现代地质2012,Vol.26Issue(2):229-242,14.
云南羊拉铜矿床矿物组成、地球化学特征及其地质意义
Mineral Composition, Geochemistry of the Yangla Copper Deposit in Yunnan and Their Geological Significances
摘要
Abstract
The Yangla copper deposit, situated in the middle section of Jinshajiang tectonic belt between Zhongza-Zhongdian plate and Changdu-Simao plate, is a representative and giant copper deposit that has been discovered in Jinshajiang-Lancangjiang-Nujiang region in recent years. Metalliferous minerals consist of chal-copyrite, pyrite, pyrrhotite, galena, bismuth, bismuthinite, arsenopyrite, cobaltite and molybdenite. Based on the mineral association, the paper infers that the deposit is a medium to high temperature hydrothermal deposit. There is a coupled relationship between Yangla granodiorite and copper mineralization in the Yangla copper deposit. A comparison of the REE and trace element compositions of the copper ores with those of the Yangla granodiorite, and S, Pb isotopic composition of the Yangla copper deposit indicate that the ore-forming fluids are derived mainly from the mantle, with minor contributions from the magma. In the late Early Permian, the Jinshajiang oceanic plate was subducted to the west, resulting in the formation of a series of gently dipping thrust faults in the Jinshajiang tectonic belt, meanwhile, accompanied magmatic activities. In the early Late Triassic, which was a time of transition from collision-related compression to extension in the Jinshajiang tectonic belt, thethrust faults were tensional, it would have been a favorable environment for ore-forming fluids. The ascending magma provided a channel for the ore-forming fluid from the mantle wedge. After the magma arrived at the base of the early-stage Yangla granodiorite, the platy nature of the granodiorite body would have shielded the late-stage magma from the fluid. The magma cooled slowly, and some of the ore-forming fluid in the magma moved along a gently dipping thrust faults near the Yangla granodiorite, resulting in mineralization.关键词
羊拉铜矿床/矿物组成/稀土元素/微量元素/S、Pb同位素/云南Key words
Yangla copper deposit/ mineral composition/ rare earth element/ trace element/ S, Pb isotope/ Yunnan分类
天文与地球科学引用本文复制引用
杨喜安,刘家军,韩思宇,汪欢,罗诚,刘月东,翟德高..云南羊拉铜矿床矿物组成、地球化学特征及其地质意义[J].现代地质,2012,26(2):229-242,14.基金项目
国家重点基础研究发展计划项目(2009CB421003,2009CB421005) (2009CB421003,2009CB421005)
高等学校学科创新引智计划项目(B07011). (B07011)