Distribution of Mineralization, Ages, and Sources of the Malomyr Gold Deposit, Eastern Part of the Mongol–Okhotsk Fold Belt

Abstract

A reliable estimate is obtained for the gold mineralization age for the Malomyr deposit (eastern part of the Mongol–Okhotsk Fold Belt), one of the most well-known in the Russian Far East. The obtained data indicate that the age of the hydrothermal ore process that led to the formation of the Malomyr deposit can be estimated at ~134–130 Ma and the age of postore dikes is 110–104 Ma. At the same time, there are no data on magmatism manifesting itself within the studied region 134–130 Ma ago, making impossible to link the ore mineralization of the Malomyr deposit to magmatic processes. We think that dislocation processes accompanied by hydrothermal activity played a significant role in the mobilization, redistribution, and formation of the Malomyr deposit, which was supported by the results of structural studies. The first results of Rb-Sr and δ³⁴S studies indicate that the ore material came from both crustal and mantle sources.