Известия Томского политехнического университета: Инжиниринг георесурсов (Jun 2018)
Ore geology problems and the human factor. Part 2. Magmatism and mesothermal ore-formation
Abstract
The relevance of the research. The coexistence of the granitic, basaltic, metamorphic, polygenetic hypotheses of one and the same hydrothermal deposits of gold, coloured metals (Sn, W, Mo, Cu, Pb, Zn, Ni, Co) formation stimulates investigations directed on correction, deepening hydrothermal ore-formation theory and improving, development of the forecast-search criteria of the deposits, necessary for the search of new subjects and replenishment of the metals mineral products base. The main aim of the research is to assess metalliferous ore-forming solutions sources studying the consistency, content, material expression of mesothermal gold deposits formation geologic processes of the south mountain-folded frame of Siberian craton. The methods: study of the formation consistency, mineral-chemical compositions of accompanying granitoid plutons, massifs, ultra-metamorphic hearth-dome structures dikes of the magmatic rocks, their spatial-time correlations and their relation to ore-mineral complexes, complete chemical (wet) silicate analysis of rocks, roentgen-spectral analysis of chemical compositions of minerals, analysis of the isotope compositions of the sulphide sulphur and carbonaceous carbon of ores and near-ore metasomatites, petro-chemical calculations. The results of the research. The paper introduces the proofs of generation of the forming mesothermal gold deposits metal-bearing solutions into mantle chambers of the basic melts - the facts of the simultaneous functioning the latters and ore-forming fluids into crust after crystallization of the granitic melts, data about fluid-conducting in hot condition function of the inside-ore dolerite dikes - along with fractures in the routes of metal-bearing solutions rising from the chambers of the generation into forming deposits, the facts of inheritance by the near+ore metasomatites (beresites) of petro-chemical type inside-dike metasomatism (supply K, S, CO2, subtraction Na, Si), contrasting anomalies into inside-dike and near-ore metasomatites of femic elements (P, Ti, Ca, Mg, Fe, Mn), isotope relations of the sulphide sulphur and carbonaceous carbon relative to mantle marks. The paper discusses negative influence of the human factor on problem solution which consists in priority of the theoretic ideas about generation of metalliferous solutions into crustal chambers of granitic magma - suggested by authority instruction idea though it does not correlate with those observed in deposits facts, which are not congruent with theoretic ideas and therefore they are not attracted for estimating the idea viability. Meanwhile the fact of simultaneous functioning of basic melts in mantle and forming mesothermal deposits of coloured metals solutions in crust after crystallization of granitic melts is proved by existence of aftergranitic till-ore, inside-ore basic dikes - transmitters of information about metalliferous solutions sources. This fact testifies about formation of mesothermal deposits of colour metals and gold on one script, there+ fore it is recommended to decide the problem of dependence of mesothermal ore-formation by magmatism in coloured metals depo+ sits according to the programme of the research described in this article.
