南疆斯如依迭尔铜多金属矿床的地质特征及其成矿时代

Geological Characteristics and Mineralogenetic Epoch of the Siruyidie'er Copper Polymetallic Deposit,South Xinjiang

近些年发现的斯如依迭尔铜多金属矿床有望改变南疆无大—中型铜矿的局面,对其研究意义显著。该矿床已圈定铜多金属矿体32条及众多矿化蚀变点,成矿前景乐观。矿床由南、北两矿段组成。北矿段主体由13个隐爆角砾岩体组成,隐爆角砾岩体内发育黄铜矿化;南矿段在花岗斑岩与围岩的接触带发育脉状黄铜矿化,岩体内部发育细脉状和浸染状黄铜矿化。上述地质特征表明,斯如依迭尔矿床为与花岗斑岩有关的斑岩型铜多金属矿床。对斯如依迭尔矿床成矿期的热液白云母进行40 Ar/39 Ar同位素测年,获得的坪年龄为13.68±0.17 Ma,表明矿床形成于中新世。结合前人的区域地质背景和构造演化研究结果,笔者认为斯如依迭尔铜多金属矿床的成矿地质背景与冈底斯中新世斑岩型铜金矿床的相同,均为印度板块同欧亚板块碰撞后的伸展环境。

Newly discovered Siruyidie’er copper polymetallic deposit is likely to change current situation that there are few large and medium-scaled copper deposits in South Xinjiang,and this has great significance for the study of mineralization in this area.The 32copper orebodies and numerous mineralized-altered spots have been determined and have huge metallogenic potential.The Siruyidie’er copper polymetallic deposit can be divided into south ore block and north ore block.The north ore block contains 13cryptoexplosive breccia pipes,with disseminated chalcopyritization occurring in cryptoexplosive breccia pipes.In the south ore block,vein-type chalcopyritization mainly occurs in contact zones of granite porphyry and wall rock,with veinlet and disseminated chalcopyritization developed in granite porphyry.These geological characteristics show that themetallogenic hydrothermal muscovite from the Siruyidie’er copper polymetallic deposit yielded a plateau age of13.68±0.17Ma,suggesting that the deposit formed in Miocene.Based on regional geological setting and tectonic evolution,this study suggests that the Siruyidie’er copper polymetallic deposit has a similar geological setting to the Miocene Gangdise porphyry Cu-Au deposits,both of which formed in a post-collisional extension environment of Indo-Asian continent collision.