甘肃文县地区阳山超大微细浸染型金矿床的成因与类型  

Genesis and types of the Yangshan superlarge micro-disseminated gold deposit,Wenxian,Gansu,China

作　　者：程斌[1] 张复新[1] 贺国芬[1] 

机构地区：[1]西北大学大陆动力学国家重点实验室,西北大学地质学系,陕西西安710069

出　　处：《地质通报》2006年第11期1354-1360,共7页Geological Bulletin of China

基　　金：西北大学创新基金项目(编号:XDCX-04-04);国家自然科学基金项目(编号:40572065)资助。

摘　　要：含矿岩石为本区泥盆系的一套Au含量较高的炭-硅-泥质地层。其中发现大量含As异常(含As约0.15%)的草莓状黄铁矿;矿体沿断裂带呈构造透镜体-扁豆体斜列等间距分布,产于断裂带中次级破碎带或顺层剪切带内;在早—中期阶段的矿化硫化物中,金以不可见金赋存于含As黄铁矿及毒砂中,含As黄铁矿发育增生环带,载金矿物主要沿片理化带呈微细浸染状分布;在中—晚期阶段的金属硫化物-石英碎裂脉体中,可见显微颗粒金;斜长花岗斑岩为地壳重熔型花岗岩,具多期次性;H、O、S同位素及流体包裹体资料表明,成矿流体以大气降水为主,岩浆水也参与成矿。由此可见,阳山金矿具沉积-岩浆叠加-构造及热液改造的多因复成特征,矿床属超大型卡林-类卡林复合型金矿床。The ore-bearing rocks in the Yangshan gold deposit, Wenxian, Gansu, are a sequence of Devonian carbonaceous-siliceous-argillaceous sediments, which contains abundant framboidal pyrite with As anomaly （-0.15% As）. Orebodies occur as tectonic lenses or pods equidistantly along the secondary fractured zone or bedding-parallel shear zone in a fault belt. In mineralized sulfide in the early-middle phase, Au occurs as invisible gold in As-bearing pyrite and arsenopyrite. As-bearing pyrite displays overgrowth zoning. The Au carriers mainly occur as micro-disseminations along the schistose zone. Microscopic gold grains are visible in metal sulfide-quartz crushed veins formed in the middle and late phases. Plagiogramte porphyry is crustal anatectic granite formed by multiple intrusions. H, O, and S isotope and fluid inclusion data indicate that ore fluids consist mainly of meteoric water mixed with small amount of magmatic water. Thus it follows that the Yangshan gold deposit is a superlarge Carlin and Carlin-like type polygenetic gold deposit with rnagma-telescoped, sedimentary and tectonically and hydrothermally modified features.

关 键 词：卡林-类卡林复合型金矿 阳山金矿 南秦岭 

分 类 号：P618.51[天文地球—矿床学]