Abstract:
The Dangjiang copper polymetallic deposit, located in the northern section of the " Sanjiang metallogenic belt ", is newly discovered in 2014 in Duocai copper polymetallic deposit integrated exploration area in Zhidoi County, southern Qinghai Province.The mineralization age has not been precisely defined, and unified understanding of the genesis of Dangjiang copper polymetallic deposit has not been formed.LA- ICP-MS zircon U-Pb dating shows that the weighted mean age of rhyolite, which is closely related with copper, lead and zinc mineralization, is 227.5±1.7 Ma, in the Late Triassic.Through the comparative study with Galonggema copper polymetallic ore deposit and the analysis of its ore-bearing wall rock, alteration characteristics, ore minerals and ore types, It is believed that the ore-forming process is closely related with volcanic eruption, and the mineralization is formed in the volcanic rhythmical layer of the second rock formation in Batang Group.It is considered that the deposit is formed as volcanic exhalation sedimentation-superimposition reworking type, and the tectonism plays the role of superposition structure for enrichment of ore-forming elements.Comprehensively, we consider that Dangjiang copper polymetallic deposit is formed in the continental margin rift tectonic setting in the northern part of the north Qiangtang block, which provides a new perspective for further studying the tectonic setting of copper polymetallic deposits in the northern" Sanjiang metallogenic belt " and expanding prospecting.