摘要
九八年以来,在内蒙大青山地区古元古界二道洼群地层中陆续发现了一批以卯独庆金矿为典型代表的层控特征十分明显的新类型金矿。二道洼群是一套大陆裂谷盆形碎屑岩建造,以杂砂岩、碳酸岩、砂质泥岩、粘土岩为主,上部夹中基性火山岩建造;变质从低绿片岩相到低角闪岩相,变形复杂。金矿体产于固定的层位二道洼群红山沟组的云母片岩和大理岩中,受顺层滑脱作用形成糜棱岩化带控制,矿化均匀,厚度大,平均品位可达6×10-6以上,最高达23×10-6。矿石矿物成分主要有银金矿、黄铁矿、黄铜矿、方铅矿等。成矿时代早于中元古代。而且该类金矿物化探异常显示良好,Au、Ag、Cu、Pb四种元素为矿体晕元素组合。这些特征都表明其成矿作用具特殊性,与产于内蒙新太古界乌拉山群及色尔腾山群中的金矿类型完全不同。因此,有必要对该类金矿的成矿机制及成矿时代进行重新认识。
Several new types of stratum-controlled gold deposits were found in Paleoproterozoic Erdaowa Group since 1998, in which Maoduqing gold deposit is the most typical one. Erdaowa Group is made of clastic carbonate rocks formed in the continental rift basen. The metamorphizm is from low greenschist to low horblende facies. The gold deposit is in the mica schist and marble of the fexed stratum Hongshangou Fotmation, Erdaowa Group, and cotrolled by the bedding detachment mylonitized zone. The thickness of the ore body is big with mineralizition uniformity. The gold average grade is 6×10-6. And the highest grade is 23×10-6.The ore mineral members are electrum,pyrite,chalcopyrite,galena et al.The metallogenetic epoch is before Midproterozoic. The geochemical exploration anomaly element Au,Ag,Cu and Pb combination is the ore body primary halo,and displayed clearly. The mineralization of this kind of the gold ore is of particularity, and different from those formed in Newarcheozoic Wulashan Group and Se'ertongshan Group Innermogolia.
出处
《地质调查与研究》
2003年第3期177-182,共6页
Geological Survey and Research
关键词
内蒙大青山
卯独庆金矿
层控矿床
古元古界
二道洼群
红山沟组
成矿作用
Daqingshan Innermongolia
Maoduqing gola deposit
stratum controlled ore
Paleoproterozoic
Erdaowa Group
Hongshangou Formation
mineralization
