Paleoredox and pyritization of soft-bodied fossils in the Ordovician Frankfort Shale of New York

Multiple beds in the Frankfort Shale (Upper Ordovician, New York State), including the original “Beecher's Trilobite Bed,” yield fossils with pyritized soft-tissues. A bed-by-bed geochemical and sedimentological analysis was carried out to test previous models of soft-tissue pyritization by investigating environmental, depositional and diagenetic conditions in beds with and without soft-tissue preservation. Highly-reactive iron (FeHR), total iron (FeT), δ34S, organic carbon and redox-sensitive trace elements were measured. In particular, the partitioning of highly-reactive iron between iron-carbonates (Fe-carb), iron-oxides (Fe-ox), magnetite (Fe-mag), and pyrite (FeP) was examined. Overall, the multi-proxy sedimentary geochemical data suggest that the succession containing pyritized trilobite beds was deposited under a dysoxic water-column, in agreement with the paleontological data. The data do not exclude brief episodes of water-column anoxia characterized by a ferruginous rather than an euxinic state. However, the highest FeHR/FeT values and redox-sensitive trace element enrichments occur in siltstone portions of turbidite beds and in concretions, suggesting that subsequent diagenesis had a significant effect on the distribution of redox-sensitive elements in this succession. Moderately high FeHR/FeT and FeP/FeHR, low organic carbon, enriched δ34S, and the frequent presence of iron-rich carbonate concretions in beds with soft tissue preservation confirm that pyritization was favored where pore-waters were iron-dominated in sediments relatively poor in organic carbon.

[1]  Guangping Xu,et al.  Digestion methods for trace element measurements in shales: Paleoredox proxies examined , 2012 .

[2]  A. Knoll,et al.  Late Ediacaran redox stability and metazoan evolution , 2012 .

[3]  D. Canfield,et al.  Mechanism for Burgess Shale-type preservation , 2012, Proceedings of the National Academy of Sciences.

[4]  D. Briggs,et al.  PALEOECOLOGY OF THE OLENID TRILOBITE TRIARTHRUS: NEW EVIDENCE FROM BEECHER'S TRILOBITE BED AND OTHER SITES OF PYRITIZATION , 2011 .

[5]  T. Lyons,et al.  Joining forces: Combined biological and geochemical proxies reveal a complex but refined high-resolution palaeo-oxygen history in Devonian epeiric seas , 2011 .

[6]  A. Knoll,et al.  Geochemical evidence for widespread euxinia in the Later Cambrian ocean , 2011, Nature.

[7]  R. Aller,et al.  Unsteady diagenetic processes and sulfur biogeochemistry in tropical deltaic muds: Implications for oceanic isotope cycles and the sedimentary record , 2010 .

[8]  A. Knoll,et al.  An emerging picture of Neoproterozoic ocean chemistry: Insights from the Chuar Group, Grand Canyon, USA , 2010 .

[9]  J. Hagadorn,et al.  Beyond Beecher's Trilobite Bed: Widespread pyritization of soft tissues in the Late Ordovician Taconic foreland basin , 2009 .

[10]  D. Canfield,et al.  Animal evolution, bioturbation, and the sulfate concentration of the oceans , 2009, Proceedings of the National Academy of Sciences.

[11]  M. Droser,et al.  Palaeoecological patterns within the dysaerobic biofacies: Examples from Devonian black shales of New York state , 2009 .

[12]  A. Anbar,et al.  Tracking Euxinia in the Ancient Ocean: A Multiproxy Perspective and Proterozoic Case Study , 2009 .

[13]  R. Bustin,et al.  Investigating the use of sedimentary geochemical proxies for paleoenvironment interpretation of thermally mature organic-rich strata: Examples from the Devonian–Mississippian shales, Western Canadian Sedimentary Basin , 2009 .

[14]  J. L. Cisne.  BEECHER'S TRILOBITE BED REVISITED: ECOLOGY OF AN ORDOVICIAN DEEPWATER FAUNA , 2009 .

[15]  Carlton E. Bretta,et al.  DEPOSITIONAL DYNAMICS RECORDED IN MIXED SILICICLASTIC–CARBONATE MARINE SUCCESSIONS: INSIGHTS FROM THE UPPER ORDOVICIAN KOPE FORMATION OF OHIO AND KENTUCKY, U.S.A , 2009 .

[16]  J. B. Maynard,et al.  Trace-metal covariation as a guide to water-mass conditions in ancient anoxic marine environments , 2008 .

[17]  A. Knoll,et al.  Ferruginous Conditions Dominated Later Neoproterozoic Deep-Water Chemistry , 2008, Science.

[18]  B. Beckmann,et al.  Redox sensitivity of P cycling during marine black shale formation: Dynamics of sulfidic and anoxic, non-sulfidic bottom waters , 2008 .

[19]  R. Raiswell,et al.  Turbidite depositional influences on the diagenesis of Beecher's Trilobite Bed and the Hunsrück Slate; sites of soft tissue pyritization , 2008, American Journal of Science.

[20]  T. Lyons,et al.  Parallel, high-resolution carbon and sulfur isotope records of the evolving Paleozoic marine sulfur reservoir , 2007 .

[21]  D. Canfield,et al.  Late-Neoproterozoic Deep-Ocean Oxygenation and the Rise of Animal Life , 2007, Science.

[22]  A. Kampschultea,et al.  The sulfur isotopic evolution of Phanerozoic seawater based on the analysis of structurally substituted sulfate in carbonates , 2007 .

[23]  T. Lyons,et al.  A critical look at iron paleoredox proxies: New insights from modern euxinic marine basins , 2006 .

[24]  H. Brumsack,et al.  Anoxic vs dysoxic events reflected in sediment geochemistry during the Cenomanian-Turonian Boundary Event (Cretaceous) in the Umbria-Marche Basin of central Italy , 2006 .

[25]  Z. Berner,et al.  Palaeoenvironmental changes at the Frasnian/Famennian boundary in key European sections: Chemostratigraphic constraints , 2006 .

[26]  T. Lyons,et al.  Trace metals as paleoredox and paleoproductivity proxies: An update , 2006 .

[27]  Thomas J. Algeo,et al.  Mo–total organic carbon covariation in modern anoxic marine environments: Implications for analysis of paleoredox and paleohydrographic conditions , 2006 .

[28]  T. Bickert.  Influence of geochemical processes on stable isotope distribution in marine sediments , 2006 .

[29]  D. Canfield,et al.  Development of a sequential extraction procedure for iron: implications for iron partitioning in continentally derived particulates , 2005 .

[30]  T. Lyons,et al.  Trace metal records of regional paleoenvironmental variability in Pennsylvanian (Upper Carboniferous) black shales , 2004 .

[31]  J. Hower,et al.  High-resolution geochemistry and sequence stratigraphy of the Hushpuckney Shale (Swope Formation, eastern Kansas): implications for climato-environmental dynamics of the Late Pennsylvanian Midcontinent Seaway , 2004 .

[32]  J. B. Maynard,et al.  Trace-element behavior and redox facies in core shales of Upper Pennsylvanian Kansas-type cyclothems , 2004 .

[33]  T. Anderson,et al.  SOURCES AND MECHANISMS FOR THE ENRICHMENT OF HIGHLY REACTIVE IRON IN EUXINIC BLACK SEA SEDIMENTS , 2004 .

[34]  T. Lyons,et al.  Geochemistry of Fine-grained Sediments and Sedimentary Rocks , 2003 .

[35]  M. Droser,et al.  Paleoecology of the familiar trilobite Elrathia kingii: An early exaerobic zone inhabitant , 2003 .

[36]  T. Lyons,et al.  Contrasting sulfur geochemistry and Fe/Al and Mo/Al ratios across the last oxic-to-anoxic transition in the Cariaco Basin, Venezuela , 2003 .

[37]  L. Levin.  Oxygen minimum zone Benthos: Adaptation and community response to hypoxia , 2003 .

[38]  R. Raiswell,et al.  The low-temperature geochemical cycle of iron: From continental fluxes to marine sediment deposition , 2002 .

[39]  T. Lyons,et al.  An integrated assessment of a “type euxinic” deposit: Evidence for multiple controls on black shale deposition in the middle Devonian Oatka Creek formation , 2002 .

[40]  N. Savage,et al.  The Frasnian-Famennian events in a deep-shelf succession, Subpolar Urals: biotic, depositional, and geochemical records , 2002 .

[41]  D. Canfield,et al.  Isotope fractionation by sulfate-reducing natural populations and the isotopic composition of sulfide in marine sediments , 2001 .

[42]  R. Raiswell,et al.  An Indicator of Water-Column Anoxia: Resolution of Biofacies Variations in the Kimmeridge Clay (Upper Jurassic, U.K.) , 2001 .

[43]  J. Warren.  Dolomite: occurrence, evolution and economically important associations , 2000 .

[44]  R. Fortey.  Olenid trilobites: the oldest known chemoautotrophic symbionts? , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[45]  L. Levin,et al.  Macrobenthic community structure within and beneath the oxygen minimum zone, NW Arabian Sea , 2000 .

[46]  P. Hooper,et al.  XRF Analysis of Rocks and Minerals for Major and Trace Elements on a Single Low Dilution Li-tetraborate Fused Bead , 1999 .

[47]  S. Kasten,et al.  Simultaneous formation of iron-rich layers at different redox boundaries in sediments of the Amazon Deep-Sea Fan , 1998 .

[48]  D. Canfield,et al.  Sources of iron for pyrite formation in marine sediments , 1998 .

[49]  D. Canfield,et al.  Sulfur isotope fractionation during bacterial sulfate reduction in organic-rich sediments. , 1997, Geochimica et cosmochimica acta.

[50]  D. Z. Piper,et al.  Inorganic geochemical indicators of glacial-interglacial changes in productivity and anoxia on the California continental margin , 1997 .

[51]  M. Coleman,et al.  The Role of Iron in Mudstone Diagenesis: Comparison of Kimmeridge Clay Formation Mudstones from Onshore and Offshore (UKCS) Localities , 1997 .

[52]  S. Calvert,et al.  Rhenium and molybdenum enrichments in sediments as indicators of oxic, suboxic and sulfidic conditions of deposition , 1996 .

[53]  R. Raiswell,et al.  Controls on the pyritization of exceptionally preserved fossils; an analysis of the Lower Devonian Hunsrueck Slate of Germany , 1996 .

[54]  S. Calvert,et al.  Sedimentary geochemistry of manganese; implications for the environment of formation of manganiferous black shales , 1996 .

[55]  C. Curtis.  Post-depositional evolution of mudstones l: early days and parental influences , 1995, Journal of the Geological Society.

[56]  C. Brett,et al.  Distal sedimentation in a peripheral foreland basin; Ordovician black shales and associated flysch of the western Taconic Foreland, New York State and Ontario , 1995 .

[57]  D. Canfield,et al.  The production of 34S-depleted sulfide during bacterial disproportionation of elemental sulfur. , 1994, Science.

[58]  D. Canfield,et al.  A comparison of iron extraction methods for the determination of degree of pyritisation and the recognition of iron-limited pyrite formation. , 1994, Chemical geology.

[59]  C. Rice,et al.  The analysis of forms of sulfur in ancient sediments and sedimentary rocks: comments and cautions , 1993 .

[60]  S. Calvert,et al.  Geochemistry of Recent oxic and anoxic marine sediments: Implications for the geological record , 1993 .

[61]  P. Wignall.  Distinguishing between oxygen and substrate control in fossil benthic assemblages , 1993, Journal of the Geological Society.

[62]  C. Mitchell,et al.  The Geochemistry of the Utica Shale (Ordovician) of New York State and Quebec , 1993 .

[63]  D. Canfield,et al.  The reactivity of sedimentary iron minerals toward sulfide , 1992 .

[64]  H. Edenborn,et al.  Influence of an organic-poor landslide deposit on the early diagenesis of iron and manganese in a coastal marine sediment , 1992 .

[65]  H. Krouse,et al.  Sulfide Diagenesis and Sedimentation in the Albian Harmon Member, Western Canada , 1992 .

[66]  R. Raiswell,et al.  Pyritization of soft-bodied fossils: Beecher's Trilobite Bed, Upper Ordovician, New York State , 1991 .

[67]  R. Tyson,et al.  Modern and ancient continental shelf anoxia: an overview , 1991, Geological Society, London, Special Publications.

[68]  D. Bottjer,et al.  Oxygen-related biofacies in marine strata: an overview and update , 1991, Geological Society, London, Special Publications.

[69]  M. Wilkinson.  Evidence for surface reaction‐controlled growth of carbonate concretions in shales , 1989 .

[70]  D. Canfield.  Reactive iron in marine sediments. , 1989, Geochimica et cosmochimica acta.

[71]  B. Hay,et al.  Deposition in the Oxygen-Deficient Taconic Foreland Basin, Late Ordovician: Chapter 8 , 1988 .

[72]  J. Almond,et al.  Appendages and Habits of the Upper Ordovician Trilobite Triarthrus eatoni , 1987 .

[73]  R. Berner,et al.  Pyrite and organic matter in Phanerozoic normal marine shales , 1986 .

[74]  D. Hydes,et al.  Oxidation Fronts in Pelagic Sediments: Diagenetic Formation of Metal-Rich Layers , 1986, Science.

[75]  D. Canfield,et al.  The use of chromium reduction in the analysis of reduced inorganic sulfur in sediments and shales , 1986 .

[76]  M. Coleman,et al.  Geochemistry of diagenetic non-silicate minerals: kinetic considerations , 1985, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[77]  H. T. Mullins,et al.  Alternative biofacies model for dysaerobic communities , 1985 .

[78]  Robert Raiswell,et al.  Burial of organic carbon and pyrite sulfur in sediments over phanerozoic time: a new theory , 1983 .

[79]  D. Karig,et al.  Topography and tectonics of the Taconic outer trench slope as revealed through gradient analysis of fossil assemblages , 1982 .

[80]  M. Goldhaber,et al.  Mechanisms of sulfur incorporation and isotope fractionation during early diagenesis in sediments of the gulf of California , 1980 .

[81]  B. Jørgensen.  A theoretical model of the stable sulfur isotope distribution in marine sediments , 1979 .

[82]  M. I. Gusdal,et al.  The Production of , 1979 .

[83]  N. N. Zhabina,et al.  A method of determination of various sulfur compounds in sea sediments and rocks , 1978 .

[84]  K. H. Wedepohl.  Environmental influences on the chemical composition of shales and clays , 1971 .

[85]  R. Berner.  Migration of iron and sulfur within anaerobic sediments during early diagenesis , 1969 .

[86]  K. Turekian,et al.  Distribution of the Elements in Some Major Units of the Earth's Crust , 1961 .