Fluid Inclusion Studies and the Genesis of the Kugadri Gold Deposit, Kazakhstan

The Kugadri gold deposit is located in the Chuhe-Kendektas gold, lead, zinc, copper and molybdenum metallogenic subzone of the Chuhe-Kendektas gold, lead, zinc, copper and molybdenum metallogenic subzone of the Chuyili-Tianshan metallogenic province in Kazakhstan. The geotectonic location belongs to the Muyunkumu-Kezirkumu-Ili microplate of the Kazakhstan-Junggar plate in the Central Asian orogenic belt. The Kugadri gold deposit is one of the important large deposits in this area. The study of the ore-forming fluid of the deposit has important guiding significance for deepening the understanding of the genesis of the deposit, the study of the regional metallogenic regularity and the prospecting and exploration work. Based on the geological survey of the mining area and the study of the geological characteristics of the deposit, this paper carried out the petrography, microthermometry and laser Raman analysis of ore-bearing quartz vein fluid inclusions in the metallogenic stage. The results show that there are three types of fluid inclusions in Kugadri gold deposit: C, W and S; the complete homogenization temperature of C-type inclusions is 278～421 ℃, and the salinity is 0～13.9 wt% NaCleqv. The complete homogenization temperature of W-type inclusions is 119～378 ℃, and the salinity is 1.1～22.9 wt% NaCleqv. The complete homogenization temperature of S-type inclusions is 136～327℃, and the salinity is 29.1～31.0 wt% NaCleqv. The estimation of metallogenic pressure and depth shows that the metallogenic pressure is 95～200 MPa, the metallogenic depth is about 2～5 km, and the metallogenic temperature is 290～380 ℃. Combined with the geological characteristics of the deposit, it is considered that the ore-forming fluid of the Kugadri gold deposit has the characteristics of CO₂-rich, medium-low salinity metamorphic fluid, and the genesis of the deposit is orogenic gold deposit.