Studies on the fluid inclusions from Lishan gold deposit in Jiapigou, Jilin Province, China

摘要

Lishan gold deposit is a large-scale quartz vein type gold deposit in Jiapigou region.Fluid inclusions in quartz vein type ores taken from No.5 ore vein explain that there are 3 types of primary fluid inclusions i.e. Ⅰ Carbon dioxide, ⅡCarbon dioxide-bearing three-phase, Ⅲ aqueous phase etc. The microthermometric study of fluid inclusions showed that the homogenization temperature of every kind of fluid inclusions ranges from 218.2°C to 420°C; Salinity ranges from 3.1wt%NaCl equiv, to 11.4 wt%NaCl equiv. The intergrowth of type Ⅰ, Ⅱ and Ⅲ fluid inclusion,combined with analysis of composition of Carbon dioxide phase of fluid inclusions reflect that it is immiscible NaCl-H2O-CO2 system. According to the temperature-pressure estimation method in immiscible systems, we calculated the metallogenic temperature is 335-415 °C and metallogenic pressure is 750-1250×105 Pa, indicating to formed in a depth of 4.4-7.5 km.