DEEP-SEATED STRUCTURE OF THE LOWER AMUR PROVINCE AND EPITHERMAL GOLD MINERALIZATION THEREIN

Abstract

The density and magnetic models of the Earth’s crust and lithospheric mantle were developed for the Lower Amur River gold-bearing area. Geological and geodynamical interpretations were made of the deep-seated inhomogeneities found there. It has been shown that the main differentiation of regional geophysical fields in the area is related to the subcrustal mantle inhomogeneities and magmatic bodies in the middle and upper crusts. These inhomogeneities resulted from the Late Cretaceous – Cenozoic magmatic processes occurring in this segment of the Paleoasian margin under subduction conditions, in the mode of strike-slip margin or continental rifting.The spatial relationship was shown between the epithermal gold deposits and some of the deep-seated structural features of the area. Consideration was given to the role of the mantle density boundaries and up to 20 km deep density inhomogeneities in the gold mineralization distribution. There were identified zones of development of deep-seated magmatic bodies which can be interpreted as basaltic intrusions tracing the inferred deep-seated magma-controlling faults, to which, in its turn, gold mineralization can be related.