Contrastive Study on Features of Ore-forming Rock Mass between Area A Porphyry Type and Area B Skarn Type in Ka'erqueka Copper Molybdenum Deposit in Qinghai Province

Ka'erqueka Cu deposit in Qinghai province has porphyry-skarn-hydrothermal metallogenic characteristics of the series. The orefield is divided into three areas as A, B and C, among which area A is mainly porphyry mineralization, area B is mineralization of skarn type. Copper polymetallic deposit primarily originated in the contact area between granodiorite and porphyritic monzonitic granite and Cambrian-Ordovician Tanjianshan Group, that is skarn ore belt and porphyry copper deposit. By comparison of mineral assemblage and petrological geochemical characteristics, the porphyritic monzonitic granite of Area B in Ka'erqueka deposit is a product of the early stage of Caledonian subduction collision. Both porphyry mineralization in porphyritic monzonitic granite of Area A and skarn mineralization in granodiorite of Area B are products of subduction collision orogenic stage in late Triassic Indo-Chinese epoch, that produced a typical porphyry deposit system, then superimposed on early mineralization in Caledonian period, and finally the larger copper molybdenum deposit was formed.