In situ LA-MC-ICP-MS and ID-TIMS U¨CPb geochronology of cassiterite in the giant Furong tin deposit, Hunan Province, South China: New constraints on the timing of tin¨Cpolymetallic mineralization

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• 作者：Shunda  ; Yuan^a ;   ; ^b ;   ; ^c ;   ; ^{sdyuan011981@yahoo.com.cn} ; Jiantang  ; Peng^c ;   ; ^d ; Shuang  ; Hao^e ; Huimin  ; Li^e ; Jianzhen  ; Geng^e ; Dongliang  ; Zhang^c ;   ; ^d
• 关键词：Cassiterite ; U&ndash ; Pb dating ; LA-MC-ICP-MS ; ID-TIMS ; Furong giant tin deposit
• 刊名：Ore Geology Reviews
• 出版年：2011
• 出版时间：December 2011
• 年：2011
• 卷：43
• 期：1
• 页码：235-242
• 全文大小：1342 K

文摘

The Furong deposit, located in southern Hunan Province, China, is a newly-discovered giant tin deposit spatially associated with the A-type Qitianling granite. The petrogenetic link between the giant Furong tin deposit and the Qitianling granite batholith remains controversial because of the lack of precise dating for the tin¨Cpolymetallic mineralization. Here we report for the first time in-situ U¨CPb data on cassiterite obtained by LA-MC-ICP-MS and the results are compared to ID-TIMS data. The in-situ LA-MC-ICP-MS analyses of the cassiterites provide a reliable age constraint for tin¨Cpolymetallic mineralization in the Furong deposit, yielding an isochron age of 159.9 ¡À 1.9 Ma (at 95 % confidence level, MSWD = 18), which is indistinguishable from the ID-TIMS ²⁰⁶Pb/²³⁸U weighted mean age of 158.2 ¡À 0.4 Ma. The in situ U¨CPb ages corroborate the Ar¨CAr dates published for the Furong tin deposit, which indicate that the mineralization is coeval with the emplacement of the Qitianling granite batholith. These results provide further evidence of a close temporal link between the pluton's emplacement and tin mineralization in the Furong area. The data obtained clearly demonstrate that in-situ LA-MC-ICP-MS U¨CPb dating of cassiterite is a robust geochronometer for direct dating of tin¨Cpolymetallic mineralization.