P 51 Petrological model of formation of giant ore deposits [Text] / A. A. Marakushev, N. A. Paneyakh, V. L. Rusinov, N. N. Pertsev, I. A. Zotov // Geology of Ore Deposits. - 1998. - Vol. 40, № 3. - P211-227. - Bibliogr. : p. 227 (46 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): PETROLOGICAL MODEL -- MODELLING -- ORE -- ORE DEPOSITS Аннотация: The available data on the giant ore deposits of chromium (Kempirsai in the Urals), platinum-group metals (Bushveld in Africa), platinum-bearing copper-nickel ores (Talnakh in the Noril'sk district, northern part of the Siberian Platform), zinc-copper (massive sulfide) ores (Gai, Sibai, and Uchaly) and apatite deposits (Khibiny, the Kola Peninsula) is summarized. The giant sizes of the deposits are caused by extraordinary ore-forming processes directly associated with the highly extensive petrogenetic processes. These processes resulted in the formation of peculiar dunites in the hyperbasite complexes (chromite ores), agpaitic urtites in alkaline associations (apatite deposits), development of low-sulfide horizons and hortonolite dunites in the basite-hyperbasite layered intrusions (platinum-group metal deposits), specific processes of transmagmatic sulfurization of the iron-rich igneous differentiates (Cu-Ni sulfide and massif sulfide ores), and processes of magmatic replacement of hyperbasites that cause the alkaline agpaitic affinity of magmatism. This agpaitic tendency increases the solubility of carbon-bearing fluid components (CO2, CH4, etc.) in magma and leads to the concentration of ore metals, which form chloride-carbonate and hydrocarbon migrating compounds in the transmagmatic fluids. Some mineralogical-petrological prospecting criteria are deduced on the basis of genetic models of giant ore deposits. |