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.
Precious metals continue to have economic and sociocultural importance, as their usage evolves and diversifies over time. Today, the industrial application of precious metals is increasing with the development of scientific and technological innovations. Especially, the biological cycling of these metals is receiving more and more attention, as the microbiota may be key to a range of issues regarding exploration, ore-processing and metallurgy, and the processing of electron waste. In this volume, we focus on enhancing the fundamental understanding of the biological processes that drive noble metal cycling and examine how this knowledge may be turned into biotechnolical applications.
Gold occurs in many settings, but the dynamic nature of Earth’s crust means overlapping and overprinting deposit styles are common. Characterization of mineralization from an early stage becomes important, particularly where the mineralization is complex, in order to maximize exploration and project development success and mining productivity. Various techniques are used at different stages of a project to characterize gold deposits. This Special Publication offers a cross-section of some specific techniques used to investigate a variety of gold deposit types. The papers highlight both the breadth of the available techniques and their utility in deposit characterization, but also the many significant remaining questions and problems related to the exploration and research of gold deposits. Several papers include suggestions of avenues for fruitful further research, including a paper discussing a new approach to classifying orogenic gold deposits, and a paper describing archaeological applications of natural gold analyses.
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.
This book addresses the origin of gold deposits to answer questions of science and curiosity. These answers contribute in turn to the improved exploration and mining of gold. Initially there is a summary of the methods used to address the genesis of gold deposits including some of the essential science and concepts. Five basic observations follow that apply to many gold deposits and need to be considered in any genetic ideas. Magmatic processes enriching gold are discussed followed by the role of aqueous fluids during gold deposit formation at elevated temperatures and pressures. Modifying effects after deposit formation include high-grade metamorphism, retrogression, weathering, and erosion. The main types of gold deposits are then explained within the spectrum of viable genetic ideas, with informal names for these examples that include gold-only, gold-plus, Carlin, slate-belt, epithermal, porphyry, iron oxide copper gold, and Archean greenstone. Case histories are included in which the role of gold geology contributed directly to discoveries—one example is at the province-scale and another at the goldfield-scale. Unlike other books on the subject, this one addresses virtually all gold deposit types rather than focusing on one type in isolation. The primary readership includes industry geologists, senior undergraduates, postgraduates, and those with some knowledge of science and an interest in the gold industry.
Ore deposits form by a variety of natural processes that concentrate elements into a volume that can be economically mined. Their type, character and abundance reflect the environment in which they formed and thus they preserve key evidence for the evolution of magmatic and tectonic processes, the state of the atmosphere and hydrosphere, and the evolution of life over geological time. This volume presents 13 papers on topical subjects in ore deposit research viewed in the context of Earth evolution. These diverse, yet interlinked, papers cover topics including: controls on the temporal and spatial distribution of ore deposits; the sources of fluid, gold and other components of orogenic gold deposits; the degree of oxygenation in the Neoproterozoic ocean; bacterial immobilization of gold in the semi-arid near-surface environment; and mineral resources for the future, including issues of resource estimation, sustainability of supply and the criticality of certain elements to society.
A comprehensive guide to carbon inside Earth - its quantities, movements, forms, origins, changes over time and impact on planetary processes. This title is also available as Open Access on Cambridge Core.
Environmental Mineralogy and Bio-Geochemistry of Arsenic provides a comprehensive understanding of arsenic geochemistry in the near-surface environment. Topics covered include the mineralogy, thermodynamics, geochemistry, analysis, microbiology, and bioavailability of arsenic, with emphasis on implications for arsenic toxicity, geochemistry in natural ground waters, and mine-associated impacts and possible mitigation options. This volume is useful for those seeking to understand arsenic geochemistry and biological interactions in the near-surface environment, Clay Minerals does not use an online manuscript tracking/submission system. as well those working for mining companies, the chemicals industry, NGO’s or government bodies concerned with reducing the impact of arsenic on the environment.
