Abstract：Chenlou fluorite deposit is the largest deposit of western Henan province. It is located in F3 fault structure of Taishanmiao rock in late Yanshan and its ore body is strictly controlled by the F3 fault structure.According to the relations between vein cutting and mineral metasomatism, the hydrothermal mineralization period of deposit can be divided into four stages, including quartz vein stage ( Ⅰ) , early fluorite mineralization stage ( Ⅱ) , late fluorite mineralization stage ( main metallogenic stage) ( Ⅲ) and Carbonation stage ( Ⅳ) . In the main ore body M3-Ⅰ, the early quartz vein stage is mainly composed of CO2-type inclusions, and the main fluorite mineralization stage of fluorite has mainly developed gas-liquid two-phase inclusions ( i. e. H2 O-NaCl system) . From the quartz vein stage to main metallogenic stage, the average homogenization temperature ranges299. 9 ℃, 235. 6 ℃ and 187. 7 ℃. The average salinity ranges 6. 14%, 0. 71% and 0. 67% NaCl eqv., and the average fluid density ranges 0. 86 g/cm3, 0. 81 g/cm3 and 0. 81 g/cm3. The ore-forming fluids are generally characterized by shallow formation, medium-low temperature, low-salt, low-density and CO2-depleted. They evolved from medium temperature and low salinity to low temperature and lower salinity. The range of temperature, salinity, and density was also significantly narrowed mainly because of continuous addition of atmospheric precipitation during mineralization. The metallogenic depth of main metallogenic stage is estimated ranging0. 73 ～ 2. 00 km with an average of 1. 17 km based on the ore-forming pressure. The deposit has the characteristics of a medium-low temperature metagenesis sub-volcanic hydrothermal fluorite deposit.

Keyword：fluid inclusion;geological significance;Chenlou fluorite deposit;Songxian county, Henan Province;