This book is intended primarily for exploration geologists and post graduate students attending specialist courses in mineral exploration. Exploration geologists are engaged not only in the search for new mineral deposits, but also in the extension and re-assessment of existing ones. To succeed in these tasks, the exploration geologist is required to be a "generalist" of the Earth sciences rather than a specialist. The exploration geologist needs to be familiar with most aspects of the geology of ore deposits, and detailed knowledge as well as experience play an all important role in the successful exploration for mineral commodities. In order to achieve this, it is essential that the exploration geologist be up to date with the latest developments in the evolution of concepts and ideas in the Earth sciences. This is no easy task, as thousands of publications appear every year in an ever increasing number of journals, periodicals and books. For this reason it is also difficult, at times, to locate appropriate references on a particular mineral deposit type, although this problem is alleviated by the existence of large bibliographic data bases of geological records, abstracts and papers on computers. During my teaching to explorationists and, indeed, during my years of work as an explorationist, the necessity of having a text dealing with the fundamental aspects of hydrothermal mineral deposits has always been compelling. Metallic mineral deposits can be categorised into three great families, namely: (I) magmatic; (2) sedimentary and residual; (3) hydrothermal.

Includes detailed and technical discussions of deposits in Canada, Zimbabwe, South Africa, Australia, Chile, United States, Japan, and Czechoslovakia.

This Special Issue covers a broad range of topics related to the mineralogy of noble metals (Au, Ag, Pt, Pd, Rh, and Ru) and the occurrence, formation, and distribution of these elements in natural ore-forming systems. This collection of eleven research articles discusses various problems related to these topics. I hope this Special Issue will contribute to a better understanding of the genesis of gold, silver, and other noble metal deposits as well as the behavior of these elements in endogenic and supergene environments, and suggest ways forward to solving the problem of their full extraction from ores.

PERTH Western Australia March 2000 Increasingly explorationists are seeking to find new ore deposits in poorly prospected areas, be they geographically remote, such as in the Arctic, or geologically remote, such as those under sedimentary cover. Modern prospecting techniques, including low-detection-level geochemistry and the use of advanced geophysical instrumentation have greatly assisted explorers but fundamental to any soundly based exploration program remains an understanding of the geological framework of ore deposits. This allows the development of deposit models on macroscopic and mesoscopic scales. This book by Dr. Franeo Pirajno draws on his extensive and wide global experience. To set the scene for a discussion of ore deposit generation Franeo details the Earths internal structures and mantle dynamics. He then explores the impact of mantle plumes on the crust and in particular their role in the production of magmatic environments, and in continental scale rifting. This includes a descriptive section on magmatic provinces around the globe, which highlights the importance of plumes. Any study of Earth processes needs to take into account the effects of extraterrestrial bombardment, and in particular the results from the impacts of large bolides. The effects of these impacts on the atmosphere and on life have now been recognised as profound. It is likely that the effect ofthese impacts on the Earth's crust is as equally profound.