SHRIMP zircon U¨CPb and molybdenite Re¨COs isotopic dating of the tungsten deposits in the Tianmenshan¨CHongtaoling W¨CSn orefield, southern Jiangxi Province, China, and geological implications

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• 作者：Chengyou  ; Feng^a ;   ; ^{fengchy@yahoo.com.cn} ; Zailin  ; Zeng^b ; Dequan  ; Zhang^a ; Wenjun  ; Qu^c ; Andao  ; Du^c ; Daxin  ; Li^a ; Hongquan  ; She^a
• 关键词：Tianmenshan&ndash ; Hongtaoling orefield ; SHRIMP zircon U&ndash ; Pb dating ; Molybdenite Re&ndash ; Os isotopic dating ; Tungsten deposits in southern Jiangxi Province ; China
• 刊名：Ore Geology Reviews
• 出版年：2011
• 出版时间：December 2011
• 年：2011
• 卷：43
• 期：1
• 页码：8-25
• 全文大小：3395 K

文摘

The southern Jiangxi Province is a major part of the Nanling W¨CSn metallogenic province of southern China, where all W¨CSn ore deposits are temporally and spatially related to Mesozoic granitic intrusions. The Tianmenshan¨CHongtaoling orefield is a recently explored territory endowed by several styles of W¨CSn mineralization. The orefield comprises three composite granitic plutons: Tianmenshan, Hongtaoling and Zhangtiantang associated with several tens of W¨CSn-polymetallic ore deposits (Maoping, Baxiannao, Niuling, Zhangdou, Yaolanzhai and others) along their contacts. In this study, four new SHRIMP zircon U¨CPb ages were determined for three composite granitic plutons, and 33 molybdenite samples from five W¨CSn deposits were analysed by ICP-MS Re¨COs isotopic method. SHRIMP zircon U¨CPb ages for both medium to coarse-gained biotite granite and porphyritic biotite monzogranite from the Tianmenshan composite pluton are 157.2 ¡À 2.2 Ma and 151.8 ¡À 2.9 Ma, respectively. Molybdenite Re¨COs isochron ages for the related Baxiannao fracture-controlled tungsten deposits are 157.9 ¡À 1.5 Ma. Maoping greisens-type tungsten deposits were emplaced at 155.3 ¡À 2.8 Ma and the Maoping wolframite¨Cquartz veins at 150.2 ¡À 2.8 Ma, respectively. The SHRIMP U¨CPb age of zircons from the Hongtaoling biotite granite is 151.4 ¡À 3.1 Ma whereas the molybdenite Re¨COs isochron ages of the genetically related Niuling endocontact tungsten quartz veins and Zhangdou exocontact tungsten quartz veins are 154.9 ¡À 4.1 to 154.6 ¡À 9.7 Ma and 149.1 ¡À 7.1 Ma, respectively. The SHRIMP zircon U¨CPb age of the Zhangtiantang fine-grained muscovite granite is 156.9 ¡À 1.7 Ma, whereas the molybdenite Re¨COs isochron age for the related Yaolanzhai greisens-type tungsten deposit is 155.8 ¡À 2.8 Ma. These new age data, combined with those available from the literature, indicate that the ages of W¨CSn ores and related granites are Late Jurassic with a peak at 150 to 160 Ma, which corresponds to the widespread Mesozoic metallogenic event in southern China. Molybdenites from this group of tungsten deposits have quite low Re contents (29.1 to 2608 ppb), suggesting continental crustal provenance of the ore metals.