Multistage character of gold mineralization at the Nora area (Amur region)

Abstract

The Nora area located in the Dzhagdy-Selemdshinsky metallogenic zone (the eastern part of the Mongol-Okhotsk fold belt) is poorly explored but there is an evident prospect for discov-ering a hard-rock gold deposit. Based on the common Mongol-Okhotsk fold belt strike and the previous exploration results, the recent prospecting works were focused upon revealing ore-bodies of the east-west strike. Analysis of their data has drown the conclusion that there might be at least two stages of gold-bearing mineralization at the explored area. The first one - Au -Ag-As-W stage is typical for deposits in the Dzhagdy -Selemdshinsky zone. It occurs mostly in ore-bodies of the east-west strike. The second – later stage, with the Au-(Ag)-Pb-(Zn) association, has been for the first time detected at this area. It is controlled by latent fractured structures of the north-south strike. Maximum gold concentration is characteristic for ore-bodies with combined development of both stages. Revealed regularities in location of various types gold-bearing mineralization should be taken into consideration for the grid of prospecting works and confirm the high potential of the Nora area.