东天山康古尔金矿床成矿物源的同位素地球化学特征

STUDIES OF ISOTOPE GEOCHEMISTRY FOR ORE FORMING MATERIAL ORIGIN OF KANGGUL GOLD DEPOSIT, EAST TIANSHAN

康古尔金矿床属晚古生代火山岩区剪切带蚀变岩型金矿。同位素地球化学研究表明，矿石中铅为正常铅，热液系统硫同位素组成为陨石硫型，矿石中碳、钕同位素组成具深源特征，同时矿石与火山岩围岩中的Ｓｉ、Ｓｒ、Ｓ、Ｐｂ等同位素组成相近，说明成矿物质主要来自矿体围岩———火山岩，晚期有少量来自矿区附近的侵入岩。铅、锶同位素组成反映成矿过程中也有少量壳源物质的加入。

Kanggul gold deposit is located in north rim of the Aqishan Yamansu island arc zone of the Tarim plate, the eastern Tianshan Mountain. The distribution of the gold ore bodies is strictly controlled by the brittle ductile shear deformation zone. The ore bodies are composed of altered rocks and a few quartz veins. The studies of isotope geochemistry show that ore lead isotope is normal lead; sulfur isotopic composition of hydrothermal system is characteristic of meteorite sulfur; carbon and neodymium isotopic compositions of the ores are characteristic of deep source; Si, Sr, S, Pb isotopic compositions of the ores are closed to the surrounding volcanic rocks. It is indicated that ore forming materials came mainly from the surrounding volcanic rocks, and a few materials came from intrusive rockbody near the mining area. Pb, Sr isotopic compositions also show that a few materials of crust origin entered ore forming hydrothermal system.