地球学报2012，Vol.33Issue(4)：613-623,11.DOI:10.3975/cagsb.2012.04.21
西藏曲水县达布斑岩铜(钼)矿床成岩成矿年代学研究
A Study of Diagenetic and Metallogenic Geochronology of the Dagbo Cu (Mo) Deposit in Quxur County of Tibet and Its Geological Implications
摘要
Abstract
Located in Quxu County of Tibet, the Dabu porphyry Cu-Mo deposit lies in the eastern part of the Gangdise belt. The authors made high-precision magmatic zircon dating of the granodiorite from the Dabu deposit. The U-Pb dating analyses show that the weighted mean ages of the porphyry from the main ore body are 16.5±0.05 Ma(n=13, MSWD=3, granodiorite) and 16.1±0.13 Ma(n=15, MSWD=1.03, monzonitic granite-porphyry) respectively. The U-Pb dating analyses indicate that the granodiorite from the Xianjiaonang ore body has the weighted mean age of 16.2±0.04 Ma(n=13, MSWD=0.0064). For the purpose of determining the mineralization time of the deposit, 4 molybdenite samples from the north and 6 molybdenite samples from the south were selected to conduct Re-Os dating. The Re-Os dating yielded isochron age of 14.6±0.50 Ma(MSWD=0.35, N) for the samples from the northern part and 14.8±0.23 Ma(MSWD=1.3, S) for the samples from the southern part of the deposit, respectively. Based on the results mentioned above in association with data available, it is proposed that crystallization of the porphyry occurred at about 16Ma, and the mineralization age of the deposits is about 14Ma, in a short period with time span shorter than 0.86Ma, implying the speciality of paroxysmal mineralization in the post-collision extension environment.关键词
西藏/冈底斯/达布斑岩Cu(Mo)矿床/锆石U-Pb年龄/辉钼矿Re-Os年龄/后碰撞伸展Key words
Tibet/ Gangdise/ Dabu Cu(Mo) deposit/ zircon U-Pb dating/ post-collision/ molybdenite Re-Os dating分类
天文与地球科学引用本文复制引用
高一鸣,陈毓川,唐菊兴,罗茂澄,冷秋锋,王立强,杨海锐,普布次仁..西藏曲水县达布斑岩铜(钼)矿床成岩成矿年代学研究[J].地球学报,2012,33(4):613-623,11.基金项目
本义由973项目"青藏高原南部增生造山成矿系统发育机制"(编号:2011CB403103)和青藏专项"西藏冈底斯东段中新生代斑岩成矿系统与找矿预测"(编号:1212011085529)联合资助. （编号:2011CB403103）
