Economic deposits and their tectonic setting / Экономика месторождений и их тектоническое строение

What is economic geology? It may be defined as the study of geological bodies and materials that may be useful to mankind. The materials included are fuels, metallic and non-metallic minerals, rocks and water. This book will exclude considerations of water and building materials, and will concentrate on ores and fuels.

Some people may say that economic geology is a subdiscipline within the geological sciences, but this is not strictly correct, for it is unlike other su}?disciplines, such as palaeontology, igneous petrology, structural geology, and so on, which all go to make up the science of geology, for each of these can exist independently. Economic geology cannot exist as a separate discipline, for it has to be based on the broad spectrum of the geological sciences.

A good economic geologist is also a good geologist, that is a person with a wide background experience of the geological sciences. It must therefore be stressed that no book can serve as a self-contained economic geology text, for to understand economic deposits it is necessary to understand a wide spectrum of geological processes, and this can only be achieved by having a wide background experience in most branches of the geological sciences. Petroleum, coal, evaporite and phosphorite geology require a strong background in sedimentology and structural geology. Ore geology is so extremely varied as to encompass deposits that have been laid down or concentrated by igneous, metamorphic and sedimentary processes, and by circulating magmatic and ground-water hydrothermal fluids, sometimes further concentrated by weathering processes. These cover almost the whole spectrum of the geological sciences. Fundamental also to the study of economic geology is a good background in structural geology, for the foregoing processes are all likely to have been controlled or modified by geological structures. Therefore a suitable background for a practising economic geologist would include igneous petrology, sedimentology, structural geology and, of lesser necessity, metamorphic petrology. Geochemistry is also important because one is dealing with mobilization and concentration of metals and other materials. This would include both organic and inorganic geochemistry to cover the spectrum from fuels to ores. It is clear, therefore, that economic geology is not a branch of, but a culmination of a broad training in, the geological sciences. This book cannot hope to do more than outline the various processes that may have been active in the formation of economic deposits. The necessary background in the various branches of the geological sciences may be obtained from the textbooks detailed in the following references. Structural geology: Dennis (1972), Hobbs, B.E. et al. (1976), Spencer, E.W. (1977); sedimentology: Friedman and Sanders (1978), Reading (1978); igneous petrology: Cox, K.G. et al. (1979), Yoder (1979); metamorphic petrology: Miyashiro (1973), Mason, R. (1978); geochemistry: Krauskopf (1979). Although not necessary for the understanding of the deposits, their discovery and assessment will depend on a variety of techniques, including geophysical methods, exploration geochemistry and eventual drilling. The books detailed in the following references summarize these useful methods: Parasnis (1973), Levinson (1974), Peters (1978), Reedman (1979), Sittig (1980). <...>