Study on Geological Characteristics and Fluid Inclusion of Jiagongtai Gold Deposit in Gansu

Jiagongtai gold deposit is one of the most representative gold deposits in the south of Danghenanshan Mountain,Qinling-Qilian-Kunlun orogenic system.In order to find out the genetic type of Jiagongtai gold deposit,the geological characteristics were studied,and microthermometry and Laser Raman analysis of fluid inclusions in quartz of metallogenic stages were explained.The results show that the gold deposit locates at the intersection of NW-structure and NE-structure,mineralization occurs in the granite and epimetamorphic marine clastic rocks of Lower Ordovician upper group and is strictly controlled by the NW-structure;most of the ore bodies are vein or lens-like with high grade of Au(1.98×10-6),accompanying Ag and a small amount of harmful components;fluid inclusions in quartz of metallogenic stage have mainly two types,including gas-liquid two-phase and a little of gas-rich phase;the ore-forming fluid is NaCl-H2O system with low salinity and low CO2,the metallogenic temperatures(236 ℃-245 ℃)are middle,