Structural-Dynamic Factors of Magma and Ore Genesis in the East Sikhote Alin Volcanoplutonic Belt

摘要

The East Sikhote Alin volcanoplutonic belt (ESAB) formed in the Albian-Paleocene. Magmatism and met-allogeny in this belt were related to activation of Sikhote Alin strike-slip faults. Deep NNE-trend-ing 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 structural-dynamic nature and geodynamic settings of Cenoma-nian-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.