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 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 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 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 Vanadium Isotopes written by Sune G. Nielsen and published by Cambridge University Press. This book was released on 2021-01-31 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vanadium isotope ratios (51V/50V) have potential to provide information about changes in past ocean oxygen contents. In particular, V isotopes may find utility in tracing variations at non-zero oxygen concentrations because the redox couple that controls V elemental and isotopic abundances in seawater (vanadate-vanadyl) appears to operate around 10M O2. This characteristic sets V isotopes apart from many other metal isotope redox proxies that require more reducing conditions to register significant changes in their isotope budgets. The oxygen abundance sensitivity range of V isotopes suggests that this paleoproxy could be particularly useful in tracing marine oxygenation changes throughout the Phanerozoic and potentially beyond.
Download or read book Stable Isotope Geochemistry written by Jochen Hoefs and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable Isotope Geochemistry is an introduction to the use of stable isotopes in the fields of geoscience. It is subdivided into three parts: - theoretical and experimental principles; - fractionation mechanisms of light elements; - the natural variations of geologically important reservoirs. In this updated 4th edition many of the chapters have been expanded, especially those on techniques and environmental aspects. The main focus is on recent results and new developments. For students and scientists alike the book will be a primary reference with regard to how and where stable isotopes can be used to solve geological problems.
Download or read book Modern and Ancient Continental Shelf Anoxia written by Richard V. Tyson and published by Geological Society Publishing House. This book was released on 1991 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Micro XRF Studies of Sediment Cores written by Ian W. Croudace and published by Springer. This book was released on 2015-07-21 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents papers on the use of micro-XRF core scanners in palaeoenvironmental research. It contains a broad ranging view of instrument capability and points to future developments that will help contribute to higher precision elemental data and faster core analysis. Readers will find a diverse range of research by leading experts that have used micro-XRF core scanners in a wide range of scientific applications. The book includes specific application papers reporting on the use of XRF core scanners in a variety of marine, lacustrine, and pollution studies. In addition, coverage also examines practical aspects of core scanner usage, data optimisation and data calibration and interpretation. In a little over a decade, micro-XRF sediment core scanners have made a substantive contribution to palaeoenvironmental research. Their impact is based on their ability to rapidly, non-destructively and automatically scan sediment cores. Not only do they rapidly provide important proxy data without damaging samples, but they can obtain environmental data at decadal, annual and even sub-annual scales. This volume will help both experienced and new users of these non-destructive core scanners take full advantage of one of the most powerful geochemical screening tools in the environmental scientist's toolbox.
Download or read book Geochemistry of Sedimentary Carbonates written by J.W. Morse and published by Elsevier. This book was released on 1990-08-27 with total page 725 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the more basic aspects of carbonate minerals and their interaction with aqueous solutions; modern marine carbonate formation and sediments; carbonate diagenesis (early marine, meteoric and burial); the global cycle of carbon and human intervention; and the role of sedimentary carbonates as indicators of stability and changes in the Earth's surface environment. The selected subjects are presented with sufficient background information to enable the non-specialist to understand the basic chemistry involved. Tested on classes taught by the authors, and approved by the students, this comprehensive volume will prove itself to be a valuable reference source to students, researchers and professionals in the fields of oceanography, geochemistry, petrology, environmental science and petroleum geology.
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 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 Chemostratigraphy Across Major Chronological Boundaries written by Alcides N. Sial and published by John Wiley & Sons. This book was released on 2018-12-18 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Winner of the 2020 PROSE Award for Earth Science! Exploring environmental changes through Earth’s geological history using chemostratigraphy Chemostratigraphy is the study of the chemical characteristics of different rock layers. Decoding this geochemical record across chronostratigraphic boundaries can provide insights into geological history, past climates, and sedimentary processes. Chemostratigraphy Across Major Chronological Boundaries presents state-of-the-art applications of chemostratigraphic methods and demonstrates how chemical signatures can decipher past environmental conditions. Volume highlights include: Presents a global perspective on chronostratigraphic boundaries Describes how different proxies can reveal distinct elemental and isotopic events in the geologic past Examines the Archaean-Paleoproterozoic, Proterozoic-Paleozoic, Paleozoic-Mesozoic, and Mesozoic-Paleogene boundaries Explores cause-and-effect through major, trace, PGE, and REE elemental, stable, and radiogenic isotopes Offers solutions to persistent chemostratigraphic problems on a micro-global scale Geared toward academic and researchgeoscientists, particularly in the fields of sedimentary petrology, stratigraphy, isotope geology, geochemistry, petroleum geology, atmospheric science, oceanography, climate change and environmental science, Chemostratigraphy Across Major Chronological Boundaries offers invaluable insights into environmental evolution and climatic change. Read the Editors' Vox: https://eos.org/editors-vox/unravelling-the-past-using-elements-and-isotopes
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 Stable Isotope Geochemistry written by Jochen Hoefs and published by Springer. This book was released on 2015-07-09 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable Isotope Geochemistry is an introduction to the use of stable isotopes in the geosciences. For students and scientists alike the book will be a primary source of information with regard to how and where stable isotopes can be used to solve geological problems. 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. In the last decade, major advances in multicollector-ICP-mass-spectrometry enable the precise determination of a wide range of transition and heavy elements. Progress in analysing the rare isotopes of certain elements allows the distinction between mass-dependent and mass-independent fractionations. These major advances in analytical techniques make an extended new edition necessary. Special emphasis has been given to the growing field of “non-traditional” isotope systems. Many new references have been added, which will enable quick access to recent literature.
Download or read book Calculation of Equilibrium Constants for Isotopic Exchange Reactions written by Jacob Bigeleisen and published by . This book was released on 1947 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
