Download or read book Possible Evidence for Fluid rock Oxygen Isotope Disequilibrium in Hydrothermal Systems written by and published by . This book was released on 1992 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is ample evidence from geothermal systems that isotope temperatures estimated from the oxygen isotope fractionation between alteration phases and coexisting aquifer fluids agree closely with measured bore-hole temperatures. Similar, but limited evidence is found in epithermal vein deposits where isotopes temperature agree well with fluid inclusion homogenization temperature. Conversely, many hydrothermal systems exhibit varying degrees of fluid-rock oxygen isotope equilibration. There appears to be a crude relationship between increasing degree of equilibrium and increasing temperature and salinity. The observed variations in the degree of exchange may have resulted from local, self-sealing of the fracture network prior to equilibration. The ability for fracture to remain open or to propogate allowing continued fluid flow may be the deciding factor in the attainment of isotopic equilibration.
Download or read book Hydrogen and Oxygen Isotope Fractionation in Hydrous Minerals as Indicators of Fluid Source in Modern and Fossil Metasomatic Environments written by Emily Catherine Pope and published by Stanford University. This book was released on 2011 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Water rock Ratio Calculations in Hydrothermal Systems written by Pier Anne de Groot and published by . This book was released on 1997 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrogen and Oxygen Isotope Fractionation in Hydrous Minerals as Indicators of Fluid Source in Modern and Fossil Metasomatic Environments written by Emily Catherine Pope and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 754 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Oxygen Isotope Fluid Inclusion and Mineralogy Study of the Ancient Hydrothermal Alteration in the Grand Canyon of the Yellowstone River Yellowstone National Park Wyoming written by Allison R. Phillips and published by . This book was released on 2010 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evidence for Replacement of Dilute Hydrothermal Solutions by Hot Hypersaline Brine in the Northeastern Part of the Salton Sea Geothermal System California written by Charles Steger Oakes and published by . This book was released on 1988 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water rock Interaction Low temperature environments written by Yousif K. Kharaka and published by Taylor & Francis. This book was released on 1992 with total page 856 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1992. Routledge is an imprint of Taylor & Francis, an informa company.
Download or read book Using Geochemical Data written by Hugh Rollinson and published by Cambridge University Press. This book was released on 2021-05-06 with total page 359 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Separation of Isotopes of Biogenic Elements in Two phase Systems written by Boris Mikhailovich Andreev and published by Elsevier. This book was released on 2006-12-01 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Separation of Isotopes of Biogenic Elements provides a detailed overview of this area of research covering all aspects from the value of isotope effects to their practical use (equilibrium single-stage isotope effect - kinetics and mass transfer – multiplication of the single-stage isotope separation factor - technological peculiarity of processes) with the purpose of extraction from the natural mixture of the enriched and highly concentrated isotopes. In contrast to traditional books on the theory of isotope separation, the theoretical part of the book describes separation in two-phase processes in counter-flow columns. The experimental part of the book presents systematic analysis of specialists in the field of isotope separation in counter-flow columns. This book will be of interest to scientists, engineers and technical workers engaged in isotope separation processes and isotope application in nuclear physics, medicine, agro-chemistry, biology and other areas. This book may also be used in teaching theory and practical aspects in courses on physical chemistry and Isotope separation of light elements by physicochemical methods. * summarises current state of isotope research, especially biogenic elements* covering all aspects from the value of isotope effects to their practical use* of interest to scientists, engineers and technical workers engaged in isotope separation processes and isotope application
Download or read book Stable Isotopes in High Temperature Geological Processes written by John W. Valley and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 16 of Reviews in Mineralogy inroduces to high-temperature stable isotope geochemistry and should provide an entry into the pertinent literature, as well as some understanding of the basic concepts and potential applications. The first three chapters focus on the theory and experimental data base for equilibrium, disequilibrium, and kinetics of stable isotope exchange reactions among geologically important minerals and fluids. The fourth chapter discusses the primordial oxygen isotope variations in the solar system prior to formation of the Earth, along with a discussion of isotopic anomalies in meteorites. The fifth chapter discusses isotopic variations in the Earth's mantle and the sixth chapter reviews the variations in the isotopic compositions of natural waters on our planet. In Chapters 7, 8, 9 and 10, these isotopic constraints and concepts are applied to various facets of the origin and evolution of igneous rocks, bringing in much material on radiogenic isotopes as well, because these problems require a multi-dimensional attack for their solution. In Chapters 11 and 12, the problems of hydrothermal alteration by meteoric waters and ocean water are considered, together with discussions of the physics and chemistry of hydrothermal systems and the 18O/16O history of ocean water. Finally, in Chapters 13 and 14, these concepts are applied to problems of metamorphic petrology and ore deposits, particularly with respect to the origins of the fluids involved in those processes.
Download or read book Triple Oxygen Isotopes written by Huiming Bao and published by Cambridge University Press. This book was released on 2019-08-29 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The 'detective' power of stable isotopes for processes that occurred in the past, and for elucidating mechanisms at the molecular level, has impressed researchers over the past 100 years, since the time when isotopes of elements were first discovered. While most are interested in the normalized abundance ratios of two isotopes of an element, further power was unleashed when researchers investigated the relationship of three or more isotopes of the same element, e.g. 16O, 17O, and 18O for oxygen. This Element focuses on the history of discovery of triple isotope effects, the conceptual framework behind these effects, and major lines of development in the past few years of triple oxygen isotope research.
Download or read book Zentralblatt f r Mineralogie written by and published by . This book was released on 1995 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stable Isotope Investigation of Fluids and Water rock Interaction in the Roosevelt Hot Springs Thermal Area Utah written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Carbon-hydrogen-oxygen isotope compositions have been measured in regional cold waters, geothermal fluids, and hydrothermally altered rocks from the Roosevelt Hot Springs geothermal area. These data have been used, in conjunction with other geological and geochemical data from this geothermal system, to place some limits on the origin of geothermal fluids and reservoir carbon, the fluid recharge area, physical-chemical environment of hydrothermal alteration, and relative permeability of the geothermal system. The similarity of hydrogen isotope compositions of local meteoric water and geothermal reservoir fluid indicate that the geothermal fluids are virtually entirely of surface derivation. An isotopically reasonable source area would be the Mineral Mountains directly to the east of the Roosevelt system. Hydrothermal calcite appears to be in isotopic equilibrium with the deep reservoir fluid. The deltaC/sup 13/ values of deep calcites and T- pH-f0/sub 2/ conditions of the reservoir defined by measured temperature, fluid chemistry, and alteration mineralogy fix the delta/sup 13/C value of the geothermal system to -5 to -6.5% (PDB). These values do not unambiguously define any one source or process, however. There is a relatively small increase in /sup 18/O of geothermal fluids relative to their cold surface water precursors and significant /sup 18/O depletion accompanying hydrothermal alteration of the granitic host rock. These isotopic shifts indicate a high ratio of geothermal fluid to altered rock for the geothermal system, implying relatively rapid (geologically) recirculation rates and significant permeability of the geothermal system.
Download or read book Stable Isotope Geochemistry written by John W. Valley and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 43 of Reviews in Mineralogy and Geochemistry follows the 1986 Reviews in Mineralogy (Vol. 16) in approach but reflects significant changes in the field of Stable Isotope Geochemistry. In terms of new technology, new sub-disciplines, and numbers of researchers, the field has changed more in the past decade than in any other since that of its birth. Unlike the 1986 volume, which was restricted to high temperature fields, this book covers a wider range of disciplines. However, it would not be possible to fit a comprehensive review into a single volume. Our goal is to provide state-of-the-art reviews in chosen subjects that have emerged or advanced greatly since 1986. This volume was prepared for Short Course on Stable Isotope Geochemistry presented November 2-4, 2001 in conjunction with the annual meetings of the Geological Society of America in Boston, Massachusetts.
Download or read book The Il maussaq Alkaline Complex South Greenland written by Henning Sørensen and published by . This book was released on 2001 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamics of Minerals and Melts written by R.C. Newton and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
