[PDF] Structurally Controlled Magmatic Hydrothermal Model For Archean Lode Gold Deposits eBook

Author : Alain Chauvet
Publisher : MDPI
Page : 256 pages
File Size : 12,99 MB
Release : 2019-04-16
Category : Science
ISBN : 3038977845

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"Structural Control” remains a crucial point that frequently lacks in any scientific and/or economic analysis of ore deposits, whatever their type and class. The case of lode deposits is exemplary, although also other deposits, like breccia pipe, stockwerk, massive sulphides, skarn, etc., can, surprisingly, be concerned. Several concepts like the gold-bearing shear zone have not proven valid during the last few decades in terms of our understanding of gold deposit and have been totally abandoned. Additionally, the relationships between magmatism, regional tectonic context, and mineralization remain uncertain and have been debated in several recent publications. This demonstrates that this issue is still relevant, and its solution may help in the distinction between intrusion-related and orogenic deposits. In this Special Issue, we particularly invite any case study of mineral deposits, in which it has been demonstrated that structural geology may have a significant role in the establishment of the deposit model of formation and/or on exploration and exploitation programs. Examples in which the structural model diverges from those described in the classical literature are particularly welcomed, including studies in which relationships with magmatism can be suspected and/or demonstrated. Indeed, all cases that illustrate concepts that differ from the classic ones and from theoretical models may represent significant contributions to this volume.

Author : Karen D. Kelley
Publisher :
Page : pages
File Size : 14,90 MB
Release : 2014
Category : Prospecting
ISBN : 9781629499291

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Earth's near-surface mineralogy has diversified over more than 4.5 b.y. from no more than a dozen preplanetary refractory mineral species (what have been referred to as "ur-minerals" by Hazen et al., 2008) to around 5,000 species (based on the list of minerals approved by the International Mineralogical Association; http://rruff.info/ima). This dramatic diversification is a consequence of three principal physical, chemical, and biological processes: element selection and concentration (primarily through planetary differentiation and fluidrock interactions); an expanded range of mineral-forming environments (including temperature, pressure, redox, and activities of volatile species); and the influence of the biosphere.

Author : Ulrich Kretschmar
Publisher : Elsevier
Page : 356 pages
File Size : 12,45 MB
Release : 2015-11-24
Category : Science
ISBN : 0128032235

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The Metallogeny of Lode Gold Deposits: A Syngenetic Perspective is a synthesis of lode gold vein forming processes, addressing the commonality in similar worldwide deposits. The book’s empirical model incorporates widely known and accepted principles of ore deposition and shows how it applies in the volcanic-sedimentary greenstone belt environment. Several chapters detail outcrop maps and photos of field occurrences and textures. The interpretations flow directly from the authors’ field work, and are coupled with analyses of underlying physical processes. Utilizing detailed geological mapping, field work, and chemical analyses as the basis of a syngenetic formation mode, the text arms readers with the tools necessary to accurately analyze and interpret new data on the subject. This includes information on decoding the significance of asymmetry in vein formation, as well as the role of lamprophyres in gold camps, how Archean geology requires integration into a lode vein formation model, and how to develop an understanding of the worldwide applicability of gold cycles to lode vein formation and exploration and how it can be applied to deposits of all ages. Presents the first book to galvanize lode gold research into a single authoritative reference Simplifies the complexity of lode gold’s underlying processes and presents valid concepts surrounding the lode gold forming environment Features color figures, illustrations, and photos that enrich the content’s focus and aid in the retention of key concepts

Author : Paul Kibler Sims
Publisher :
Page : 28 pages
File Size : 19,58 MB
Release : 1992
Category : Geology, Stratigraphic
ISBN :

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The Canadian segment of the Archean Superior province is a major world source of lode gold. The gold deposits occur in or near regional transcurrent and oblique slip-shear deformation zones that comprise a conjugate set to a northwest- directed compression of the Superior province. These structures provided permeable pathways for the flow of large volumes of auriferous fluid derived from an external source. Historic gold production from the United States segment of the Superior province is modest, but the close similarity in the geologic environment of the United States and Canadian segments suggests that large gold deposits should be present in the U.S.A. An occurrence model largely based on known parameters of gold mineralization in Canada suggests that the greenstone-granite terranes of the Wawa and Wabigoon sub-provinces in the United States are favorable for important gold deposits. The model suggests that gold mineralization took place during or later than the transcurrent faulting and that it took place contemporaneously with emplacement of silica-undersaturated intrusions. The faulting occurred late in the igneous-tectonic history of the Superior province, about 2,690 Ma. Extensive, intense alteration comprising carbonitization, silicification, and sulfidization accompanied the gold mineralization. The relationships between alteration minerals and mineralized veins suggest a close temporal relationship between the alteration and gold mineralization processes. The proposed occurrence model for gold mineralization and the available data suggest that two broad regions of greenstone in the Archean Superior province in north-central United States are particularly favorable for gold deposits: (1) the Upper Peninsula of Michigan, and (2) northeastern Minnesota. The Ishpeming greenstone belt of the Wawa subprovince in Michigan contains the important Ropes deposit and several other known gold occurrences, and the Vermilion district (Wawa subprovince) in northeastern Minnesota contains highly anomalous gold in soils and minor known bedrock occurrences. Transcurrent faults in both areas should be favorable sites for gold mineralization

Author : R. P. Foster
Publisher : Springer Science & Business Media
Page : 447 pages
File Size : 15,70 MB
Release : 2012-12-06
Category : Science
ISBN : 1461304970

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Within the last decade, the high and continuing demand for gold has prompted a global gold rush on a scale never before seen, not even in the heady days of Ballarat, California and the Yukon. Gold is being sought on every continent and, with very few exceptions, in every country around the world. Such interest and fierce competition has demanded considerable innovation and improvement in exploration techniques paralleled by a rapid expansion of the geological database and consequent genetic modelling for the many different types of gold deposits now recognized. This proliferation of data has swamped the literature and left explorationist and academic alike unable to sift more than a small proportion of the accumulating information. This new book represents an attempt to address this major problem by providing succinct syntheses ofall major aspects ofgold metallogeny and exploration, ranging from the chemical distribution of gold in the Earth's crust, and the hydrothermal chemistry of gold, to Archaean and Phanerozoic lode deposits, epithermal environments, chemical sediments, and placer deposits, and culminates in chapters devoted to geochemical and geophysical exploration, and the economics of gold deposits. Each chapter is written by geoscientists who are acknowledged internationally in their respective fields, thus guaranteeing a broad yet up-to-date coverage. In addition, each chapter is accompanied by reference lists which provide readers with access to the most pertinent and useful publications.

Author : Kula Misra
Publisher : Springer Science & Business Media
Page : 857 pages
File Size : 39,21 MB
Release : 2012-12-06
Category : Science
ISBN : 9401139253

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Mineral deposits have supplied useful or valuable material for human consumption long before they became objects of scientific curiosity or commercial exploitation. In fact, the earliest human interest in rocks was probably because of the easily accessible, useful (e. g. , red pigment in the form of earthy hematite) or valuable (e. g. , native gold and gemstones) materials they contained at places. In modem times, the study of mineral deposits has evolved into an applied science employing detailed field observations, sophisticated laboratory techniques for additional information, and computer modeling to build complex hypotheses. Understanding concepts that would someday help geologists to find new mineral deposits or exploit the known ones more efficiently have always been, and will continue to be, at the core of any course on mineral deposits, but it is a fascinating subject in its own right, even for students who do not intend to be professional economic geologists. I believe that a course on mineral deposits should be designed as a "capstone course" that illustrates a comprehensive application of concepts from many other disciplines in geology (mineralogy, stratigraphy and sedimentation, structure and tectonics, petrology, geochemistry, paleontology, geomorphology, etc. ). This book is intended as a text for such an introductory course in economic geology, primarily for senior undergraduate and graduate students in colleges and universities. It should also serve as a useful information resource for professional economic geologists.

Author : Liqiang Yang
Publisher : MDPI
Page : 538 pages
File Size : 36,66 MB
Release : 2019-09-18
Category : Science
ISBN : 3039212931

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Within the last decade, the high and continuing demand for precious and base metals, as well as critical elements, has prompted a global rush on a scale never before seen. This eventually resulted in the demand for considerable innovation and improvement in mineral deposit genetic modelling and ore formation regimes for the many different types of gold deposits, now recognized, and paralleled by the wide employment of exploration techniques and a rapid expansion of geological databases. This Special Issue will show case studies of porphyry polymetal systems, orogenic gold formations, water–rock reaction, ore-forming structure evolution, mineralogy and petrology of ore deposit, ore formation regime, geochronology and geochemistry of ore deposit, ore-forming evolution, mineral exploration and cutting-edge technology in ore deposit study.