Download or read book Mechanisms of Sulfur Isotope Fractionation During Thermochemical Sulfate Reduction by Amino Acids written by Andrew Chorney and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The understanding of the evolution of the earth's early atmosphere has largely been based on the behavior of the multiple isotopes of sulfur. However experiments designed to mimic fractionation in both an oxygen poor atmosphere through SO2 photolysis and a presumably oxygen rich atmosphere though thermochemical sulfate reduction (TSR) have thus far been unable to confirm a mechanism capable of creating the mass independent fractionation of sulfur (MIF-S) signatures observed in Archean age rocks. This has created much controversy in how the MIF-S record is used to determine Archean environments. However large amounts of geochemical evidence suggest at least appreciable amounts of oxygen in the atmosphere and ocean at different stages through the Archean. This has motivated us to further explore TSR as a source of MIF-S through a rigorous investigation of how chemical speciation, experimental conditions, time, and rate effect sulfur isotope fractionation. Our results show the importance of initial sulfur redox state and chemistry, temperature, and organic reductant type in creating characteristic mass dependent and independent fractionations. Including previous TSR results (Watanabe et. al., 2009 and Oduro et. al., 2011) we report increased [delta]34S and [delta]36S fractionation in TSR products to 15.50[per mille symbol] and 1.5[per mille symbol] respectively and increased [delta]33S range from -.22 to 2.30[per mille symbol] in H2S largely through the use of mixtures of glycine and alanine. In sulfate we observe [delta]34S fractionation between 0.00 and 7.85[per mille symbol] and [delta]33S fractionation between -.15[per mille symbol] and 0.0[per mille symbol]. By quantifying fractionation amongst different sulfur bearing products produced during experiments and collected at experiment conclusions in addition to characterizing the effects due to various experimental conditions we are also able describe a schematic framework for the isotope effects during various steps of TSR. Fractionation from the magnetic isotope effect (MIE), the vibrational energy discontinuity effect (VEDE), first described for heterogeneous reactions by Lasaga et. al, 2008, and normal stable isotope mass dependently driven kinetic isotope effects (KIE) are utilized in this schematic to describe the experimental results. The MIE and VEDE are responsible for the MIF-S signatures observed in organic polysulfides and H2S at high temperatures. Additionally the effects of these mechanisms are greatly influenced by amino acid type, specifically in experiments that use a mixture of glycine and alanine. The VEDE and KIE are responsible for [delta]34S fractionation with the overall effect of producing sulfide depleted in 34S at lower temperatures. The interplay of these mechanisms is responsible for [delta]33S and [delta]34S trends observed in sulfides and sulfate samples. Based on this proposed schematic for sulfur isotope fractionation during TSR major trends and features in the Archean [delta]33S vs. [delta]34S and [delta]36S vs. [delta]33S record can be interpreted. Our results confirm that MIF-S signatures observed in natural samples are a product of depositional environment and possibly reflect characteristics of reactions specific to sedimentary basin conditions and early earth's tectonic regime.
Download or read book Stable Isotope Geochemistry written by Jochen Hoefs and published by Springer Nature. This book was released on 2021-10-08 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This classic textbook is an introduction to the systematics and the use of stable isotopes in geosciences. It is subdivided into three parts: i) theoretical and experimental principles, ii) fractionation processes of light and heavy elements, iii) the natural variations of geologically important reservoirs. Since the publication of the previous edition improvements in multi-collector ICP mass-spectrometry have increased the ability to measure isotope ratios with very high precision for many elements of the periodic table. The amount of published data has increased tremendously in the last years; thus, conclusions based on a limited database are now better constrained. In this new edition, therefore, 47 elements with resolvable natural variations in isotope composition are discussed. This increase of elements, together with advances in the calculation of equilibrium isotope fractionation using ab initio methods, has led to an unbelievable rise of publications, making substantial major revisions and extensions of the last edition necessary. Many new references have been added, which enable quick access to recent literature.
Download or read book Chemical and Isotopic Kinetics of Sulfate Reduction by Organic Matter Under Hydrothermal Conditions written by Charles Kaiser and published by . This book was released on 1988 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Sulfate Concentration on Stable Isotope Fractionation During Sulfate Reduction by Natural Populations of Sulfate Reducing Bacteria written by Michael B. Gade and published by . This book was released on 2002 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Treatise on Geochemistry written by and published by Newnes. This book was released on 2013-10-19 with total page 14787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated new edition of the widely acclaimed Treatise on Geochemistry has increased its coverage beyond the wide range of geochemical subject areas in the first edition, with five new volumes which include: the history of the atmosphere, geochemistry of mineral deposits, archaeology and anthropology, organic geochemistry and analytical geochemistry. In addition, the original Volume 1 on "Meteorites, Comets, and Planets" was expanded into two separate volumes dealing with meteorites and planets, respectively. These additions increased the number of volumes in the Treatise from 9 to 15 with the index/appendices volume remaining as the last volume (Volume 16). Each of the original volumes was scrutinized by the appropriate volume editors, with respect to necessary revisions as well as additions and deletions. As a result, 27% were republished without major changes, 66% were revised and 126 new chapters were added. In a many-faceted field such as Geochemistry, explaining and understanding how one sub-field relates to another is key. Instructors will find the complete overviews with extensive cross-referencing useful additions to their course packs and students will benefit from the contextual organization of the subject matter Six new volumes added and 66% updated from 1st edition. The Editors of this work have taken every measure to include the many suggestions received from readers and ensure comprehensiveness of coverage and added value in this 2nd edition The esteemed Board of Volume Editors and Editors-in-Chief worked cohesively to ensure a uniform and consistent approach to the content, which is an amazing accomplishment for a 15-volume work (16 volumes including index volume)!
Download or read book Meetings Abstracts January August 2006 written by and published by . This book was released on 2006 with total page 1436 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fractionation of the Stable Isotopes of Sulfur by Microorganisms with Particular Reference to the Sulfate reducing Bacteria written by Galen Everts Jones and published by . This book was released on 1955 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deconstructing the Dissimilatory Sulfate Reduction Pathway written by Emma Bertran and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Dissimilatory sulfate reduction plays a significant role in shaping the sulfur isotope composition of sedimentary sulfides. These, in turn, record the evolution of Earth's surface redox state. The fractionation produced by this microbial metabolism is controlled by the flux of sulfur through the respiratory reaction network and the isotopic effect associated with each component reaction. Although the net isotope fractionations of this metabolism have been well studied, unraveling the isotopic influence of each component of its pathway is still a challenge. The sulfite to sulfide reduction step is a particularly complicated one. Its biochemistry is not fully understood and the associated isotope effect is inferred from fractionations associated with the entire metabolic pathway or from in-vitro experiments with cell-free extracts.
Download or read book A Revised Monod type Rate Law Predicting Variable Sulfur Isotope Fractionation Factors as a Function of Microbial Sulfate Reduction Rate written by Max Greene Giannetta and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploring the Contributions of Liquid phase Sulfur Chemistry to the Mass independent Sulfur Fractionation of the Archean Rock Record written by Sebastian Hermann Kopf and published by . This book was released on 2010 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Archean sulfur mass-independent fractionation (S-MIF) has been widely recognized as one of the strongest indicators for the rise of atmospheric oxygen in the Early Proterozoic. A decade after its discovery, the wide-ranging implications of Archean sulfur MIF have been discussed extensively and despite a number of recent studies on the gas-phase chemistry of sulfur, no definite overall picture has emerged to date as to the precise origin and preservation of the Archean mass-independent sulfur signal. The interpretation of the Archean sulfur MIF as a strong constraint for atmospheric oxygen levels, however, requires a dominant atmospheric source of sulfur MIF. This study was aimed at investigating the potential contribution of the poorly explored mass-independent effects from liquid-phase sulfur chemistry and focused on sulfur isotope fractionation during liquid-phase photolytic breakdown of phenacylphenylsulfone (PPS) as a model system for initial investigation. Results confirm that MIF in this system is caused by the magnetic 33S isotope and excludes other mechanisms such as nuclear volume effects or vibronic coupling that would produce concomitant MIF in the 32S-34_3-3S triad. This provides a starting point for discussing the implications of magnetic isotope effects as a mechanism for mass-independent isotope fractionation in the chemical evolution of the sulfur cycle and suggests that liquid-phase processes such as the photolysis of PPS cannot constitute the principal source of mass-independent sulfur fractionation in the Archean.
Download or read book Fractionation of the stable isotopes of sulfur by microorganisms with written by Galen Everts Jones and published by . This book was released on 1955 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petroleum Abstracts written by and published by . This book was released on 1993 with total page 1752 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rates and Mechanisms of Thermochemical Sulphate Reduction written by Martin M. Cross and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Sulfur Isotopes to Determine the Effectiveness of Sulfate reduction in the Remediatation of Acid Mine Drainage at Wills Creek Constructed Wetland written by Sophia C. Hsu and published by . This book was released on 1998 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sulfur Isotope Fractionation by Proteus Vulgaris and Salmonella Heidelberg During the Reduction of Thiosulfate written by and published by . This book was released on 1980 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sulfur Biogeochemistry written by Jan P. Amend and published by Geological Society of America. This book was released on 2004 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atmospheric Evolution on Inhabited and Lifeless Worlds written by David C. Catling and published by Cambridge University Press. This book was released on 2017-04-13 with total page 595 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and authoritative text on the formation and evolution of planetary atmospheres, for graduate-level students and researchers.
