【作者】 岳树勤； 陈殿芬； 孙淑琼； 王文瑛；

【Author】 Yue Shuqin Chen Dianfen Sun Shuqiong Wang Wenying (Institute of Mineral Deposits,Chinese Academy of Geological Sciences)

【机构】 矿床地质研究所；

【摘要】 <正>一、矿床地质概况本矿床处于康滇地轴与松潘地槽交汇处的丹巴复背斜东南侧的银厂沟短轴背斜轴部, 产于岩席状的超基性岩体内。岩体由二辉橄榄岩、斜辉辉橄岩和辉长岩等组成,顺层侵入于石炭纪大雪组的石英岩、硅质大理岩、泥质板岩及绢云石英片岩等地层中。铜镍硫化物主要赋存于岩体中、下部强烈蛇纹石化、滑石化及次闪石化的橄榄岩中。更多还原

【Abstract】 The deposit in question occurs within a sheet-like ultrabasic body loca- ted along the axis of the Yinchangguo brachyanticline on the southeastern side of Danba anticlinorium at the juncture of Kangdian earth′s axis and Songpan geosyncline. Composed essentially of lherzolite,harzburgite and gabbro,the ultrabasic body intruded conformably quartzite,siliceous marble of Carboniferous Daxue Group.Confined mainly to the intensely-altered harzburgite in the middle and lower part of the ultrabasic body,platinum-bearing copper-nickel sulfide orebodies consist chiefly of massive,disseminated and taxitic ores,the first two sorts occurring mainly within the ultrabasic body while the last one present where the ultrabasic body meets silicious marble. Sulfides and arsenosulfides constitute the majority of the metallic min- erals.Among them,the most widely spread are pyrrhotite,pentlandite,cha- lcopyrite,violarite and pyrite;cobaltite,ilmenite,chromite and magnetite are relatively less seen;there also exist minor amounts of cubanite,native gold,danbaite and native chromium. The ore deposit possesses rather complicated multiple ore-forming proces- ses,which lasted from magmatic period to hydrothermal stage.Quite a number of mineral assemblages have been recognized,the most important of which are: 1.Chromite-magnetite-peridotite assemblage—a product of magmatic dif- ferentiation. 2.Pyrrhotite-pentlandite-chalcopyrite assemblage,representing the pro- duct of late magmatic differentiation. 3.Pyrrhotite-pentlandite-chalcopyrite-serpentine(or hornblende)assem- blage,formed by sulfidization under pneumato-hydrothermal process during the post magmatic stage. 4.Pyrrhotite-chalcopyrite-pentlandite-garnet assemblage,generated th- rough the replacement of marble during the post magmatic stage and chara- cterized by the increase in hexagonal pyrrhotite and the augmentation in size of its crystal. 5.Chalcopyrite-pyrite assemblage—a possible product of residual hyd- rothermal fluids,penetrating the country rocks as veins. 6.Chalcopyrite-galena-sphalerite-carbonate assemblage,resulting from the hydrothermal polymetallic activity. 7.Galena-tetradymite assemblage,characterized by the coarse idiomor- phic galena crystal which infills the druse in the late quartz vein and has an exceedingly perfect octahedron cleavage filled by scaly tetradymite crys- tals. Nine minerals of platinum family elements have been recognized by means of artificial concentration of placer minerals,they are antimonian michenerite,bismuthian testebiopalladite,sudburyite,antimonian palladian hexatenickelite,sperrylite,erlichmanite and,to a much less amount,omeiite, platinum,osmruthendiarsenite. Detailed investigation has been made of the physical,optical and che- mical properties of these nine minerals,which shows that platinum family elements occur mainly as independent minerals and partly as impurities dis- persed in sulfides such as pyrrhotite,pentlandite and chalcopyrite.更多还原