Gold-Transporting Hydrothermal Fluids in the Earth's Crust


Book Description

Hydrothermal ore deposits that are exploited for gold include both gold-only deposits, such as orogenic deposits, and gold-bearing examples of the common hydrothermal deposits types that are formed around upper-crustal magmatic centres, in particular porphyry and epithermal deposits. Fluid-inclusion data have shown that ore fluids of gold-only deposits are compositionally distinct compared to fluids of other deposit types. This Special Publication includes an up-to-date summary of thermodynamic parameters of aqueous Au species at high temperatures and pressures; a dataset of fluid inclusion properties and compositions from orogenic deposits of different parts of the world; several comprehensive case studies of different types of gold deposits and their fluids from USA, Brazil, Egypt, Slovakia and Bulgaria; and numerical modelling aimed to define key parameters that affect fluid flow and gold deposition at a range of scales.




Gold Metallogeny and Exploration


Book Description

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 of all major aspects of gold 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.




Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical Studies


Book Description

Economically viable concentrations of mineral resources are uncommon in Earth’s crust. Most ore deposits that were mined in the past or are currently being extracted were found at or near Earth’s surface, often serendipitously. To meet the future demand for mineral resources, exploration success hinges on identifying targets at depth. Achieving this requires accurate and informed models of the Earth's crust that are consistent with all available geological, geochemical and geophysical information, paired with an understanding of how ore-forming systems relate to Earth’s evolving structure. Contributions to this volume address the future resources challenge by (i) applying advanced microscale geochemical detection and characterization methods, (ii) introducing more rigorous 3D Earth models, (iii) exploring critical behaviour and coupled processes, (iv) evaluating the role of geodynamic and tectonic setting and (v) applying 3D structural models to characterize specific ore-forming systems.




Archean Granitoids of India: Windows into Early Earth Tectonics


Book Description

Granitoids form the bulk of the Archean continental crust and preserve key information on early Earth evolution. India hosts five main Archean cratonic blocks (Aravalli, Bundelkhand, Singhbhum, Bastar and Dharwar). This book summarizes the available information on Archean granitoids of Indian cratons. The chapters cover a broad spectrum of themes related to granitoid typology, emplacement mechanism, petrogenesis, phase-equilibria modelling, temporal distribution, tectonic setting, and their roles in fluid evolution, metal delivery and mineralizations. The book presents a broader picture incorporating regional- to craton-scale comparisons, implications for Archean geodynamic processes, and temporal changes thereof. This synthesis work, integrating modern concepts on granite petrology and crustal evolution, offers an irreplaceable body of reference information for any geologist interested in Archaean Indian granitoids.




The Geology of Egypt


Book Description

This richly illustrated book offers a concise overview of the geology of Egypt in the context of the geology of the Arab Region and Northeast Africa. An introductory chapter on history of geological research in Egypt sheds much light on the stages before and after the establishment of Egyptian Geological Survey (the second oldest geological survey worldwide), Hume's book and Said's 1962, 1990 books. The book starts with the Precambrian geology of Egypt, in terms of lithostratigraphy and classifications, structural and tectonic framework, crustal evolution and metamorphic belts. A dedicated chapter discusses the Paleozoic-Mesozoic-Cenozoic tectonics and structural evolution of Egypt. A chapter highlights the Red Sea tectonics and the Gulf of Suez and Gulf of Aqaba Rifts. Subsequent chapters address the Phanerozoic geology from Paleozoic to Quaternary. The Egyptian Impact Crater(s) and Meteorites are dealt with in a separate chapter. The Earth resources in Egypt, including metallic and non-metallic ore deposits, hydrocarbon and water resources, are given much more attention throughout four chapters. The last chapter addresses the seismicity, seismotectonics and neotectonics of Egypt.




Deformation-enhanced Fluid Transport in the Earth's Crust and Mantle


Book Description

30% discount for members of The Mineralogical Society of Britain and Ireland The movement of fluids through rocks has profound consequences for the transport of heat and matter within the Earth. Recently, considerable effort has been expended in determining the mechanisms and pathways of geological fluid flow, with much of this research concentrated on the effects of deformation on rock permeability. Although it is well known that fractures can act as conduits for fluid transport (as evidenced by abundant mineral-fined veins and sheet-like igneous intrusions), the role of ductile deformation has now been recognised as an important factor controlling rock permeability in environments as diverse as the mantle, the deep crust, and shallow crustal shear zones. This book brings together review and research articles united by the theme of deformation-enhanced fluid transport, with the aim of emphasizing the many common roots of this important body of work. Subjects covered include the movement of basaltic melts in the mantle; the segregation, ascent and emplacement of granitic melts in the crust; the flow through the crust of volatile fluids produced during metamorphic events; and the movement of aqueous fluids through fractured rocks near the Earth's surface. Deformation-Enhanced Fluid Transport in the Earth's Crust and Mantle will appeal to all geoscientists interested in the movement of fluids through the Earth. It will prove an invaluable reference work for those working in the field and will provide i useful introduction to this wide-ranging and rapidly evolving area of research for non-specialists.




The Role of Fluids in Crustal Processes


Book Description

Water and other fluids play a vital role in the processes that shape the earth's crust, possibly even influencing earthquakes and volcanism. Fluids affect the movement of chemicals and heat in the crust, and they are the major factor in the formation of hydrothermal ore deposits. Yet, fluids have been overlooked in many geologic investigations. The Role of Fluids in Crustal Processes addresses this lack of attention with a survey of what experts know about the role of fluids in the Earth's crustâ€"and what future research can reveal. The overview discusses factors that affect fluid movement and the coupled equations that represent energy and mass transport processes, chemical reactions, and the relation of fluids to stress distribution.




Antimony


Book Description

Antimony (Sb) is an exciting chemical element ubiquitously present in our daily lives. This book provides a coherent and interdisciplinary picture of our current understanding of this element. Subjects ranging from its mineralogy, mining and environmental chemistry to its potential impact in ecosystems and human health are discussed in this monograph.




Macraes Orogenic Gold Deposit (New Zealand)


Book Description

This book describes the nature and origin of the Macraes gold deposit. It also documents the key features of this spectacular deposit for a wide range of professionals in the resource geology community. This world-class gold deposit has been a spectacular geological and economic success story, as it has developed from a small historical gold mine in discontinuous quartz veins measuring only meters to a large-scale mine in deposits spreading over kilometres in extensive disseminated gold-bearing rock.




Gold metallogeny and exploration


Book Description

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.