摘要
通过矿床地质、矿物包裹体及向位素地球化学研究确定庞西洞银矿受韧性-脆性剪切构造带控制,成矿与燕山期同熔型花岗岩有关。矿床围岩蚀变钾化、黄铁绢英岩化强烈。成矿流体K^+>Ca^(2+)>Na^+>Mg^(2+);SO_4^(2-)>Cl->HCO_3->F-;CO>>CO_2>CH_4。流体低盐度(2.2wt％～4wt％NaCI)、弱酸性(pn为4.6)、密度0.81。成矿温度270℃,压力700×10~5Pa,fo_2=10(-39)～10^(-41),fs_3=10^(-12)～10^(-15),为中深中温岩浆热液银矿床。这类矿床是我国银矿新类型,许多方面与焦家式破碎带蚀变岩型金矿成矿特征相似,在粤西、桂东极具远景。
Based on geological, mineral inclusion and isotope geochemical studies,the authors old that the Pangxidong silver deposit is controlled by a ductilebrittle shear structural zone ith its mineralization related to Yanshanian syntectic granite. Wail rock alterations include ntense K-feldspathization and pyrite phyllic alteration. The ore-forming fluids are haracterized by K>Ca >Na>Mg,SO_4^(2-)>CI->HCO_3->F, CO>>CO_2>CH4_4,low salinity (2.2wt％～wt％ aCI) ,weak acidity (pH=4.6) and density 0.81. The ore-forming temperature 270℃, pressure 70010~5 Pa, fo_2 10^(-39)～10^(-41) and fs_2 10^(-12)～10(-15), indicating that the silver eposit is a mesothermal one.As a new type of silver deposit in China, this ore deposit bears trong resemblances to the Jiaojia gold deposit which also occurs in fracture zones and has een ntensely altered. Gold prospects for this type of silver deposits exist in west Guangdong and ast Guangxi.
出处
《矿床地质》
CAS
CSCD
北大核心
1992年第2期179-187,共9页
Mineral Deposits
