Mineralogical study and significance of the basalt-hosted Carlin-type Au deposits in southwestern Guizhou Province,China  

作　　者：Yuhong Yang Shen Liu Jianzhong Liu Zepeng Wang Bingqiang Zhang Chengfu Yang 

机构地区：[1]State Key Laboratory of Continental Dynamics,Northwest University,Xi’an 710069,China [2]Bureau of Land and Mineral Resources Reserve of Guizhou,Guiyang 550000,China [3]Innovation Center Ore Resources Exploration Technology in the Region of Bedrock,Ministry of Natural Resources of the People’s Republic of China,Guiyang 550018,China [4]Guizhou Bureau of Geology and Mineral Exploration and Development,Guiyang 550004,China [5]College of Resource and Environmental Engineering,Guizhou University,Guiyang 550025,China [6]Geological Party 105 of the Guizhou Bureau of Geology and Mineral Exploration and Development,Guiyang,China

出　　处：《Acta Geochimica》2024年第6期1241-1254,共14页地球化学学报（英文）

基　　金：funded by the Talent Team Program of Science and Technology Foundation of Guizhou Province(CXTD[2021]007);the Key Project of Natural Science Basic Research Program of Shannxi Province(2023-JC-ZD-16);the National Natural Science Fund of China(U1812402);the National Natural Science Fund of China(41962008);the National Key Research and Development Program of China“Exploration and Exploitation of Deep Earth Resources”(2017YFC0601500);the Guizhou Province Graduate Research Fund(YJSCXJH[2020]095);the public welfare and fundamental project Fund of Guizhou Province(520000214 TLCOG7DGTNRG)。

摘　　要：The Jiadi and Damaidi gold deposits in southwest Guizhou Province are the largest basalt-hosted Carlintype gold deposits recently discovered in China.This study uses the Tescan Integrated Mineral Analyzer,supported by detailed field investigations,regional geological data,and extensive sample collections,including mineralized ore,altered wall rock,and unaltered basalt samples,for orebearing and geochemical analyses.Comparative analysis between altered and unaltered basalt samples revealed a mineral assemblage of sericite,quartz,and pyrite.This mineral composition forms through the hydrothermal alteration of unaltered basalt,originally containing feldspar,pyroxene,and ilmenite.The wall rock primarily features sericite,quartz,and hematite.During the alteration process,major,trace,and rare earth elements notably migrate.In the Jiadi deposit,K_(2)O,Rb,Au,and REE significantly increase,while Na_(2)O,CaO,MgO,and MnO decrease.SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)levels remain relatively stable.In the Damaidi deposit,K_(2)O,Rb,and Au enrich,contrasting with the depletion of Na_(2)O,CaO,MgO,and MnO,while SiO_(2),Fe_(2)O_(3),Al_(2)O_(3),TiO_(2),and REE show no significant changes.In the wall rock,TiO_(2),Al_(2)O_(3),K_(2)O,and REE increase,while Na_(2)O,CaO,MgO,and MnO decrease;SiO_(2)and Fe_(2)O_(3)content remains unchanged.The mineralization process likely originated from mid-to low-temperature,reductive magmatic hydrothermal fluids rich in CO_(2),CH_(4),N_(2),H^(+),S^(2-),HS^(-),H_(3)AsO_(3),and[Au(HS_(2)]^(-).These fluids migrated to tectonically weak zones in the Lianhuashan area,where Emeishan basalts are present.They reacted with Fe-bearing minerals in the basalt,such as ferro-hornblende and ilmenite,forming pyrite,arsenic-bearing pyrite,and arsenopyrite,thus enriching Au in these minerals.Additionally,K^(+)and H^(+)in the fluid reacted with plagioclase in the basalt,forming sericite and quartz.As the fluid entered the wall rock from structural weak zones,its oxidation increased,leading to the complete or partial reac

关 键 词：BASALTIC Ore-bearing rocks CARLIN-TYPE Au deposit Mineralogy Mineral assemblage Element migration 

分 类 号：P618.51[天文地球—矿床学]