The Pyrite Trace Element Paleo-Ocean Chemistry Proxy

The Pyrite Trace Element Paleo-Ocean Chemistry Proxy

Author: Daniel D. Gregory

Publisher: Cambridge University Press

Published: 2020-12-24

Total Pages: 44

ISBN-13: 110884751X

DOWNLOAD EBOOK

The use of the trace element content of sedimentary pyrite as a proxy for the trace element composition of past oceans has recently emerged. The pyrite proxy has several potential advantages over bulk sample analysis: preservation through metamorphism; little dilution during analysis (samples are ablated not dissolved, allowing for the less abundant elements commonly held in the sulfide fraction to be investigated as proxies); accurate measurement of several elements simultaneously; the ability to screen sediments for hydrothermal overprint; and the technique can give information regarding trace element availably at multiple stages of diagenesis. Because of these multiple strengths, the pyrite trace element proxy is a valuable potential addition to the paleo-ocean chemistry tool kit.


Book Synopsis The Pyrite Trace Element Paleo-Ocean Chemistry Proxy by : Daniel D. Gregory

Download or read book The Pyrite Trace Element Paleo-Ocean Chemistry Proxy written by Daniel D. Gregory and published by Cambridge University Press. This book was released on 2020-12-24 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of the trace element content of sedimentary pyrite as a proxy for the trace element composition of past oceans has recently emerged. The pyrite proxy has several potential advantages over bulk sample analysis: preservation through metamorphism; little dilution during analysis (samples are ablated not dissolved, allowing for the less abundant elements commonly held in the sulfide fraction to be investigated as proxies); accurate measurement of several elements simultaneously; the ability to screen sediments for hydrothermal overprint; and the technique can give information regarding trace element availably at multiple stages of diagenesis. Because of these multiple strengths, the pyrite trace element proxy is a valuable potential addition to the paleo-ocean chemistry tool kit.

Vanadium Isotopes

Vanadium Isotopes

Author: Sune G. Nielsen

Publisher: Cambridge University Press

Published: 2021-01-28

Total Pages: 39

ISBN-13: 110885270X

DOWNLOAD EBOOK

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.


Book Synopsis Vanadium Isotopes by : Sune G. Nielsen

Download or read book Vanadium Isotopes written by Sune G. Nielsen and published by Cambridge University Press. This book was released on 2021-01-28 with total page 39 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.

Reconstructing Precambrian pCO2 and pO2 Using Paleosols

Reconstructing Precambrian pCO2 and pO2 Using Paleosols

Author: Nathan D. Sheldon

Publisher: Cambridge University Press

Published: 2021-03-04

Total Pages: 38

ISBN-13: 1108876811

DOWNLOAD EBOOK

Paleosols formed in direct contact with the Earth's atmosphere, so they can record the composition of the atmosphere through weathering processes and products. Herein we critically review a variety of different approaches for reconstructing atmospheric O2 and CO2 over the past three billion years. Paleosols indicate relatively low CO2 over that time, requiring additional greenhouse forcing to overcome the 'faint young Sun' paradox in the Archean and Mesoproterozoic, as well as low O2 levels until the Neoproterozoic. Emerging techniques will revise the history of Earth's atmosphere further and may provide a window into atmospheric evolution on other planets.


Book Synopsis Reconstructing Precambrian pCO2 and pO2 Using Paleosols by : Nathan D. Sheldon

Download or read book Reconstructing Precambrian pCO2 and pO2 Using Paleosols written by Nathan D. Sheldon and published by Cambridge University Press. This book was released on 2021-03-04 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleosols formed in direct contact with the Earth's atmosphere, so they can record the composition of the atmosphere through weathering processes and products. Herein we critically review a variety of different approaches for reconstructing atmospheric O2 and CO2 over the past three billion years. Paleosols indicate relatively low CO2 over that time, requiring additional greenhouse forcing to overcome the 'faint young Sun' paradox in the Archean and Mesoproterozoic, as well as low O2 levels until the Neoproterozoic. Emerging techniques will revise the history of Earth's atmosphere further and may provide a window into atmospheric evolution on other planets.

Barium Isotopes

Barium Isotopes

Author: Tristan J. Horner

Publisher: Cambridge University Press

Published: 2021-04-22

Total Pages: 44

ISBN-13: 1108857515

DOWNLOAD EBOOK

In the modern marine environment, barium isotope (δ138Ba) variations are primarily driven by barite cycling—barite incorporates 'light' Ba isotopes from solution, rendering the residual Ba reservoir enriched in 'heavy' Ba isotopes by a complementary amount. Since the processes of barite precipitation and dissolution are vertically segregated and spatially heterogeneous, barite cycling drives systematic variations in the barium isotope composition of seawater and sediments. This Element examines these variations; evaluates their global, regional, local, and geological controls; and, explores how δ138Ba can be exploited to constrain the origin of enigmatic sedimentary sulfates and to study marine biogeochemistry over Earth's history.


Book Synopsis Barium Isotopes by : Tristan J. Horner

Download or read book Barium Isotopes written by Tristan J. Horner and published by Cambridge University Press. This book was released on 2021-04-22 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the modern marine environment, barium isotope (δ138Ba) variations are primarily driven by barite cycling—barite incorporates 'light' Ba isotopes from solution, rendering the residual Ba reservoir enriched in 'heavy' Ba isotopes by a complementary amount. Since the processes of barite precipitation and dissolution are vertically segregated and spatially heterogeneous, barite cycling drives systematic variations in the barium isotope composition of seawater and sediments. This Element examines these variations; evaluates their global, regional, local, and geological controls; and, explores how δ138Ba can be exploited to constrain the origin of enigmatic sedimentary sulfates and to study marine biogeochemistry over Earth's history.

Emerging Patterns in Proterozoic Lipid Biomarker Records

Emerging Patterns in Proterozoic Lipid Biomarker Records

Author: Gordon D. Love

Publisher: Cambridge University Press

Published: 2021-03-25

Total Pages: 82

ISBN-13: 1108847536

DOWNLOAD EBOOK

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.


Book Synopsis Emerging Patterns in Proterozoic Lipid Biomarker Records by : Gordon D. Love

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.

Cerium Anomalies and Paleoredox

Cerium Anomalies and Paleoredox

Author: Rosalie Tostevin

Publisher: Cambridge University Press

Published: 2021-02-25

Total Pages: 46

ISBN-13: 1108847579

DOWNLOAD EBOOK

Ce anomalies track changes in oxygen availability due to the anomalous redox-sensitivity of Ce compared with the other rare earth elements. The proxy systematics have been calibrated experimentally as well as in modern anoxic water bodies. Ce anomalies are unique because they track intermediate manganous conditions, rather than fully anoxic conditions. In addition, they are sensitive to local–regional redox conditions, and can be analysed in chemical sediments such as carbonate rocks. This makes them especially useful as a tool to track local oxygen distribution in shallow shelf environments, where biodiversity is highest. This review focusses on the systematics of the Ce anomaly proxy, the preservation and extraction of the signal in sedimentary rocks, and the potential applications of the proxy.


Book Synopsis Cerium Anomalies and Paleoredox by : Rosalie Tostevin

Download or read book Cerium Anomalies and Paleoredox written by Rosalie Tostevin and published by Cambridge University Press. This book was released on 2021-02-25 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce anomalies track changes in oxygen availability due to the anomalous redox-sensitivity of Ce compared with the other rare earth elements. The proxy systematics have been calibrated experimentally as well as in modern anoxic water bodies. Ce anomalies are unique because they track intermediate manganous conditions, rather than fully anoxic conditions. In addition, they are sensitive to local–regional redox conditions, and can be analysed in chemical sediments such as carbonate rocks. This makes them especially useful as a tool to track local oxygen distribution in shallow shelf environments, where biodiversity is highest. This review focusses on the systematics of the Ce anomaly proxy, the preservation and extraction of the signal in sedimentary rocks, and the potential applications of the proxy.

Pelagic Barite

Pelagic Barite

Author: Weiqi Yao

Publisher: Cambridge University Press

Published: 2021-01-28

Total Pages: 46

ISBN-13: 1108847552

DOWNLOAD EBOOK

Reconstruction of ocean paleoproductivity and paleochemistry is paramount to understanding global biogeochemical cycles such as the carbon, oxygen and sulfur cycles and the responses of these cycles to changes in climate and tectonics. Paleo-reconstruction involves the application of various tracers that record seawater compositions, which in turn may be used to infer oceanic processes. Several important tracers are incorporated into pelagic barite, an authigenic mineral that forms in the water column. Here we summarize the utility of pelagic barite for the reconstruction of export production and as a recorder of seawater S, O, Sr, Ca and Ba.


Book Synopsis Pelagic Barite by : Weiqi Yao

Download or read book Pelagic Barite written by Weiqi Yao and published by Cambridge University Press. This book was released on 2021-01-28 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reconstruction of ocean paleoproductivity and paleochemistry is paramount to understanding global biogeochemical cycles such as the carbon, oxygen and sulfur cycles and the responses of these cycles to changes in climate and tectonics. Paleo-reconstruction involves the application of various tracers that record seawater compositions, which in turn may be used to infer oceanic processes. Several important tracers are incorporated into pelagic barite, an authigenic mineral that forms in the water column. Here we summarize the utility of pelagic barite for the reconstruction of export production and as a recorder of seawater S, O, Sr, Ca and Ba.

Calcium Isotopes

Calcium Isotopes

Author: Elizabeth M. Griffith

Publisher: Cambridge University Press

Published: 2021-01-21

Total Pages: 56

ISBN-13: 1108847595

DOWNLOAD EBOOK

Precise measurements of the calcium (Ca) isotopes have provided constraints on Ca cycling at global and local scales, and quantified rates of carbonate diagenesis in marine sedimentary systems. Key to applying Ca isotopes as a geochemical tracer of Ca cycling, carbonate (bio)mineralization, and diagenesis is an understanding of the impact of multiple factors potentially impacting Ca isotopes in the rock record. These factors include variations in stable isotopic fractionation factors, the influence of local-scale Ca cycling on Ca isotopic gradients in carbonate settings, carbonate dissolution and reprecipitation, and the relationship between the Ca isotopic composition of seawater and mineral phases that record the secular evolution of seawater chemistry.


Book Synopsis Calcium Isotopes by : Elizabeth M. Griffith

Download or read book Calcium Isotopes written by Elizabeth M. Griffith and published by Cambridge University Press. This book was released on 2021-01-21 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precise measurements of the calcium (Ca) isotopes have provided constraints on Ca cycling at global and local scales, and quantified rates of carbonate diagenesis in marine sedimentary systems. Key to applying Ca isotopes as a geochemical tracer of Ca cycling, carbonate (bio)mineralization, and diagenesis is an understanding of the impact of multiple factors potentially impacting Ca isotopes in the rock record. These factors include variations in stable isotopic fractionation factors, the influence of local-scale Ca cycling on Ca isotopic gradients in carbonate settings, carbonate dissolution and reprecipitation, and the relationship between the Ca isotopic composition of seawater and mineral phases that record the secular evolution of seawater chemistry.

Molybdenum as a Paleoredox Proxy

Molybdenum as a Paleoredox Proxy

Author: Stephan R. Hlohowskyj

Publisher: Cambridge University Press

Published: 2021-09-09

Total Pages: 57

ISBN-13: 1009002260

DOWNLOAD EBOOK

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.


Book Synopsis Molybdenum as a Paleoredox Proxy by : Stephan R. Hlohowskyj

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.

Encyclopedia of Geology

Encyclopedia of Geology

Author:

Publisher: Academic Press

Published: 2020-12-16

Total Pages: 5634

ISBN-13: 0081029098

DOWNLOAD EBOOK

Encyclopedia of Geology, Second Edition presents in six volumes state-of-the-art reviews on the various aspects of geologic research, all of which have moved on considerably since the writing of the first edition. New areas of discussion include extinctions, origins of life, plate tectonics and its influence on faunal provinces, new types of mineral and hydrocarbon deposits, new methods of dating rocks, and geological processes. Users will find this to be a fundamental resource for teachers and students of geology, as well as researchers and non-geology professionals seeking up-to-date reviews of geologic research. Provides a comprehensive and accessible one-stop shop for information on the subject of geology, explaining methodologies and technical jargon used in the field Highlights connections between geology and other physical and biological sciences, tackling research problems that span multiple fields Fills a critical gap of information in a field that has seen significant progress in past years Presents an ideal reference for a wide range of scientists in earth and environmental areas of study


Book Synopsis Encyclopedia of Geology by :

Download or read book Encyclopedia of Geology written by and published by Academic Press. This book was released on 2020-12-16 with total page 5634 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Geology, Second Edition presents in six volumes state-of-the-art reviews on the various aspects of geologic research, all of which have moved on considerably since the writing of the first edition. New areas of discussion include extinctions, origins of life, plate tectonics and its influence on faunal provinces, new types of mineral and hydrocarbon deposits, new methods of dating rocks, and geological processes. Users will find this to be a fundamental resource for teachers and students of geology, as well as researchers and non-geology professionals seeking up-to-date reviews of geologic research. Provides a comprehensive and accessible one-stop shop for information on the subject of geology, explaining methodologies and technical jargon used in the field Highlights connections between geology and other physical and biological sciences, tackling research problems that span multiple fields Fills a critical gap of information in a field that has seen significant progress in past years Presents an ideal reference for a wide range of scientists in earth and environmental areas of study