Origin and evolution of ore fluid, and gold-deposition processes at the giant Taishang gold deposit, Jiaodong Peninsula, eastern China

摘要

The Early Cretaceous Taishang gold deposit is the largest deposit in the Linglong goldfield, Jiaodong Peninsula, with a pre-mining endowment of 326 t of gold. It is hosted in the 165-150 Ma Linglong biotite granite and controlled by the NEE- to NE-trending Potouqing Fault near the northern end of the regional Zhaoping Fault system. Hydrothermal alteration is well developed in the footwall of the Potouqing Fault and is characterized by a narrow zone of sericitization, followed by a wider zone of silicification, and an even wider zone of potassic alteration. The main orebodies (No. I orebody) comprise disseminated and stockwork-veinlet systems, although about 5% of the resources are in larger quartz veins (No. II orebody). Four stages have been identified for both styles of mineralization, on the basis of cross-cutting relationships and mineralogical and textural characteristics: pyrite-quartz-sericite (stage 1), quartz-pyrite (stage 2), quartz-pyrite-base-metal-sulfide (stage 3) and quartz-carbonate (stage 4). Gold was mainly deposited in stages 2 and 3, with minor amounts in stage 1.