Re–Os isotopic dating of molybdenite and pyrite in the Baishan Mo–Re deposit, eastern Tianshan, NW China, and its geological significance

被引：16
作者：
Lianchang Zhang
Wenjiao Xiao
Kezhang Qin
Wenjun Qu
Andao Du
机构：
[1] Chinese Academy of Sciences,Key Laboratory of Mineral Resources, Institute of Geology and Geophysics
[2] National Research Center of Geoanalysis,undefined
来源：
Mineralium Deposita | 2005年 / 39卷
关键词：
Re–Os isotopic dating; Mo–Re deposit; Geodynamic evolution; Eastern Tianshan;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
The Baishan Mo–Re deposit is located in the eastern section of the eastern Tianshan orogenic belt, NW China. The deposit has a grade of 0.06% Mo and a high content of rhenium of 1.4 g/t. Rhenium and osmium isotopes in sulfide minerals from the Baishan deposit are used to determine the age of mineralization. Rhenium concentrations in molybdenite samples are between 74 and 250 μg/g. Analysis of eight molybdenite samples yields an isochron age of 224.8±4.5 Ma (2σ). Pyrite samples have rhenium and osmium concentrations varying in the range 33.4–330.6 ng/g and 0.08–0.81 ng/g, respectively. Isotope data on seven pyrite samples yield an isochron age of 225±12 Ma (2σ) on the 187Re/188Os versus 187Os/188Os plot and an age of 233±14 Ma (2σ) on the 187Os versus 187Re correlation diagram. The ages of molybdenite and pyrite are consistent within the analytical errors. Combined with field observations, the data indicate that Mo–Re mineralization in the Baishan deposit is produced by a magmatic-hydrothermal event in an intracontinental extensional setting after late Paleozoic orogeny. The initial 187Os/188Os ratio of pyrite is 0.3±0.07. The δ34S values of molybdenite vary from +0.5 to +3.6‰. Both data indicate that mineralization is derived mainly from a mantle source.
引用
收藏
页码：960 / 969
页数：9
相关论文
共 146 条
[1]  
Allen MB(1992)Paleozoic collisional tectonics and magmatism of the Chinese Tianshan, central Asia Tectonophysics 220 89-115
[2]  
Windley BF(1993)Evolution of the Turfan basin, Chinese Central Asia Tectonics 12 889-896
[3]  
Zhang C(2003)A Re–Os study of sulfide minerals from the Bagdad porphyry Cu–Mo deposit, northern Arizona, USA Mineralium Deposita 38 585-596
[4]  
Allen MB(1998)Structure of the northern margin of Tarim massif (Eastern Kokshaal area, Tien Shan) Geotectonics 32 51-59
[5]  
Windley BF(2000)Diffusion of osmium in pyrrhotite and pyrite: implications for closure of the Re–Os isotopic system Earth Planet Sci Lett 180 399-413
[6]  
Zhang C(1999)The origin of the Jinwozi gold deposit in eastern Xinjiang-Evidence from isotope geochronology (in Chinese with English abstract) Geol Rev 45 247-254
[7]  
Guo JH(2003)A large-type quartz network-porphyry Mo deposit was discovered and proven in east Tianshan mountains (in Chinese with English abstract) Mineral Deposits 22 317-181
[8]  
Barra F(1995)A study of the rhenium-osmium geochronometry of molybdenites Acta Geol Sin 8 171-600
[9]  
Ruiz J(2003)Geochemistry and petrogenesis of a multi-zoned high Rb and F granite in eastern Tianshan (in Chinese with English abstract) Acta Petrol Sin 19 585-231
[10]  
Mathur R(2004)Re–Os age for molybdenite from the Gangdese porphyry copper belt on Tibetan plateau: implication for geodynamic setting and duration of the Cu mineralization Science in China (D) 147 221-230
12345678910