甘肃省文县阳山金矿床地质及同位素特征

阳山金矿床位于陕甘川交界地带,在大地构造位置上属西秦岭南亚带.矿床产于中泥盆统三河口组浅变质岩地层中,受文县弧形构造控制.矿体在平面上呈舒缓波状,在剖面上为脉状、似层状,矿石中金属矿物主要有黄铁矿、毒砂和辉锑矿,金主要以微细粒金赋存于黄铁矿、毒砂和黏土矿物中.矿床的钾-氩、氩-氩、氢、氧、硫、碳同位素研究表明,阳山金矿形成于侏罗纪早期(195Ma),与区域上三叠纪末期-侏罗纪早期的岩浆-构造活动关系密切,其不同于典型的卡林型金矿以及类卡林型金矿,其成矿流体及成矿物质均与岩浆热液活动有关.

GEOLOGY AND ISOTOPE CHARACTERS OF YANGSHAN GOLD DEPOSIT, GANSU

Yangshan gold deposit,located in the border area of Shanxi,Gansu and Sichuan provinces,belongs to the south Subzone of the west Qinling structure belt.The deposit is distributed in the middle Devonian Sanhekou formation epimetamorphic strata,and controlled by Wenxian arc structure.Ore bodies show gentle wave-like in plane and tabular and vein-like forms in profile.Ore minerals are mainly pyrite,arsenopyrite and zinckenite,and gold(mainly electrum) usually occurs as micro-grained inclusions in pyrite,arsenopyrite and argillaceous.Isotope analyses of K-Ar,Ar-Ar,H,O,S and C show that Yangshan gold deposit was formed in the early Jurassic,and related to strong magmatic-tectonic activities in the area from late Tertiary to early Jurassic.The deposit is different from typical Carlin-type gold deposit and Carlin-like gold deposit.Ore-forming fluids and materials are related to magmatic hydrothermal activities.