The discovery of a large-size fine disseminated gold deposit in eastern Qinghai

Located in Tongde County of eastern Qinghai, the Jiawu gold deposit is another large-size gold deposit discovered by Gold Prospecting Armed Police in recent years. The ore deposit is situated between western Qinling and eastern Kunlun. Ore bodies occur in Middle-Lower Triassic strata, and are horizontally in the gentle wave form and vertically in the veinlike or layered form. The main metallic minerals include pyrite and arsenopyrite, and gold is disseminated in fissures of quartz and intergranule space between arsenopyrite and pyrite in the microgranular form. The high organic-C content suggests that the ore bodies are obviously controlled by the regional fracture belt and lie in NW-and EW-trending structural alteration zones. Due to its high Au and organic-C content, the slate in Middle-Lower Triassic Longwuhe Group is considered to be the favorable host rock. Ore bodies are spatially accompanied by Indo-China medium-acid magmatic rock. A preliminary study reveals that this deposit is a kind of fine disseminated gold deposit directly controlled by the structural alteration zone and has a genetic relationship with sedimentation and magnetic activity. Until now, the proven reserves of the total 22 ore bodies have reached over 20 tons.