Geochemistry and Genesis of Igneous Rocks in Jiadanggen Porphyry Cu(Mo) Deposit, Qinghai Province,China

The Jiadanggen porphyry Cu(Mo) deposit lies in the east of Qimantage-Dulan suborogen, East Kunlun orogen,Qinghai Province.It is a newly discovered mineral deposit in recent years,and with low degree in studying. The geochemistry analysis on igneous rock samples inthe Jiadanggen mining area shows that the ore bearing porphyry are characterized by high SiO₂,alkali,low TiO₂,CaO,and MgO,which is high-potassium calc-alkaline series.The REE are characterized by LREE enrichment,with obvious negative Eu anomalies. The trace elements are characterized by K,Rb,Ba,etc enrichment obviously; Ta,Nb,Zr,Hf,etc enrichment relatively; P,Ti,Y,Yb,etc depletion obviously. The characteristics of the REE and trace elements indicated the continental margin arc tectonic setting. Combining regional geology background and geochemistry of the igneous rocks in Jiadanggen deposit,the Jiadanggen igneous rocks may be formed in the early stage of the collision orogeny,continental margin arc and collision orogeny coexistence environment. And it was formed from dehydration of residual oceanic crust which caused mantle wedge partial melting.