甘肃大水闪长岩型金矿床的矿物地球化学特征  

MINERAL GEOCHEMISTRY IN THE DASHUI DIORITE-TYPE GOLD DEPOSIT,GANSU PROVINCE

作　　者：李红阳[1] 李英杰[1] 袁万明[2] 杨秋荣[1] 康桂玲[1] 曹积飞[1] 

机构地区：[1]石家庄经济学院勘查技术学院,石家庄050031 [2]中国科学院高能物理研究所,北京100039

出　　处：《地质与勘探》2007年第4期41-45,共5页Geology and Exploration

基　　金：国家自然科学基金项目(编号:40272088);科技部"十五"攻关项目(编号:2001BA609A-07-03)联合资助

摘　　要：大水金矿氧化带下部,发育大量的微细粒浸染状、细脉状黄铁矿和黄铜矿,并出现砷黝铜矿。地表氧化矿中的赤铁矿,是黄铁矿等原生硫化物氧化所致;在矿石矿物成分上,黄铁矿、黄铜矿和砷黝铜矿的Au含量普遍较高。黄铁矿中的Co/N i比值多大于2,与岩浆成因黄铁矿相吻合。流体包裹体均一温度为105℃～400℃。3δ4S=-1.8‰～+4.1‰,1δ3C=-2.7‰～+4.3‰,1δ8O=6.63‰～19.42‰,δD=-101‰～-75‰。成矿流体主要来源于岩浆热液,碳、硫和成矿元素主要来源于赋矿闪长岩体,为富硫化物的闪长岩型金矿床。砷黝铜矿对找矿与勘探有指示作用。Large amounts of fine disseminated and veinlet pyrite and chalcopyrite with the presence of tennantite occur in the unoxidized zone below the oxidized zone in the Dashui gold deposit. Pyrite, chalcopyrite and other sulfides were oxidized into hematite in the oxidized ores. Electron microprobe analysis indicates that gold is richening in pyrite, chalcopyrite and tennantite. Co/Ni ratios from pyrite are mostly greater than 2, being consistent with those of magma - type pyrite. Fluid inclusion data in calcite indicate that homogenization temperatures are about 105℃ to 400℃. Isotopic data show that 3δ4S values of pyrite range from -1.8‰～＋4.1‰,δ13C values of calcite from -2.7‰ to ＋4.3‰, and δ13C and δD values of calcite from ＋6.63‰ to ＋ 19.42‰ and - 101‰ to - 75‰ respectively. Ore - forming fluids were largely magma water. Carbon, sulfur and metallogenic elements chiefly came from the hosted diorite. The gold deposit is a sulfides - rich diorite - type. Tennantite may be served as an important indicator for ore searching and prospecting.

关 键 词：闪长岩型金矿床 矿物地球化学 甘肃大水 

分 类 号：P618.51[天文地球—矿床学] P578.2[天文地球—地质学]