Download or read book Detrital Uraninite from the Witwatersrand Basin South Africa written by Anne Herzenberg and published by . This book was released on 1978 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geological Survey Professional Paper written by Geological Survey (U.S.) and published by . This book was released on 1981 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uranium thorium bearing Silicates in Reefs of the Witwatersrand South Africa written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: (U-Th)-silicates are extremely rare in most ore-bearing conglomerates in the Witwatersrand. However, authigenic coffinite is fairly common in the Dominion Reef, the oldest conglomerate in the Witwatersrand Basin, and on the West Rand Goldfield, in reefs in the uppermost part of the Witwatersrand Supergroup. The coffinite was formed in situ from detrital uraninite through the uptake of silica. Thorite and thorogummite of detrital origin also are present in the Dominion Reef. Chemical data indicate that (U,Th)-silicates form two complete series of anhydrous and hydrated species, for which the general formulae are (U,Th)SiO4 and (U,Th)SiO4.nH2O (n less than 4), respectively. On the basis of existing names, the end members of the anhydrous series are anhydrous coffinite and thorite, and those of the hydrated series are coffinite and thorogummite.
Download or read book Evolution of Early Earth s Atmosphere Hydrosphere and Biosphere written by Stephen E. Kesler and published by Geological Society of America. This book was released on 2006-01-01 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The history of Earth's early atmosphere, hydrosphere, and biosphere, from Hadean through Proterozoic time, is one of geology's enduring puzzles. Ore deposits provide important insights into this history because they contain elements and minerals that are highly sensitive to the geochemical environment in which they form. Just what these minerals tell us remains a matter of considerable debate, however. When and how did life develop, an oxygen-rich atmosphere form, and sulfate dominate the ocean? This volume contains reports on these questions from both sides of the aisle for iron and manganese formations, uranium paleoplacers and hydrothermal deposits, and exhalative sulfides and oxides."--Publisher's website.
Download or read book Geological Survey Professional Paper written by and published by . This book was released on 1981 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geological Survey Professional Paper written by and published by . This book was released on 1981 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uranium in South Africa 1946 1956 written by Associated Scientific and Technical Societies of South Africa and published by . This book was released on 1957 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geological Survey Professional Paper written by Geological Survey (U.S.) and published by . This book was released on 1981 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uranium Distribution in Early Precambrian Gold bearing Conglomerates of the Kaapvaal Craton South Africa written by K. Thiel and published by . This book was released on 1979 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Treatise on Geochemistry written by and published by Newnes. This book was released on 2013-10-19 with total page 14787 pages. Available in PDF, EPUB and Kindle. Book excerpt: This extensively updated new edition of the widely acclaimed Treatise on Geochemistry has increased its coverage beyond the wide range of geochemical subject areas in the first edition, with five new volumes which include: the history of the atmosphere, geochemistry of mineral deposits, archaeology and anthropology, organic geochemistry and analytical geochemistry. In addition, the original Volume 1 on "Meteorites, Comets, and Planets" was expanded into two separate volumes dealing with meteorites and planets, respectively. These additions increased the number of volumes in the Treatise from 9 to 15 with the index/appendices volume remaining as the last volume (Volume 16). Each of the original volumes was scrutinized by the appropriate volume editors, with respect to necessary revisions as well as additions and deletions. As a result, 27% were republished without major changes, 66% were revised and 126 new chapters were added. In a many-faceted field such as Geochemistry, explaining and understanding how one sub-field relates to another is key. Instructors will find the complete overviews with extensive cross-referencing useful additions to their course packs and students will benefit from the contextual organization of the subject matter Six new volumes added and 66% updated from 1st edition. The Editors of this work have taken every measure to include the many suggestions received from readers and ensure comprehensiveness of coverage and added value in this 2nd edition The esteemed Board of Volume Editors and Editors-in-Chief worked cohesively to ensure a uniform and consistent approach to the content, which is an amazing accomplishment for a 15-volume work (16 volumes including index volume)!
Download or read book The Sources of Witwatersrand Gold and Uranium written by Desmond A. Pretorius and published by . This book was released on 1989 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1980 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plate Tectonics Crustal Evolution written by Kent C. Condie and published by Elsevier. This book was released on 2013-10-22 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This substantially revised edition includes recently published information relating to plate tectonics and continental origin. A large number of new figures have been added, and new sections included on meteorites, seismic tomography, mantle convection, accretionary terranes, mantle sources and evolution, continental growth, secular changes in Earth history, also a new chapter on exogenic Earth systems. In addition the following topics have been substantially revised: lunar origin, global gravity, origin of the core, metamorphism, plate boundaries, hotspots, tectonic settings, and magma associations. Among the new features the Tectonic Map of the World has also been updated.
Download or read book Processes on the Early Earth written by W. U. Reimold and published by Geological Society of America. This book was released on 2006-01-01 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This Special Paper presents a collection of 19 papers contributed to a joint Field Forum organized by the Geological Society of America and the Geological Society of South Africa in July 2004 in the Barberton Greenstone Belt and the Vredefort Dome, South Africa. The papers cover a wide variety of themes, including Archean and Proterozoic crust formation and geodynamics (with an appraisal of evidence of Archean subduction processes); the significance of impacts in the evolution of the early Earth's crust; traces of early life in Archean environments of Australia and South Africa and related studies of depositional environments; and processes affecting the giant Witwatersrand gold deposit."--Publisher's website.
Download or read book Archean Crustal Evolution written by K.C. Condie and published by Elsevier. This book was released on 1994-11-11 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: The integration of Tectonics/Geochemistry, up-to-date reviews by leading scientists as well as a broad topical coverage of the Archean, are some of the features of this particular volume. As geochronology has progressed in the last 20 years, the Archean has continued to attract interest. Advancements in the understanding of Archean crustal and mantle evolution have progressed rapidly since the first International Archean Symposium in Western Australia (1970). The landmark for the Archean was the NATO Advanced Study Institute at Leicester (1975). At this meeting the Archean truly "came of age". Investigators from many different disciplines focused their expertise on the early history of the earth. For the first time, the nature of the atmosphere, oceans, and life during the Archean was an important part of an Archean symposium. During the most recent Archean Symposium in Perth in 1990, there was a shift in interest from field and trace element data to the new rapidly evolving high-precision U/Pb geochronology of Archean rocks and to detailed structural studies of both low and high grade Archean terrains. The terrane concept so widely applied to the Phanerozoic was proposed for the Archean Yilgarn Province in Western Australia and is now widely accepted for the Archean (as evident by the articles in this book). Plate tectonics is now widely accepted as the principal process that controls the history of continents and oceans. There are, though, well substantiated differences between Archean and post-Archean rocks that indicate that Archean tectonic regimes must have differed in some respects from modern ones. The question of how and to what degree did Archean plate tectonics differ from modern plate tectonics is treated in many of the chapters of this book. Altogether, the editor has presented a selection of articles that provide a fascinating insight into the latest observations in this field.
Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1981 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Asteroids Impacts Crustal Evolution and Related Mineral Systems with Special Reference to Australia written by Andrew Y. Glikson and published by Springer. This book was released on 2018-03-12 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive overview of Australian impact structures and related mineralization, including a discussion of the significance of many of these structures for crustal evolution. The book focuses in particular on Archaean impact ejecta/fallout units in the Pilbara Craton of Western Australia, large exposed and buried impact structures, and on the geophysical evidence for possible to probable impact structures. Thanks to their long-term geological stability, Precambrian and younger terrains in the Australian continent contain 38 confirmed impact structures and 43 ring and dome structures, many of which constitute possible to probable asteroid impact structures. The impact structures have been the subject of more than half a century of studies and range from several tens of meter-large craters to buried structures larger than 100 km in diameter. Discoveries of impact fallout units in the Pilbara Craton have defined the Pilbara as one of the two best documented terrains where Archaean impact ejecta/fallout deposits are identified, the other terrain being the Kaapvaal Craton in southern Africa. A synthesis of evidence from both cratons indicates periods of large asteroid bombardments during ~3.47 – 2.48 billion years-ago, including peak bombardment about 3.25—3.22 billion years-ago. The latter period coincides with an abrupt transformation of an early Archaean granite-greenstone crust to mid to late Archaean semi-continental crustal regimes, underpinning the significance of heavy asteroid impact events for crustal evolution. Apart from proven impact structures, Australian terrains display a range of circular features, including morphological and drainage rings, circular lakes, volcanic craters, tectonic domes, oval granite bodies, mafic igneous plugs, salt diapirs, and magnetic, gravity and seismic anomalies, many of which are of a likely impact origin. Thermal and hydrothermal processes associated with impact cratering bear important consequences for the formation of mineral deposits, such as Ni at Sudbury, Pb-Zn at Siljan and Kentland. Impact structures may also provide sites for the accumulation of hydrocarbons, whereas in some instances fracturing associated with impact structures allows outward migration of oil and gas.
