Genesis of the Super-large Tungsten, Gold (Antimony) Polymetallic Deposit in Zhaishang, Gansu Province

The super-large tungsten, gold (antimony) polymetallic deposit in zhaishang, Gansu province is located in the western part of the Min-Li metallogenic belt, West Qinling. It belongs to the compound deposit characterized by the multiple stages, multi-source and multi-genesis.The chronological results show that it has experienced two metallogenic stages:the early stage (220Ma) of tungsten mineraliazation and the late stage (140~120Ma) of gold mineralization.The W deposit belongs to the broken alteration rock type of the Cu-W-Mo intermediate-high temperature metallogenic series.The ore-forming material is from hydrothermal fluid, which is closely associated with the magmatism of the w-rich diorite porphyrite(220~210 Ma)in terms of time and space.The Au-forming material mainly derived from the Devonian strata, its mineralization has no direct relation with diorite porphyrite in terms of time and space.The mineralization occurred during the Yanshanian period(140~120Ma), which was in consistent with the Yanshanian tectonic-magmatic activities in West Qinling.The Au deposit belongs to transitional deposit between the carlin deposit and the orogenic deposit, being the Sb-Hg-Pb-Zn intermediate-low metallogenic series.The authors propose that Zhaishang super-large polymetallic deposit is superimposed metallogenic series related to the tectonic-magmatic activities in the mesozoic metallogenic system and has huge prospecting potential.