南秦岭震旦系中发现微细浸染型金矿

南秦岭震旦系中发现微细浸染型金矿隗合明（西安地质学院，西安７１００５４）关键词震旦系，微细浸染型金矿，矿源层，韧－脆性剪切带，南秦岭８０年代以来，黔东南、桂西北、川西北、南秦岭等地区相继发现了微细浸染型金矿带和一批较大规模的金矿床，由此我国的金矿地质...

Discovery of Veinlet Disseminated Gold Deposit in Sinian System in South Qinling

Not long ago,a veinlet disseminated gold ore deposit was discovered in South Qinling in western Henan Province,China,and it is expected that additional gold ore deposits will be found in this area.The ore bodies are located in epimetamorphic microclastic rock and carbonate formation,stratagraphically belonging to the middle part of Doushantuo Formation of Sinian em.The ore bodies,which are bedlike or lenticular,occur steadily near the boundary between the microclastic rocks and the carbonates.The host rock mainly is phyllites. Primary studies indi cate that the formation of the ore deposit ismainly controlled by the sedimentary strata,the ductile brittle shear zone and the ticline structure.According to the types of host rocks,the ores can be classified into two ypes:the silica rock type and the silicate phyllite type.The composition of the ores is simple,including pyrite and minor pyrite and galena,quartz,sericite,dolomite,calcite and kaolinite min erals.The pyrites are fine and disseminated.The gold is in supermicroscopic form and occurs in the microfracture and surfaces of rite,arsenopyrite and quartz.It is also found that gold is absorbed by clay minerals in this gold deposit.