Revaluation of 'old' ore mining areas of the Amur River region (Russia)

摘要

In recent years, highly liquid precious metals have been mined in the Russian Far East. The state fund has no facilities with confirmed reserves. However, there is a real possibility of reviving the 'old' mining areas. Based on the Lower Amur region (Khabarovsk region) the prospects of gold reserves accumulation using 'small' fields (in 50-80-s conception) are considered. It deems new to determine the potential of these facilities from the viewpoint of large-scale mineralization and to involve the territory under consideration in the assessment of the gold-bearing manifestations. 'Reference' deposits were selected and their specific productivity was assessed, which was extended to similar by properties manifestations. Within the Lower Amur region, geological investigations revealed about 300 small deposits and mineral occurrences. 34 objects localized at the clusters of submeridional and sublatitudinal faults intersection, were identified as promising. Basically, the gold-ore blocks were compared with the 'standards': Belogorsky (near-surface), Dyappe (subvolcanic) and Zimovye (hypabyssal). The determining factors were the structural features of mineralization localization, facies conditions, the ores composition and metasomatites, the zonality of ore-metasomatic formations, the erosion of objects and the completeness of hydrothermal processes. The author's assessment is confirmed by the results of exploration works at 15 'small' deposits and ore occurrences, with the transfer of 11 of them to the category of large and medium-sized.