Nov 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. IMPC 2016: XXVIII International Mineral Processing Congress Proceedings - ISBN: 978-1-926872-29-2 HEMATITE AND GOETHITE INCLUSIONS IN LOW-GRADE DOLOMITIC BANDED IRON FORMATIONS: PHYSICAL PARAMETER EVALUATION TO OPTIMIZE ORE BENEFICIATION *B. Orberger1, C. Wagner2, A. Tudryn1,
    [Show full text]
  • Transformation of Goethite/Ferrihydrite to Hematite and Maghemite Under Temperate Humid Conditions in Denmark
    Geophysical Research Abstracts Vol. 14, EGU2012-3400, 2012 EGU General Assembly 2012 © Author(s) 2012 Transformation of goethite/ferrihydrite to hematite and maghemite under temperate humid conditions in Denmark P. Nørnberg (1), K. Finster (2), H.P. Gunnlaugsson (3), S.K. Jensen (4), J.P. Merrison (5), and A.L. Vendelboe (6) (1) Aarhus University, Department of Geosciences, Aarhus, Denmark ([email protected]), (2) Aarhus University, Department of Bioscience, Aarhus, Denmark, (3) Aarhus University, Department of Physics and Astronomy, Aarhus, Denmark, (4) Aarhus University, Department of Chemistry, Aarhus, Denmark, (5) Aarhus University, Department of Physics and Astronomy, Aarhus, Denmark, (6) Aarhus University, Department of Agroecology, Tjele, Denmark At a number of sandy soil sites in Mid Jutland, Denmark, with iron content of 1-2%, very red spots (Munsell colour: dusky red 10R 3/4) of a few square meters are found. These spots are most likely due to burning events. After the fire ashes raised pH. This dispersed silt and clay size soil particles which were then transported with seepage water down into lower soil horizons. These particles contain hematite and maghemite due to influence of the fire. However, a long-standing unresolved question is how hematite and maghemite can also be present along with goethite and ferrihydrite, in the same geographical region, and in extended areas with high iron content (8-40 %) in the topsoil. Hematite and particularly maghemite would normally not be expected to form under the temperate humid Danish climate, but be interpreted as the result of high temperature as found in tropical regions or as seen in soils exposed to fire.
    [Show full text]
  • Study of the Calcination Process of Two Limonitic Iron Ores Between 250 °C and 950 °C
    Lisbeth Longa-Avello - Cristina Pereyra-Zerpa - Julio Andrés Casal-Ramos - Pedro Delvasto Study of the calcination process of two limonitic iron ores between 250 °C and 950 °C Estudio del proceso de calcinación en dos minerales de hierro limoníticos entre 250 °C y 950 °C Estudo do processo de calcinação em dois minerais de ferro limoníticos entre 250 °C e 950 °C Lisbeth Longa-Avello* Cristina Pereyra-Zerpa** Fecha de recepción: 20 de septiembre de 2016 Julio Andrés Casal-Ramos*** Fecha de aprobación: 20 de marzo de 2017 Pedro Delvasto**** Abstract The dehydration process of two limonitic ores from Venezuela was studied between 250 °C and 950 °C by means of thermogravimetry, infrared spectroscopy, and x-ray diffraction. These techniques indicated for both minerals that the goethite-to-hematite transformation occurred in the range of 250-350 °C. In addition, the x-ray diffraction showed a structural re-arrangement within the orebody above 350 °C, temperature above which only the hematite structure is recognizable. Finally, infrared spectroscopy revealed that such transformation implies the loss of structural OH- functional groups, characteristic of the limonite. Keywords: Iron Ore; Limonite; Thermal Modification of Minerals. Resumen Se estudió el proceso de deshidratación de dos minerales limoníticos de Venezuela entre 250 °C y 950 °C, usando termogravimetría, espectroscopia infrarroja y difracción de rayos x. Para ambos materiales, estas técnicas indicaron que la transformación de goethita a hematita ocurrió en el rango de 250 °C a 350 °C. Adicionalmente, la difracción de rayos X mostró un rearreglo estructural dentro de la mena a una temperatura por encima de 350 °C; a temperaturas mayores, solo se reconoce la estructura de la hematita.
    [Show full text]
  • Composition of Mars, Michelle Wenz
    The Composition of Mars Michelle Wenz Curiosity Image NASA Importance of minerals . Role in transport and storage of volatiles . Ex. Water (adsorbed or structurally bound) . Control climatic behavior . Past conditions of mars . specific pressure and temperature formation conditions . Constrains formation and habitability Curiosity Rover at Mount Sharp drilling site, NASA image Missions to Mars . 44 missions to Mars (all not successful) . 21 NASA . 18 Russia . 1 ESA . 1 India . 1 Japan . 1 joint China/Russia . 1 joint ESA/Russia . First successful mission was Mariner 4 in 1964 Credit: Jason Davis / astrosaur.us, http://utprosim.com/?p=808 First Successful Mission: Mariner 4 . First image of Mars . Took 21 images . No evidence of canals . Not much can be said about composition Mariner 4, NASA image Mariner 4 first image of Mars, NASA image Viking Lander . First lander on Mars . Multispectral measurements Viking Planning, NASA image Viking Anniversary Image, NASA image Viking Lander . Measured dust particles . Believed to be global representation . Computer generated mixtures of minerals . quartz, feldspar, pyroxenes, hematite, ilmenite Toulmin III et al., 1977 Hubble Space Telescope . Better resolution than Mariner 6 and 7 . Viking limited to three bands between 450 and 590 nm . UV- near IR . Optimized for iron bearing minerals and silicates Hubble Space Telescope NASA/ESA Image featured in Astronomy Magazine Hubble Spectroscopy Results . 1994-1995 . Ferric oxide absorption band 860 nm . hematite . Pyroxene 953 nm absorption band . Looked for olivine contributions . 1042 nm band . No significant olivine contributions Hubble Space Telescope 1995, NASA Composition by Hubble . Measure of the strength of the absorption band . Ratio vs.
    [Show full text]
  • Silicon Increases the Phosphorus Availability of Arctic Soils
    www.nature.com/scientificreports OPEN Silicon increases the phosphorus availability of Arctic soils Jörg Schaller 1, Samuel Faucherre2, Hanna Joss1, Martin Obst3, Mathias Goeckede 4, Britta Planer-Friedrich1, Stefan Peifer5, Benjamin Gilfedder6 & Bo Elberling 2 Received: 6 September 2018 Phosphorus availability in soils is an important parameter infuencing primary production in terrestrial Accepted: 4 December 2018 ecosystems. Phosphorus limitation exists in many soils since a high proportion of soil phosphorus is Published: xx xx xxxx stored in unavailable forms for plants, such as bound to iron minerals or stabilized organic matter. This is in spite of soils having a high amount of total soil phosphorus. The feasibility of silicon to mobilize phosphorus from strong binding sites of iron minerals has been shown for marine sediments but is less well studied in soils. Here we tested the efect of silicon on phosphorus mobilization for 143 Artic soils (representing contrasting soil characteristics), which have not been afected by agriculture or other anthropogenic management practices. In agreement with marine studies, silicon availabilities were signifcantly positive correlated to phosphorus mobilization in these soils. Laboratory experiments confrmed that silicon addition signifcantly increases phosphorus mobilization, by mobilizing Fe(II)-P phases from mineral surfaces. Silicon addition increased also soil respiration in phosphorus defcient soils. We conclude that silicon is a key component regulating mobilization of phosphorous in Arctic soils, suggesting that this may also be important for sustainable management of phosphorus availability in soils in general. Phosphorus (P) is a key element for metabolic pathways and carbon (C) turnover on Earth. All organisms need P for their primary functioning.
    [Show full text]
  • 1 Review and New Data from Wadi Kareim 2
    1 Petrological and Geochemical Characteristics of Egyptian Banded Iron Formations: 2 Review and New Data from Wadi Kareim 3 4 K. I. Khalil1, and A. K. El-Shazly2* 5 6 1 Geology Department, Faculty of Science, University of Alexandria, Moharram Bey, Alexandria, 7 Egypt 8 2 Geology Department, Marshall University, 1 John Marshall Dr., Huntington, WV 25755 9 10 *Corresponding Author (e-mail: [email protected]). 11 12 # of words in text: 8307 13 # of words in references: 2144 14 15 Abbreviated title: Egyptian BIFs 16 17 Abstract 18 19 The banded iron formations in the eastern desert of Egypt are small, deformed, bodies 20 intercalated with metamorphosed Neoproterozoic volcaniclastic rocks. Although the 13 21 banded iron deposits have their own mineralogical, chemical, and textural characteristics, 22 they have many similarities, the most notable of which are the lack of sulfide and paucity of 23 carbonate facies minerals, a higher abundance of magnetite over hematite in the oxide 24 facies, and a well-developed banding/ lamination. Compared to Algoma, Superior, and 25 Rapitan type banded iron ores, the Egyptian deposits have very high Fe/Si ratios, high Al2O3 26 content, and HREE-enriched patterns. The absence of wave-generated structures in most of 27 the Egyptian deposits indicates sub-aqueous precipitation below wave base, whereas their 28 intercalation with poorly sorted volcaniclastic rocks with angular clasts suggests a 29 depositional environment proximal to epiclastic influx. The Egyptian deposits likely formed in 30 small fore-arc and back-arc basins through the precipitation of Fe silicate gels under slightly 31 euxinic conditions.
    [Show full text]