矿床地质2012，Vol.31Issue(5)：999-1013,15.
新疆阿吾拉勒成矿带西段铜矿床碳、氧、硫、铅同位素研究——成矿物质来源及成矿环境探讨
Carbon, oxygen, sulfur and lead isotope constraints on the ore source and metallogenesis of copper deposits in western Awulale Mountain metallogenic belt, Xinjiang
摘要
Abstract
The copper deposits distributed in western Awulale Mountain metallogenic belt include subvolanic rock-related Cu deposits (SVR) situated in the middle and southern area and intermediate-low temperature hydrother-mal vein-type Cu deposits (ILTHV) located in the northern area. This paper reports a detailed C, O, S and Pb isotopic investigation of three SVR deposits (No. 109, Qunjisayi and Qunji) and two ILTHV deposits (Nulasai and Qiongbulake) lying from south to north in the ore field. The sulfur isotopic compositions of the sulfides from the five deposits show distinct differences and systematic variations from south to north. The SVR deposits show small variation of δ34S values from + 3.4%o to +4.4%o (No. 109 deposit) and from - 1.6%o to 0.2%o (Qunjisayi and Qunji deposits). In contrast, the ILTHV deposits have large variation of S^S values from - 18%o to + 8.9%o. The carbon and oxygen isotope variations of the two types have similar sulfur isotope variation features. The SVR deposits show small variation of δ13C values from - 1.44%o to + 0.8%o and relatively large variation of δ18O values from + 11.87‰ to + 16.99‰. The ILTHV deposits have large variation of δ13C values from - 10.1% to -3.2% and relatively large variation of δ18O values from 9.63% to 16.27%. The Pb-isotopic composition of sulfides from ILTHV deposits indicate that they are normal-Pb mainly derived from the mantle. The Pb-isotope of sulfides from felisic SVR deposits is rich in radiogenetic Pb provided by the Precam-brian basement rock. The Pb-isotope of sulfides from basic SVR deposits is the mixed mantle-Pb and crust-Pb. In conclusion, the systematic variations of mineral source and ore-forming process from SVR deposits to ILTHV deposits reveal that the metallogenic environments in southern and northern copper belt are different and this dif-ference was probably related to the Permian rifting evolution. In the process of Permian rifting evolution, the different extents of the stretching structure in southern and northern copper belt caused different volcanic rocks and sedimentary strata which constituted the ore-source bed. The formation of different Cu deposit types in different positions was controlled by the difference in mineral sources and intensities of continental volcanism caused by the Permian rifting.关键词
地球化学/稳定同位素/成矿物质来源/成矿环境/阿吾拉勒成矿带西段/新疆Key words
geochemistry/ stable isotope/ mineral source/ metallogenic environment/ western Awulale Mountain metallogenic belt/Xinjiang分类
天文与地球科学引用本文复制引用
赵军,张作衡,刘晓阳,刘敏,张贺,朱维娜..新疆阿吾拉勒成矿带西段铜矿床碳、氧、硫、铅同位素研究——成矿物质来源及成矿环境探讨[J].矿床地质,2012,31(5):999-1013,15.基金项目
本文得到国家科技支撑计划(编号:2011BAB06B02-05)和地质矿产调查评价项目(编号:1212011085060)的联合资助 （编号:2011BAB06B02-05）
