新疆卡拉盖雷铜矿隐爆角砾岩地质特征及控矿作用

卡拉盖雷铜矿床是那提拉构造成矿带内发现的火山岩型铜矿床,矿体赋存于下石炭统大哈拉军山组火山岩地层中的隐爆角砾岩、硅化蚀变岩和片理化蚀变凝灰岩中。结合前人研究成果,对隐爆角砾岩的形态特征、岩石特征和岩相分带及其成矿控制作用进行了分析研究。研究表明:隐爆角砾岩筒受区域韧性剪切带和环形构造次级断裂的共同控制,为一向南陡倾的筒状体,主要由霏细岩和角砾岩组成,岩相简单,Ⅴ号主矿体整体产于角砾岩筒的爆破相角砾岩带,矿化蚀变分带、矿体形态、产状、规模及定位严格受角砾岩筒控制,为上部富集Au、Pb、Zn,下部富集Co、Au的铜矿床。其他矿体产状及矿化蚀变分带同样受控于隐爆角砾岩筒。因此,隐爆角砾岩及与矿化有关的硅化、电气石化、绿泥石化及碳酸盐化等蚀变是寻找类似火山机构及次火山岩型矿床的重要标志。

Breccia Pipe and Its Constrain on Copper Mineralization in Kalagailei Mine,Xinjiang Province

As one volcanic-hosted deposit,the Kalagailei copper deposit in Xinjiang is hosted in Dahalajunshan Formation volcanics of Lower Carboniferous.Orebodies occur in a breccias pipe,silicified rocks and altered tuff with well-developed schistosity.Combined with previous research on the morphological characteristics of the hidden breccia,rock facies characteristics and the control action zonation and mineralization were analyzed.It is manifested that breccia pipe dipping south is controlled by regional ductile shear zone,circular structure and secondary faults, and mainly composed of brecciaed felsite.No.5 ore body is hosted within explosive breccia pipe,and its zonation, shape,attitude and size are controlled by the breccia pipe.Mineralization displays clear zonation with Au,Pb,Zn enrichment at upper and Co,Au enrichment at lower.Other orebodies,mineralization zoning and alteration zoning are also controlled by the breccia pipe.Consequently,breccias pipe and its related alteration such as silicification, tourmaline alteration,chloritization and carbonitization are the significant index for prospecting of subvolcanic ore deposits hosted in breccia pipe.These index can be used as an important guide for prospecting in its periphery.