Primary halos of liquation-type magmatic deposits proper
Abstract
The liquation type of magmatic deposits proper includes commercial accumulations of disseminated sulfide copper-nickel ores, which occur in rocks of basic-ultrabasic composition (norites, gabbro-norites, olivine diabases, pyroxenites, peridotites). According to modern ideas, the formation of liquation-type deposits occurs by separation of magma into immiscible liquids - silicate and sulfide even before the onset of crystallization. The isolated sulfide secretions merge into droplets and under the influence of high specific gravity sink to the bottom parts of intrusions, where they form accumulations. Deposits of liquation disseminated ores are syngenetic with the host rocks. Consequently, the primary halos of these deposits are also syngenetic. The degree of study of the conditions of formation of deposits of this genetic type is clearly insufficient, so the following ideas about the occurrence of halos of syngenetic disseminated ores and the interpretation of these halos can be satisfactory only insofar as they correspond to the accepted liquation-magmatic hypothesis of formation of the ores themselves.
References
- Bowen N. L. The Evolution of Extrusive Rocks. Transl. from English, ed. by V. V. Luchitsky, ONTI NKTP USSR, 1934.
- Bowen N. L., Tuttle O. F. The MgO-Si02-N20 System. Coll. Problems of physico-chemistry in mineralogy and petrography. IL, 1950.
- Volkov I. D. On the methodology of geochemical sampling of gabbro-dolerite intrusions in the Norilsk district. Scientific Records of NIIGA, vol. 3, 1964.
- Godlevsky M. N. To the question about the genesis of sulfide copper-nickel deposits on the Siberian platform. Geology of Ore Deposits, No. 2, 1959.
- Gorbunov G. I. Mineralogical and geochemical features of sulfide copper-nickel ores of Pechenga. Coll. Materials on Mineralogy of the Kola Peninsula, vol. IV. Nauka, 1965.
- Zontov N. S. Laws of differentiation of copper-nickel sulfide melts. Soviet Geology, No. 6, 1958.
- Coates R. Primary banding in basic deep rocks. Translations in geology and minerals. № 85, 86. Centr. Geol. Lib. l., 1937.
- Kreuth G. R. Colloids. Goskhimtekhizdat, 1933.
- Ovchinnikov L. N. Some problems of magmatic ore formation. Proc. AS USSR, Ser. of Geology, No. 4, 1959.
- Polkanov A. N. Gravitational fractionation of solid phase and crystallization differentiation. In the book: Problems of Petrography and Mineralogy, Part I. PH of the AS USSR, 1953.
- Safronov N. I. Fundamentals of geochemical methods of ore deposits prospecting. Methodical manual. Pt. II. PH VITR, L., 1963.
- Turner F., Verhugen D. Petrology of eruptive and metamorphic rocks. IL, 1961.
- Barlow A. E. Econ. Geol., No. 1, 1946.
- Hawley J. Е. Canad. Mineralogist, v. 7, No. 1, 1962.
- Stonehouse H. Amer. Mineralogist, v. 39, № 5-6, 1954.