Download or read book Tholeiitic Magmatism in the Belingwe Greenstone Belt Zimbabwe written by Chris Brake and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Geology of the Belingwe Greenstone Belt Zimbabwe written by M.J. Bickle and published by CRC Press. This book was released on 2020-08-26 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study on the Bellingwe Greenstone Belt, presenting the stratigraphy of the belt, its structure and tectonic setting, the sedimentology of what may be a rift basin, the geochemistry of the freshest Archaean komatiites yet found, and models of the evolution of the region.
Download or read book Precambrian Ophiolites and Related Rocks written by T.M. Kusky and published by Elsevier. This book was released on 2004-10-26 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent developments have shown that many full and partial ophiolites are preserved in Precambrian cratons. This book provides a comprehensive description and discussion of the field aspects, geochemistry, geochronology and structure of the best of these ophiolites. It also presents syntheses of the characteristics of ophiolites of different ages, and an analysis of what the characteristics of these ophiolites mean for the thermal and chemical evolution of the earth. This title emphasizes new studies of Precambrian Geology that have documented ophiolites, ophiolitic fragments, and ophiolitic melanges in many Precambrian terranes. Each chapter focuses on individual Precambrian ophiolites or regions with numerous Precambrian ophiolites, and covers field aspects, petrology, geochemistry, geochronology, and other descriptive aspects of these ophiolites, it also delves into more theoretical and speculative aspects about the interpretation of the significance of these ancient ophiolites.
Download or read book Theleiitic Magmatism in the Belingwe Greenstone Belt written by C. Brake and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Archaean Mafic Magmatism and Crust Formation in the Eastern Pilbara Craton Western Australia and Belingwe Greenstone Belt Zimbabwe written by Robert Bolhar and published by . This book was released on 2001 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Early Earth written by C. M. R. Fowler and published by Geological Society of London. This book was released on 2002 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Early Precambrian Basic Magmatism written by R.P. Hall and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Basic magmatic rocks make up approximately three-quarters of the crust ofthe present day Earth. Because we can observe and study the volcanic products of present day tectonic regimes comprehensively, we can shed light on ancient tectono-magmatic provinces, and thereby deduce the petrogenesis and evolution of the oldest basic rocks. This is the primary objective of this book. The book was conceived in order to provide a comprehensive review of the basic rocks produced during the first half of the Precambrian, i.e. the Archaean and early Proterozoic, to about 1.8 Ga years ago. Two major questions are addressed. First, what basic magmas were generated during the early Precambrian: were these magmas globally uniform, and to what extent were prevailing tectonic controls and compo sitions analogous to those of the present day? Clearly, this can be answered only by bringing together fundamental information about all relevant basic magmatic events. Second, is there any systematic temporal variation in the nature of basic suites, and what implications might such variations have on our interpretations of early Earth history? Are there important differences between early Archaean, late Archaean, Proterozoic and modern basic magmatic suites? The book uses two approaches to address these questions. Early chapters examine the fundamental characteristics of these basic rocks, whilst later chapters assess regional distribution and development by providing an overview of each major early Precambrian craton.
Download or read book Journal of African Earth Sciences written by and published by . This book was released on 2002 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Tale of Two Cratons written by A. G. Jones and published by Gulf Professional Publishing. This book was released on 2004-03-11 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given the established nature of geoscientific knowledge of the Kaapvaal craton compared to the Slave craton, and given the exciting new interdisciplinary results coming from the Kaapvaal Project and from Slave craton studies, scientists working on both cratons were brought together in a workshop to compare and contrast the nature of these two cratons. Of the 54 papers presented at the workshop, 24 are included in this volume. There are clearly major similarities and differences between these two Archean cratons. The crust of both was predominantly formed in the Mesoarchean. Both contain crustal sections consisting of terranes of different ages welded together by Archean accretionary events. Both crustal sections are underlain by lithospheric mantle sections consisting of peridotites that experienced extensive partial melt extraction between 2.9 Ga and 3.2 Ga, but this is where the similarities between the cratons end. One of the most striking differences between the Slave and Kaapvaal cartons is the apparent seismic homogeneity of the Kaapvaal craton's SCLM whereas the Slave craton is seismically layered. The seismic layering in the centre of the craton correlates laterally and with depth with electrical layering and geochemical layering. Taken together, these differences suggest that SCLM formation was different for the two cratons, implying that the search for a single causative formation process is bound to fail. Reprinted from the journal Lithos Volume 71, numbers 2-4.
Download or read book Mineralogical Magazine written by and published by . This book was released on 1994 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Tectonic Setting of the Belingwe Greenstone Belt Zimbabwe written by Morag Hunter and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Geology and Geochemistry of the Ngezi Group Volcanics Belingwe Greenstone Belt Zimbabwe written by Stephen Philip Scholey and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book V M Goldschmidt Conference Extended Abstracts written by and published by . This book was released on 1994 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Gravity Study of the Belingwe Greenstone Belt written by R. T. Ranganai and published by . This book was released on 1985* with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Geology of the Belingwe Shabani Schist Belt written by A. Martin and published by . This book was released on 1978 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Geology Geochemistry and Metallogeny of the Tati Greenstone Belt Northeastern Botswana written by Akolang Russia Tombale and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Tati Greenstone Belt of Botswana occurs along the southern margin of the Archean Zimbabwe Craton in the northern contact zone of the Limpopo Belt Detailed mapping and structural analysis indicates that the Tati Greenstone Belt consists of three fault-bounded volcano-plutonic sequences intruded by granitoids. The data further suggest that the belt formed from the accretion of the volcano- plutonic sequences to the Zimbabwe Craton La a manner resembling modem orogenic belts. -- Geochemical data suggest that the Tati Greenstone Belt consists of a komatiite-tholeiite sequence representing a back-arc basin and calc-alkaline volcanic and feldspathic sedimentary rock sequences which overall indicate the existence of an arc environment The geochemical data further indicate the presence of three different magmatic suites within the Lady Mary Group of the Tati Greenstone Belt and these suites have geochemical signatures similar to those of found in modem tectonic environments. The three magmatic suites include LREE-depleted rocks, LREE-enriched rocks and komatiites. The LREE-enriched rocks form the margins of a basinal structure with LREE-depleted and komatiites at the core. The komatiites are postulated to have formed from plume-type magmas generated in deep portions of the Archean mantle. -- Gold mineralization in the Tati Greenstone Belt northeastern Botswana, formed as an integral component of the tectonic evolution of the belt Three main stages of gold mineralization are recognized. The first mineralization stage is related to the late stages of volcanism which formed the volcanic sequences in the belt during this stage hydrothermal fluids circulated through the volcanic structure along fissures, fractures and lithological boundaries, leaching metals and creating extensive carbonate alteration zones. The contact zones between basaltic rocks and synvolcanic gabbroic sills, and inter-pillow areas were the most extensively altered. Metal-bearing fluids, in which the metals were derived during the alteration of the basaltic crust, were discharged along the tops of the volcanic sequences depositing banded iron formations with siliceous, carbonate, oxide and sulphide fades. In particular, sulphide fades banded iron formations in the Tati Greenstone Belt are discontinuous units located at the top of major volcanic sequences, which are either covered by sedimentary rocks including carbonates and minor clastic rocks, or lie directly on the basaltic crust In the waning stages of the hydrothermal activity, lower temperature phases of the hydrothermal fluids precipitated Au, Ag, Sb, As and other related metals in pockets at localized sites. -- The second stage of gold mineralization coincided with the deformation of the belt and the creation of favourable structural sites. During this stage, related to NE to N directed compression and thrusting (D1), NE to N verging recumbent and overturned folds were formed. Volcanic sequences were thrust onto each other along lithological boundary-parallel faults, which are demarked by banded iron formations and related sedimentary rocks. The second deformation, D2, was the main foliation-forming deformation event Metamorphic de-watering during this event resulted in large scale foliation-parallel carbonate and quartz-carbonate veining. Carbonate alteration formed during the first stage was extensively replaced by silica during this second stage, creating the silicified alteration zones which accommodated brittle deformation during subsequent deformation events. -- The third stage of gold mineralization was related to D3 shearing of the volcanic rocks in the belt and major granitoid magmatism. Shearing and faulting created cross stratigraphy faults/shear zones. Banded iron formations and silicified zones formed during the D2 deformational event accommodated brittle failure during this D3 shearing event. Secondary fluids penetrated through the lithologies along numerous structures and were heated by granitoid magmas. These fluids remobilized metals from banded iron formations and massive sulphide horizons, redepositing them into brittle fractures. The brittle structures were localised to areas of lithological heterogeneity, such as at contacts between gabbroic sills and basaltic host rocks and in relatively structurally competent rocks such as banded iron formations. The mineral occurrences formed during this stage were low temperature Au-only deposits. -- Gold was produced from at least 70 small mines scattered across the Tati Greenstone Belt Pre-1800 gold production by local tribesmen was also substantial. The various gold occurrences and their characteristics are summarized in a metallogenic map of the belt. Data presented on the metallogenic map include the main commodity produced, metallic associations, the form in which gold occurs, host rock type, and the nature of the structural control.
Download or read book Gondwana Research written by and published by . This book was released on 1997 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
