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地球学报 1987
ON POLYCYCLIC MINEROGENESIS
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Abstract:
In the last twenty years, the investigation on minerogenesis has made rapid progress in China. A train of different points of view from various aspects for the theoretical research on the origion of mineral deposits have been expressed. Basing upon a synthetic analysis of the minerogenetic conditions and distribution of various kinds of mineral deposits of China, and in the light of the concept of the polycyclic tectonic movements, the auther attempts to discuss the problems on polycyclic minerogenesis. Some views on the subjects concerned are also presented.The minerogenetic cycles are related to the cycles of tectonic movements, and thus may be named as tectonominerogenetic cycles. According to the general division of the tectonic cycles of China, the tectono-minerogenetic cycle of China may be correspondingly divided into eleven cycles. With the exception of the oldest one which remains to be supplemented, the others, as arranged in chronological order, are the Fupingian, Wutaian Luliangian, Wulingian Jinningian, Caledonian, Hercynian, Indo-Sinian, Yanshanian and Himalayan tectonominerogenetic cycles (Table 1).The characters of tectonic movements, though differing from place to place, may be basically fall into three categories, viz., those dominated by folding, faulting or oscollating movements. Since these three types of movements may, in general, give rise respectively to metamorphism, magmatism and sedimentation, it is suggested that the minerggenetic process related to each of them may be correspondingly named as folding-metamorphominerogenetic process, faultingmagmato-minerogenetic process and oscillating-sedimento-min-erogenetic process.The polycyclic development of the tectonic movements gives rise to polycyclic development of the minerogenetic processes. The different minero-genetic process cycles in regard to different tectoao-minerogenetic cycles are listed in Table 2. Some details about each process and the general aspect of the distribution of the main mineral resources of China with relation to oscillating-sedimento and faulting-magmato-minerogenetic processes of various tectono-minerogenetic cycles of China are briefly given in the Chinese text and schematically shown in Fig. 1 and Fig. 2.As a consequence of the- crustal development, the composition of the continents has been in general, gradually evolving from ultra-basic to basic-acidic and finally to ultraacidic or alkalic. In conformity with the compositional evolution of the crust, the main mineralized materials have synchronously been evolving from siderophile elements to chalcophile elements and finally to lithophile elements.In the course of minerogenetic evolution, some funda mental characteristics of polycyclic minerogenesis are conspicuous, such as, cyclicity and stage-peculiarity; similarity and differential character; heredity and new-born character; trends of temporal and spatialevolution and serial character) and paragenesis and polygenic character. These my be re