新疆吐克吐克铜矿黄铜矿Re-Os定年及成矿意义

吐克吐克铜矿为笔者新发现,产于新疆西准噶尔构造带南部,成矿时代尚缺乏精确的同位素年代学制约。该矿床硫化物组合单一,主要为黄铜矿。本文选择了8件黄铜矿样品,进行Re-Os法定年。结果得到了较好的效果,所有样品的Re含量为39.7×10~(-12)~2440.6×10~(-12),~(187)Os含量为1.2×10~(-12)~9.0×10~(-12),给出的等时线年龄为288.3±8.8Ma。这表明该区Cu的成矿作用与晚石炭世—早二叠世区域峰期岩浆活动一致,证实该区仍存在较大找矿空间。

Re-Os Geochronology of the Tuketuke Cu Deposit in Western Junggar, NW China and Its Metallogenic Significance

The Tuketuke copper deposit, discovered in 2010, is located in the West Junggar region of Xinjiang of northwest China. The deposit is hosted within the Xiaerpu granodiorite (named No.956 highland pluton in the past) that intruded into Early Carboniferous sedimentary strata and its exo-contact zone. Re-Os dating for eight Chalcopyrite samples obtained from three prospecting engineering in the deposit yield a Re-Os isochron age of 288.3±8.8 Ma (2sigma), with an initial 187Os/188Os of 0.0 ± 1.1, a variety of Re content from 39.7×10-9 to 2440.6×10-9, and relative low content of 187Os from 1.2×10-9 to 9.0×10-9. The Re-Os isochron age of the molybdenite is consistent with the peak ages of the magmatic activity in the West Junggar region, which indicates that the deposit is genetically related with an Early Permian metallogenic system. This consistency suggests the relative large potentiality of finding more Cu deposits in the belt.