О геохимической зональности Верхне-Алиинского месторождения золота в Забайкалье (Россия)

Abstract

The relevance of the study lies in the need to have objective geochemical data to assess the erosion section level of newly discovered manifestations of ore deposits. One of the examples, used to solve this problem, is the results of the mineralogy and geochemistry study of the Verkhnealiinsky gold deposit in Transbaikalia. The purpose of the study is to determine the zonality in the distribution of minerals, gold and associated chemical elements in the deposit space and to evaluate them as criteria for ore zoning. The object of the study is the Verkhnealinsky gold deposit. The subject of the research is the spatial distribution of minerals and chemical elements in the gold ore zones of the deposit. The methodology consists in diagnostics, determination of the chemical elements content and the establishment of regularities in their spatial distribution using modern methods of analysis, namely, electron microscopy, assay analysis and ICP MS, determination of the degree of the crystal structure perfection. The results of the study are as follows: the content of gold and associated chemical elements in the three most industrially important ore-bearing zones of the Western, Latitudinal and Eastern zones, which differ in the depth of formation, have been determined. The least deep Eastern zone is characterized by the intensive development of zinc, lead, antimony, and arsenic minerals and, accordingly, their maximum content in its upper part. For the deepest Western zone, the maximum development of pyrrhotite, chalcopyrite, and cobalt has been revealed, and it is shown that the cobalt-nickel ratio is an important criterion for assessing the level of erosion cut. An important criterion of depth is also the degree of the crystalline structure perfection of vein quartz, which depends both on the crystallization rate, which is determined by the depth from the day surface during the formation of the deposit, and on the amount of isomorphic impurities in it. It is also shown that one of the important criteria for the level of erosion section is the content of rubidium in veined quartz and arsenic in pyrite.