摘要
新疆阿舍勒铜矿是我国近十多年来找到的一个大型海相火山岩型块状硫化物多金属矿床,在经济上和矿床学上都有重要意义。阿舍勒铜矿的容矿岩是早-中泥盆世阿舍勒组海相火山岩,具特征的双峰式组合,缺少含SiO_254％-61％的中性岩,在地表和钻孔都经常见到基性与酸性火山岩紧密互层现象。稀土和微量元素地球化学表明基性、酸性火山岩来自两个不同的源区。矿石铅同位素组成与细碧岩一致,硫同位素呈典型塔式分布,表明成矿物质和火山岩一样来自深部。因此,阿舍勒铜矿的形成受拉张构造条件下双峰式火山作用的控制。
The Devonian marine spilite-keratophyre association in the Ashele copper deposit, Xinjiang, bears typical characteristics of bimodal volcanic rocks, because basic and acid volcanic rocks may be often found to alternate closely with each other on the surface and in cores of drill holes and intermediate rocks with 54%-61% SiO2 are lacking, especially in the Early-Middle Devonian Ashele Formation which hosts bedded copper orebodies. Rare earth element and minor element geochemistry of bimodal volcanic rocks indicate that the basic and acid volcanic rocks originated from different sources rather than a common magma chamber. The lead isotopic composition of ores is consistent with that of spilite, and sulfur isotopes show a distribution of tower type, illustrating that both ore-forming and rock-forming materials were derived from depths. So the Ashele Cu-Zn polymetallic ore deposit is of a volcanic-type massive sulfide deposit, controlled by continental-margin marine bimodal volcanism occurring in an extensional setting in the Devonian.
出处
《地质论评》
CAS
CSCD
北大核心
1996年第1期45-53,共9页
Geological Review
关键词
双峰式火山岩
铜矿床
成矿环境
矿床构造
bimodal volcanic rocks, metallotectonic environment, rifting, volcanic-type massive sulfide Cu deposit, Ashele, Xinjiang
