Hydrogen and Oxygen Isotope Fractionation in Hydrous Minerals as Indicators of Fluid Source in Modern and Fossil Metasomatic Environments PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Hydrogen and Oxygen Isotope Fractionation in Hydrous Minerals as Indicators of Fluid Source in Modern and Fossil Metasomatic Environments PDF full book. Access full book title Hydrogen and Oxygen Isotope Fractionation in Hydrous Minerals as Indicators of Fluid Source in Modern and Fossil Metasomatic Environments by Emily Catherine Pope. Download full books in PDF and EPUB format.
Author: Emily Catherine Pope
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 243
Get Book Here
Book Description
Oxygen and hydrogen isotope properties of hydrous silicate minerals formed by weathering, hydrothermal, metamorphic and igneous processes provide a record of fluid-rock interaction. We utilize this isotopic record to 1) determine the source of geothermal fluids in two active geothermal systems in Iceland, and to evaluate the consequences of fluid-rock interaction on host rock, fluid and magma chemistry, and 2) to better characterize Earth's surface environments during the early Archaean. Geothermal systems within the active volcanic zone of Iceland provide a unique natural laboratory for studying fluid-rock interaction in magma-hydrothermal systems where the Mid-Atlantic ridge emerges onto land. The fluids of the Reykjanes geothermal system in southwest Iceland are derived from hydrothermally modified seawater. The anomalously low hydrogen isotope composition of these fluids is not due to mixing with local meteoric fluids, as previously supposed, but to diffusional exchange with relict hydrous alteration minerals, such as epidote, which retain an isotopic signature of glacially derived Ice Age fluids that existed early in the evolution of the geothermal system. In contrast, the meteoric-water dominated Krafla geothermal system, in northeast Iceland, displays wide isotopic heterogeneities in modern geothermal fluids and hydrothermal epidote that reflects a complex fluid evolution involving boiling, condensation and contamination by magmatic volatiles. A silicic melt that intruded the Iceland Deep Drilling Project drillhole IDDP-1 within the Krafla geothermal system appears to be largely derived from partial melting of hydrothermal alteration minerals, given the almost identical hydrogen isotope composition of glass sampled from drill cuttings and hydrothermal epidote. The oxygen isotope values of the rhyolite glass show the characteristically low-[lowercase Delta]18O values typical of Icelandic lavas, and result from mixing of a dominant mantle-derived basalt source and a lesser contribution of lighter oxygen from the incongruent melting of hydrothermally altered basalts within the Krafla caldera. The oxygen and hydrogen isotope characteristics of metamorphic fluids recorded in alteration minerals have applications to fossil metasomatic systems as well as modern ones. Serpentinites from the [greater than or equal to] 3.8 Ga Isua Supracrustal Belt (ISB) of West Greenland locally preserve isotope characteristics of their original formation by seawater alteration of ocean crust and suggest that the early Archaean oceans had oxygen isotopes comparable to modern day seawater, but a hydrogen isotope composition that is lower than modern seawater by 25 ± 5%. The hydrogen isotopes of Archaean oceans places mass balance constraints on the extent of hydrogen escape before the rise of atmospheric oxygen ~2.5 Ga, and by extension the maximum atmospheric methane levels during the early Archaean. The oxygen isotope composition predicted by these serpentinites suggests that the ocean was isotopically buffered by hydrothermal interaction with ocean crust by 3.8 Ga. Finally, chromian muscovite-quartz-carbonate veins in the ISB have oxygen and hydrogen stable isotope, elemental and mineralogical characteristics that are genetically similar to orogenic gold deposits in the fore-arc regions of Phanerozoic accretionary margins. We show that in both modern orogens and in the supracrustal sequence at Isua, these veins are the result of seawater-derived fluids liberated from subducting lithosphere interacting with ultramafic rocks in the mantle wedge and lower crust, before migrating up crustal-scale vertical fracture zones. The presence of these veins in the ISB and other Archaean-age deposits indicates that plate tectonic processes comparable to modern-day subduction existed as early as 3.8 Ga.
Author: Emily Catherine Pope
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 243
Get Book Here
Book Description
Oxygen and hydrogen isotope properties of hydrous silicate minerals formed by weathering, hydrothermal, metamorphic and igneous processes provide a record of fluid-rock interaction. We utilize this isotopic record to 1) determine the source of geothermal fluids in two active geothermal systems in Iceland, and to evaluate the consequences of fluid-rock interaction on host rock, fluid and magma chemistry, and 2) to better characterize Earth's surface environments during the early Archaean. Geothermal systems within the active volcanic zone of Iceland provide a unique natural laboratory for studying fluid-rock interaction in magma-hydrothermal systems where the Mid-Atlantic ridge emerges onto land. The fluids of the Reykjanes geothermal system in southwest Iceland are derived from hydrothermally modified seawater. The anomalously low hydrogen isotope composition of these fluids is not due to mixing with local meteoric fluids, as previously supposed, but to diffusional exchange with relict hydrous alteration minerals, such as epidote, which retain an isotopic signature of glacially derived Ice Age fluids that existed early in the evolution of the geothermal system. In contrast, the meteoric-water dominated Krafla geothermal system, in northeast Iceland, displays wide isotopic heterogeneities in modern geothermal fluids and hydrothermal epidote that reflects a complex fluid evolution involving boiling, condensation and contamination by magmatic volatiles. A silicic melt that intruded the Iceland Deep Drilling Project drillhole IDDP-1 within the Krafla geothermal system appears to be largely derived from partial melting of hydrothermal alteration minerals, given the almost identical hydrogen isotope composition of glass sampled from drill cuttings and hydrothermal epidote. The oxygen isotope values of the rhyolite glass show the characteristically low-[lowercase Delta]18O values typical of Icelandic lavas, and result from mixing of a dominant mantle-derived basalt source and a lesser contribution of lighter oxygen from the incongruent melting of hydrothermally altered basalts within the Krafla caldera. The oxygen and hydrogen isotope characteristics of metamorphic fluids recorded in alteration minerals have applications to fossil metasomatic systems as well as modern ones. Serpentinites from the [greater than or equal to] 3.8 Ga Isua Supracrustal Belt (ISB) of West Greenland locally preserve isotope characteristics of their original formation by seawater alteration of ocean crust and suggest that the early Archaean oceans had oxygen isotopes comparable to modern day seawater, but a hydrogen isotope composition that is lower than modern seawater by 25 ± 5%. The hydrogen isotopes of Archaean oceans places mass balance constraints on the extent of hydrogen escape before the rise of atmospheric oxygen ~2.5 Ga, and by extension the maximum atmospheric methane levels during the early Archaean. The oxygen isotope composition predicted by these serpentinites suggests that the ocean was isotopically buffered by hydrothermal interaction with ocean crust by 3.8 Ga. Finally, chromian muscovite-quartz-carbonate veins in the ISB have oxygen and hydrogen stable isotope, elemental and mineralogical characteristics that are genetically similar to orogenic gold deposits in the fore-arc regions of Phanerozoic accretionary margins. We show that in both modern orogens and in the supracrustal sequence at Isua, these veins are the result of seawater-derived fluids liberated from subducting lithosphere interacting with ultramafic rocks in the mantle wedge and lower crust, before migrating up crustal-scale vertical fracture zones. The presence of these veins in the ISB and other Archaean-age deposits indicates that plate tectonic processes comparable to modern-day subduction existed as early as 3.8 Ga.
Author: Hugh Rollinson
Publisher: Cambridge University Press
ISBN: 1108803822
Category : Science
Languages : en
Pages : 359
Get Book Here
Book Description
This textbook is a complete rewrite, and expansion of Hugh Rollinson's highly successful 1993 book Using Geochemical Data: Evaluation, Presentation, Interpretation. Rollinson and Pease's new book covers the explosion in geochemical thinking over the past three decades, as new instruments and techniques have come online. It provides a comprehensive overview of how modern geochemical data are used in the understanding of geological and petrological processes. It covers major element, trace element, and radiogenic and stable isotope geochemistry. It explains the potential of many geochemical techniques, provides examples of their application, and emphasizes how to interpret the resulting data. Additional topics covered include the critical statistical analysis of geochemical data, current geochemical techniques, effective display of geochemical data, and the application of data in problem solving and identifying petrogenetic processes within a geological context. It will be invaluable for all graduate students, researchers, and professionals using geochemical techniques.
Author: Matthew J. Kohn
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110561891
Category : Science
Languages : en
Pages : 596
Get Book Here
Book Description
Petrochronology is a rapidly emerging branch of Earth science that links time (ages or rates) with specific rock-forming processes and their physical conditions. It is founded in petrology and geochemistry, which define a petrogenetic context or delimit a specific process, to which chronometric data are then linked. This combination informs Earth’s petrogenetic processes better than petrology or geochronology alone. This volume and the accompanying short courses address three broad categories of inquiry. Conceptual approaches chapters include petrologic modeling of multi-component chemical and mineralogic systems, and development of methods that include diffusive alteration of mineral chemistry. Methods chapters address four main analytical techniques, specifically EPMA, LA-ICP-MS, SIMS and TIMS. Mineral-specific chapters explore applications to a wide range of minerals, including zircon (metamorphic, igneous, and detrital/Hadean), baddeleyite, REE minerals (monazite, allanite, xenotime and apatite), titanite, rutile, garnet, and major igneous minerals (olivine, plagioclase and pyroxenes). These applications mainly focus on metamorphic, igneous, or tectonic processes, but additionally elucidate fundamental transdisciplinary progress in addressing mechanisms of crystal growth, the chemical consequences of mineral growth kinetics, and how chemical transport and deformation affect chemically complex mineral composites. Most chapters further recommend areas of future research.
Author: A.M. Davis
Publisher: Elsevier
ISBN: 0080525350
Category : Science
Languages : en
Pages : 755
Get Book Here
Book Description
Volume 1 provides a broad overview of the chemistry of the solar system. It includes chapters on the origin of the elements and solar system abundances, the solar nebula and planet formation, meteorite classification, the major types of meteorites, important processes in early solar system history, geochemistry of the terrestrial planets, the giant planets and their satellite, comets, and the formation and early differentiation of the Earth. This volume is intended to be the first reference work one would consult to learn about the chemistry of the solar system.Reprinted individual volume from the acclaimed Treatise on Geochemistry (10 Volume Set, ISBN 0-08-043751-6, published in 2003)
Author: Philip A. E. Pogge von Strandmann
Publisher: Cambridge University Press
ISBN: 1108997627
Category : Science
Languages : en
Pages : 51
Get Book Here
Book Description
Lithium isotopes are a relatively novel tracer of present and past silicate weathering processes. Given that silicate weathering is the primary long-term method by which CO2 is removed from the atmosphere, Li isotope research is going through an exciting phase. We show the weathering processes that fractionate dissolved and sedimentary Li isotope ratios, focusing on weathering intensity and clay formation. We then discuss the carbonate and silicate archive potential of past seawater δ7Li. These archives have been used to examine Li isotope changes across both short and long timescales. The former can demonstrate the rates at which the climate is stabilised from perturbations via weathering, a fundamental piece of the puzzle of the long-term carbon cycle.
Author: F.T. Mackenzie
Publisher: Elsevier
ISBN: 0080525229
Category : Science
Languages : en
Pages : 448
Get Book Here
Book Description
This volume covers the formation and biogeochemistry of a variety of important sediment types from their initial formation through their conversion (diagenesis) to sedimentary rocks. The volume deals with the chemical, mineralogical, and isotopic properties of sediments and sedimentary rocks and their use in interpreting the environment of formation and subsequent events in the history of sediments, and the nature of the ocean-atmosphere system through geological time. Reprinted individual volume from the acclaimed Treatise on Geochemistry, (10 Volume Set, ISBN 0-08-043751-6, published in 2003). - Comprehensive and authoritative scope and focus - Reviews from renowned scientists across a range of subjects, providing both overviews and new data, supplemented by extensive bibliographies - Extensive illustrations and examples from the field
Author: Peter A. Rona
Publisher: Springer Science & Business Media
ISBN: 1489904026
Category : Technology & Engineering
Languages : en
Pages : 802
Get Book Here
Book Description
During the past ten years, evidence has developed to indicate that seawater convects through oceanic crust driven by heat derived from creation of lithosphere at the Earth-encircling oceanic ridge-rift system of seafloor spreading centers. This has stimulated multiple lines of research with profound implications for the earth and life sciences. The lines of research comprise the role of hydrothermal convection at seafloor spreading centers in the Earth's thermal regime by cooling of newly formed litho sphere (oceanic crust and upper mantle); in global geochemical cycles and mass balances of certain elements by chemical exchange between circulating seawater and basaltic rocks of oceanic crust; in the concentration of metallic mineral deposits by ore-forming processes; and in adaptation of biological communities based on a previously unrecognized form of chemosynthesis. The first work shop devoted to interdisciplinary consideration of this field was organized by a committee consisting of the co-editors of this volume under the auspices of a NATO Advanced Research Institute (ARI) held 5-8 April 1982 at the Department of Earth Sciences of Cambridge University in England. This volume is a product of that workshop. The papers were written by members of a pioneering research community of marine geologists, geophysicists, geochemists and biologists whose work is at the stage of initial description and interpretation of hydrothermal and associated phenomena at seafloor spreading centers.
Author: Jochen Hoefs
Publisher: Springer Science & Business Media
ISBN:
Category : Science
Languages : en
Pages : 230
Get Book Here
Book Description
Stable Isotope Geochemistry is an introduction to the use of stable isotopes in the geosciences. It is subdivided into three parts: - theoretical and experimental principles; - fractionation mechanisms of light and heavy elements; - the natural variations of geologically important reservoirs. The 5th edition has been revised and extended and now includes a new chapter on palaeoclimatology. Special emphasis has been given to the growing field of "heavy" elements. Many new references have been added, which will enable quick access to recent literature. 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.
Author: Beth N. Orcutt
Publisher: Cambridge University Press
ISBN: 1108477496
Category : Nature
Languages : en
Pages : 687
Get Book Here
Book Description
A comprehensive guide to carbon inside Earth - its quantities, movements, forms, origins, changes over time and impact on planetary processes. This title is also available as Open Access on Cambridge Core.
Author: R.C. Newton
Publisher: Springer Science & Business Media
ISBN: 1461258715
Category : Science
Languages : en
Pages : 312
Get Book Here
Book Description
Today large numbers of geoscientists apply thermodynamic theory to solu tions of a variety of problems in earth and planetary sciences. For most problems in chemistry, the application of thermodynamics is direct and rewarding. Geoscientists, however, deal with complex inorganic and organic substances. The complexities in the nature of mineralogical substances arise due to their involved crystal structure and multicomponental character. As a result, thermochemical solutions of many geological-planetological problems should be attempted only with a clear understanding of the crystal-chemical and thermochemical character of each mineral. The subject of physical geochemistry deals with the elucidation and application of physico-chemical principles to geosciences. Thermodynamics of mineral phases and crystalline solutions form an integral part of it. Developments in mineralogic thermody namics in recent years have been very encouraging, but do not easily reach many geoscientists interested mainly in applications. This series is to provide geoscientists and planetary scientists with current information on the develop ments in thermodynamics of mineral systems, and also provide the active researcher in this rapidly developing field with a forum through which he can popularize the important conclusions of his work. In the first several volumes, we plan to publish original contributions (with an abundant supply of back ground material for the uninitiated reader) and thoughtful reviews from a number of researchers on mineralogic thermodynamics, on the application of thermochemistry to planetary phase equilibria (including meteorites), and on kinetics of geochemical reactions.
