The Geochemical Features of Ores and Host Rocks of the Malo-Taryn Orogenic Gold Deposit (Verkhoyansk–Kolyma Folded Area, Northeast Russia)

Abstract

This paper presents the results of a study of the distribution of major, trace, and rare-earth elements in the terrigenous rocks, wall-rock metasomatites, and ore zones of the orogenic Malo-Taryn gold deposit (Verkhoyansk-Kolyma folded area , Northeast Russia). An important role in the formation of metasomatites and ore zones was played by hydromicatization, carbonatization, sulfidization, and silicification, which caused the different mobility of major elements and the predominant development of acidic low-temperature carbonic–calcium metasomatism. An increase in the quartz content in the wall-rock metasomatites and ore zones was accompanied by the removal of most rock-forming elements (K, Na, Al, Fe, Mg, and Тi) and input of Ca and CO2. The ores and metasomatites of the deposit are characterized by the As–Au–Sb–W geochemical specialization at low Bi, Co, Ni, Cr, Cu, and Zn and high Li, Ag, Cd, and Sc concentrations. Their REE distribution patterns in modified rocks are similar to those of the Upper Triassic host rocks, with some tendency to a decreasing REE total content. It was established that REE are removed during the formation of metasomatites and ores. The values of the Eu/Eu* (0.61–0.88) and Ce/Ce* (0.6–1.3) anomalies indicate slightly reducing conditions of ore formation with a limited involvement of oxidized meteoric water.