The Deposit Characteristics,Post-ore Change And Preservation Of Bajiazi And Erdaogou Gold Deposits In The Jiapigou Gold Belts

The study area(Bajiazi and Erdaogou mining district)is located in the Northeast margin of North China plate and mainly output in the Jiapigou mineral granite-greenstone belt distributed in NW,.Where abundant mineral resources occurred.In this paper,the author attempt to explore the mineralization depth variation through the analazation of the fluid inclusions temperature and pressure data in the deposits in the study area,According to apatite fission track analysis to reveal the uplift history of the ore body and to get the exact denudation data of the ore body.Through the comparison of gold mineralization depth and denudation data,analysing the preservation conditions after the gold deposits formation to provide a theoretical basis for the evalution of the regional gold mineralization and deep ore prospecting.According to the research of the gas-liquid phase inclusion in quartz veins bearing gold with homogenization and cooling method in Erdaogou mining district,the results show that the homogenization temperature of type ? is 310~425.8?,the average temperature is 367.8?,peak temperature is 320~400?,The salinity range is 1.8-9.8%,the peak salinity range is 5.8%-8.2%,the fuild density is 1.8-9.8 g/cm3.The homogenization temperature of type?is 153.2-338.8?,the average temperature is 246?,peak temperature is200-240?,The salinity range is 4.6~11.6%,the peak salinity range is 6.7%-9.2%,the fuild density is 0.54-0.81 g/cm3.The reaserch mothod in Erdaogou and Bajiazi mining district is same,so the results of Bajiazi mining district show that homogenization temperature is 94.7~323?,the average temperature is 202?,the peak temperature is 185-230?,and the freezing temperature is-3.0--18.6?.The salinity is 3.23~18.96%,the average salinity is 11.6%,and the peak salinity is 9%~13%,the fuild density is 0.78~1.02 g/cm3.In general,the ore-forming fluid is a kind of low temperature,low salinity and low-density fluid.The metallogenic pressure of Erdaogou and Bajiazi mining district are 58~120MPa and 26.1~97.4MPa,respectively,and the gold mineralization depths are 2.15km~4.32km and 1.08km~3.42km,respectively.Usually,the deeper of the metallogenic depth,the vertical extension of metallization is bigger,that shows that there is a great potential metallogenic in the study area.Since 130Ma,the denudation of Sandaocha and Sidaocha mining district are very low,the average denudation are 2.74Km and 2.71 Km,respectively,which are less than the metallogenic depths,so the gold deposits are preserved well relatively.In conclusion,the prospect of ore-forming of the study area is great,and the deep has good space for further mineral prospecting.