Characteristics And Model For Shuiyindong Gold Deposit In Southwestern Guizhou, China

The southwestern Guizhou Province is the most important metallogenic province of Carlin-type gold deposits in China. There are two kinds of Carlin-type gold deposits: fault-controlled and stratabound. The fault-controlled Carlin-type gold deposits are localized at the compressive shear faults and hosted in siltstones and silty mudstones of Middle or Lower Triassic. The stratabound Carlin-type gold deposits are controlled by anticlines and hosted in silty bioclastic limstones of Upper Permian. There are lots of studies on fault-controlled gold deposits, but a few on stratabound deposits. Recently, the new findings of some large scale stratabound gold deposits with high grade orebodies and ores make stratabound gold deposits as an important and characteristic kind of Carlin-type gold deposits in the area. The Shuiyindong gold deposit, the most important stratabound Carlin-type gold deposit, has been studied systematically, and the major understandings on its characteristics and model for it are as follows:1. The gold deposit is controlled by both the structure and favorable lithology. It was located nearby the core of the Huijiabao anticline and orebodies are hosted in thelimestone within the sedimentary series of clayrock--limestone--clayrock. Most oforebodies are stratiform ones. However, some orebodies with less importance are controlled by low angle faults and called as fault-controlled orebodies.2. The gold mineralization occurred under low-temperature with Th of 220℃±.Common hydrothermal alteration types such as silicification, dolomitization, and pyritization have been observed. The gold deposit has characteristic elemental assemblages of Au-As-Hg-T1. Gold mainly presents as native gold, as liny inclusions in As-rich pyrite rims on earlier stage pyrites and arsenopyrites. The As-rich pyritesand arsenopyrites are also very small (about several tens of μ m), which indicates...