STRUCTURAL-DYNAMIC FACTORS OF MAGMA AND ORE GENESIS IN THE EAST SIKHOTE ALIN VOLCANOPLUTONIC BELT

Abstract

The East Sikhote Alin volcanoplutonic belt (ESAB) formed in the Albian–Paleocene. Magmatism and metallogeny in this belt were related to activation of Sikhote Alin strike-slip faults [4, 7]. Deep NNE-trending strike-slip zones control tin, tungsten, base metal, and gold deposits. At the same time, areas of dispersed ore mineralization up to 10 km wide are observed between these strike-slip zones. Their structuraldynamic nature and geodynamic settings of Cenomanian–Cenozoic magmatism, which produced the volcanic cover of the belt, remain unclear thus far. We investigated this issue in the Samarga ore district, which represents a large ESAB fragment located in the northeastern Primorye region. We also analyzed results of structural investigations conducted during additional geological investigation of the region by the Primorye prospecting–mapping expedition. It is established that NW-trending zones of ore mineralization are controlled by extension structures of the continental crust related to strike-slip faults that served as the main magma conduits during the formation of the ESAB volcanic cover in the Cenomanian–Paleocene.