Download or read book Molybdenum as a Paleoredox Proxy written by Stephan R. Hlohowskyj and published by Cambridge University Press. This book was released on 2021-09-09 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molybdenum (Mo) is a widely used trace metal for investigating redox conditions. However, unanswered questions remain that concentration and bulk isotopic analysis cannot specially answer. Improvements can be made by combining new geochemical techniques to traditional methods of Mo analysis. In this Element, we propose a refinement of Mo geochemistry within aquatic systems, ancient rocks, and modern sediments through molecular geochemistry (systematically combining concentration, isotope ratio, elemental mapping, and speciation analyses). Specifically, to intermediate sulfide concentrations governing Mo behavior below the 'switch-point' and dominant sequestration pathways in low oxygen conditions. The aim of this work is to 1) aid and improve the breadth of Mo paleoproxy interpretations by considering Mo speciation and 2) address outstanding research gaps concerning Mo systematics (cycling, partitioning, sequestration, etc.). The Mo paleoproxy has potential to solve ever complex research questions. By using molecular geochemical recommendations, improved Mo paleoproxy interpretations and reconstruction can be achieved.
Download or read book The Iron Speciation Paleoredox Proxy written by Simon W. Poulton and published by Cambridge University Press. This book was released on 2021-03-04 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: In one form or another, iron speciation has had a long history as a paleoredox proxy. The technique has been refined considerably over the years, and the most recent scheme is unique in its potential to distinguish three major oceanic redox states - oxygenated, ferruginous and euxinic. This Element covers the theory behind the proxy, methods involved in applying the technique, and potential complications in interpreting Fe speciation data. A series of case studies are also provided, which highlight how more advanced consideration of the data, often in concert with other techniques, can provide unprecedented insight into the redox state of ancient oceans.
Download or read book Large Igneous Provinces written by Richard E. Ernst and published by Cambridge University Press. This book was released on 2014-09-25 with total page 667 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large igneous provinces (LIPs) are intraplate magmatic events, involving volumes of mainly mafic magma upwards of 100,000 km3, and often above 1 million km3. They are linked to continental break-up, global environmental catastrophes, regional uplift and a variety of ore deposit types. In this up-to-date, fascinating book, leading expert Richard E. Ernst explores all aspects of LIPs, beginning by introducing their definition and essential characteristics. Topics covered include continental and oceanic LIPs; their origins, structures, and geochemistry; geological and environmental effects; association with silicic, carbonatite and kimberlite magmatism; and analogues of LIPs in the Archean, and on other planets. The book concludes with an assessment of LIPs' influence on natural resources such as mineral deposits, petroleum and aquifers. This is a one-stop resource for researchers and graduate students in a wide range of disciplines, including tectonics, igneous petrology, geochemistry, geophysics, Earth history, and planetary geology, and for mining industry professionals.
Download or read book Non Traditional Stable Isotopes written by Fang-Zhen Teng and published by Walter de Gruyter GmbH & Co KG. This book was released on 2017-03-06 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) makes it possible to precisely measure non-traditional stable isotopes. This volume reviews the current status of non-traditional isotope geochemistry from analytical, theoretical, and experimental approaches to analysis of natural samples. In particular, important applications to cosmochemistry, high-temperature geochemistry, low-temperature geochemistry, and geobiology are discussed. This volume provides the most comprehensive review on non-traditional isotope geochemistry for students and researchers who are interested in both the theory and applications of non-traditional stable isotope geochemistry.
Download or read book Encyclopedia of Geochemistry written by William M. White and published by Springer. This book was released on 2018-07-24 with total page 1680 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Encyclopedia is a complete and authoritative reference work for this rapidly evolving field. Over 200 international scientists, each experts in their specialties, have written over 330 separate topics on different aspects of geochemistry including geochemical thermodynamics and kinetics, isotope and organic geochemistry, meteorites and cosmochemistry, the carbon cycle and climate, trace elements, geochemistry of high and low temperature processes, and ore deposition, to name just a few. The geochemical behavior of the elements is described as is the state of the art in analytical geochemistry. Each topic incorporates cross-referencing to related articles, and also has its own reference list to lead the reader to the essential articles within the published literature. The entries are arranged alphabetically, for easy access, and the subject and citation indices are comprehensive and extensive. Geochemistry applies chemical techniques and approaches to understanding the Earth and how it works. It touches upon almost every aspect of earth science, ranging from applied topics such as the search for energy and mineral resources, environmental pollution, and climate change to more basic questions such as the Earth’s origin and composition, the origin and evolution of life, rock weathering and metamorphism, and the pattern of ocean and mantle circulation. Geochemistry allows us to assign absolute ages to events in Earth’s history, to trace the flow of ocean water both now and in the past, trace sediments into subduction zones and arc volcanoes, and trace petroleum to its source rock and ultimately the environment in which it formed. The earliest of evidence of life is chemical and isotopic traces, not fossils, preserved in rocks. Geochemistry has allowed us to unravel the history of the ice ages and thereby deduce their cause. Geochemistry allows us to determine the swings in Earth’s surface temperatures during the ice ages, determine the temperatures and pressures at which rocks have been metamorphosed, and the rates at which ancient magma chambers cooled and crystallized. The field has grown rapidly more sophisticated, in both analytical techniques that can determine elemental concentrations or isotope ratios with exquisite precision and in computational modeling on scales ranging from atomic to planetary.
Download or read book Earth History of Oxygen and the iprOxy written by Zunli Lu and published by Cambridge University Press. This book was released on 2020-10-08 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: How oxygen levels in Earth's atmosphere and oceans evolved has always been a central question in Earth System Science. Researchers have developed numerous tracers to tackle this question, utilizing geochemical characteristics of different elements. Iodine incorporated in calcium carbonate (including biogenic) minerals, reported as I/Ca, is a proxy for dissolved oxygen in seawater. Here we review the rationale behind this proxy, its recent applications and some potential future research directions.
Download or read book Understanding the Monterey Formation and Similar Biosiliceous Units across Space and Time written by Ivano W. Aiello and published by Geological Society of America. This book was released on 2022-09-27 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geochemical Signals in Dynamic Sedimentary Systems Along Continental Margins written by Natascha Riedinger and published by Frontiers Media SA. This book was released on 2022-05-04 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molybdenum Cofactors and Their role in the Evolution of Metabolic Pathways written by Luana Presta and published by Springer. This book was released on 2015-05-07 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this brief, the authors explore and review the current knowledge regarding the role of molybdenum in the evolution of biological systems and their interaction with biogeochemical cycles. Special emphasis is placed on biological nitrogen fixation and the nitrogen element cycle. The origin and evolution of molybdenum cofactor biosynthetic pathways as well as the evolutionary significance of molybdenum containing enzymes appearance is analyzed. Original data regarding nitrogen fixation pathways and related enzymes molecular evolution processes is presented. The trace element molybdenum is essential for nearly all organisms and forms the catalytic center of a large variety of enzymes such as nitrogenase, nitrate reductases, sulphite oxidase and xanthine oxidoreductases.
Download or read book Isotope Geochemistry written by William M. White and published by John Wiley & Sons. This book was released on 2023-02-13 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: ISOTOPE GEOCHEMISTRY Provides a thorough and up-to-date overview of radiogenic and stable isotope geochemistry Now in its second edition, Isotope Geochemistry presents a comprehensive introduction to radiogenic and stable isotope geochemistry. The first five chapters cover fundamentals including the physics of nuclei, radioactive decay, nucleosynthesis, geochronology, and the theory of stable isotope fractionation. The next chapter focuses on the isotope geochemistry of meteorites and their constraints on the formation of the solar system and the Earth. The subsequent three chapters cover radiogenic and stable isotope geochemistry evolution of the Earth’s mantle and crust. Three more chapters are devoted to the Earth’s surface, the exogene, including the hydrologic system, the biosphere, and climate. A new chapter in this edition focuses on the use of isotopes in paleontology and archeology. The final chapter is devoted to the isotope geochemistry of the noble gases. Illustrated in full color throughout, Isotope Geochemistry is intended primarily as a textbook for advanced undergraduate and graduate students. It is also intended as a reference for earth science professionals, reflecting the impact that isotope geochemistry has on virtually every aspect of the earth sciences, from climate change and geomorphology to geodynamics.
Download or read book Emerging Patterns in Proterozoic Lipid Biomarker Records written by Gordon D. Love and published by Cambridge University Press. This book was released on 2021-03-25 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diverse and abundant lipid biomarker assemblages have been reported from a variety of Proterozoic marine environments from the careful analysis of well-preserved rocks and oils. These molecular biosignatures have provided unique insights into the communities and the environmental conditions which characterized the Proterozoic marine biosphere. We summarize some of the major temporal patterns evident in Proterozoic lipid biomarkers found to date, whilst emphasizing the scale of local heterogeneity found within Neoproterozoic oceans from region to region, and their relationship with the evolving ecological, climatic and ocean/atmospheric redox conditions. Short commentaries on a selection of papers published from the last 15 years of biomarker literature are given. The focus here is on key studies, highlighted for further reading, which have helped to better constrain the timing of the ecological expansion of eukaryotes in Proterozoic oceans or which have impacted on our knowledge of the biological sources of Proterozoic biomarkers.
Download or read book Sulfidic Sediments and Sedimentary Rocks written by David Rickard and published by Newnes. This book was released on 2012-12-31 with total page 813 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with sedimentary sulfides which are the most abundant authigenic minerals in sediments. Special emphasis is given to the biogeochemistry that plays such a central role in the formation of sedimentary sulfides. It will be of interest to scientists in a number of disciplines, including geology, microbiology, chemistry and environmental science. The sulfur system is important to environmental scientists considering the present and future effects of pollution and anoxia. The development of the sulfur system – particularly the characteristics of ocean anoxia over the last 200 Ma – is useful in predicting the future fate of the Earth surface system as well as in understanding the past. The biochemistry and microbiology of the sulfur system are key to understanding microbial ecology and the evolution of life. - First monograph on sedimentary sulfides, covering the ancient and modern sedimentary sulfide systems - Comprehensive, integrating chemistry, microbiology, geology and environmental science - All key references are included and discussed
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.
Download or read book Iron Formations as Palaeoenvironmental Archives written by Kaarel Mänd and published by Cambridge University Press. This book was released on 2022-01-20 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ancient iron formations - iron and silica-rich chemical sedimentary rocks that formed throughout the Precambrian eons - provide a significant part of the evidence for the modern scientific understanding of palaeoenvironmental conditions in Archaean (4.0–2.5 billion years ago) and Proterozoic (2.5–0.539 billion years ago) times. Despite controversies regarding their formation mechanisms, iron formations are a testament to the influence of the Precambrian biosphere on early ocean chemistry. As many iron formations are pure chemical sediments that reflect the composition of the waters from which they precipitated, they can also serve as nuanced geochemical archives for the study of ancient marine temperatures, redox states, and elemental cycling, if proper care is taken to understand their sedimentological context.
Download or read book The Uranium Isotope Paleoredox Proxy written by Kimberly V. Lau and published by Cambridge University Press. This book was released on 2019-08-29 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uranium isotopes (238U/235U) have emerged as a proxy to reconstruct the redox conditions of the Earth's oceans and atmosphere based upon the large isotopic fractionation between reduced U(IV) and oxidized U(VI). Variations in 238U/235U, particularly when recorded in carbonate sediments, can track global trends in marine oxygenation and de-oxygenation. It is unique from other proxies because reduction primarily occurs at the sediment-water interface, and this sensitivity makes U isotopes especially relevant for the habitability of benthic animals. This Element covers the background, methods, and case studies of this promising tool for understanding Earth's environmental transitions, as rapid development continues to refine the accuracy of interpretations of 238U/235U records.
Download or read book Coastal Upwelling Its Sediment Record written by Jörn Thiede and published by Springer. This book was released on 1983-07-31 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: NATO Advanced Research Institutes are designed to explore unre solved problems. By focusing complementary expertise from various disciplines onto one unifying theme, they approach old problems in new ways. In line with this goal of the NATO Science Committee, and with substantial support from the u.s. Office of Naval Research and the Seabed Assessment Program of the u.s. National Science Founda tion, such a Research Institute on the theme of Coastal Qpw llinq and Its Sediment Record was held September 1-4, 1981, in Vilamoura, Portuqal. The theme implies a modification of uniformitarian thinking in earth science. Expectations were directed not so much towards find ing the key to the past as towards explorinq the limits of interpret inq the past based on present upwelling oceanography. Coastal up wellinq and its imprint on sediments are particularly well-suited for such a scientific inquiry. The oceanic processes and conditions characteristic of upwelling are well understood and are a well packaqed representation of ocean science that are familiar to qeolo gists, just as the maqnitude of bioproduction and sedimentation in upwellinq reqimes --among other bioloqical and geoloqical processes- have made oceanographers realize that the bottom has a feedback role for their models.
Download or read book Geochemistry of Non Traditional Stable Isotopes written by Clark M. Johnson and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal for Volume 55 of Reviews in Mineralogy and Geochemistry was to bring together a summary of the isotope geochemistry of non-traditional stable isotope systems as is known through 2003 for those elements that have been studied in some detail, and which have a variety of geochemical properties. In addition, recognizing that many of these elements are of interest to workers who are outside the traditional stable isotope fields, we felt it was important to include discussions on the broad isotopic variations that occur in the solar system, theoretical approaches to calculating isotopic fractionations, and the variety of analytical methods that are in use. We hope, therefore, that this volume proves to be useful to not only the isotope specialist, but to others who are interested in the contributions that these non-traditional stable isotopes may make toward understanding geochemical and biological cycles. The review chapters in this volume were the basis for a two-day short course on nontraditional stable isotopes held prior (May 15-16, 2004) to the spring AGU/CGU Meeting in Montreal, Canada.
