Petrology of hydrothermal metasomatism of intra-ore dolerite dikes of mesothermal gold deposits

Abstract

There is a necessity of working up the geology-genetic theory of hydrothermal gold deposit formation instead of the four hypotheses excepting one another: granitogene, basaltogene, metamorphogene, polygene. The principal aim of the study: substantiation of goldisolating faculty of basaltic magmatism - causing and ensuring ore-forming geologic processes. The methods used in the study: petrologic investigation of the magmatism and accompanying metasomatism fractions by means of empiric observations in gold-ore deposits of the spatially-temporary correlations of magmatic, metasomatic rocks and ore-mineral complexes; minerals diagnostics using electronic microscope in accompaniment of roentgenspectrum analysis; results of total chemical silicate analysis of rocks and balance petro-chemical calculation for estimation of petrogene elements and metals migration in metasomatic processes of the stages ore-forming. The results: the paper proves the formation of gold mineralization in crystalline substratum and black-shale series in final basaltic for mation stage of antidromic granite-diorite-doleritic magmatic complexes, acquiring on account of that status of gold-isolating fluid-ore-magmatic complexes. The first part of the paper introduces the original analytic data on Kedrovskoe deposit (North Trans-Baikal), the second part introduces the data on deposit Zun-Kholba (East Sajan). The second part includes the discussion of the results and conclusions.

Keywords

• mesothermal gold deposits
• petrology
• hydrothermal metasomatism
• intraore dolerite dikes
• hot fluid-conductors