The zircon SHRIMP dating age for the Shangyou granites is 464±11 Ma. The geological feature of the pluton is consistent with the isotopic age, which shows that it is a product of Caledonian orogenesis. The Shangy...The zircon SHRIMP dating age for the Shangyou granites is 464±11 Ma. The geological feature of the pluton is consistent with the isotopic age, which shows that it is a product of Caledonian orogenesis. The Shangyou granites are regarded as peraluminous crust-derived granites to possess the typical geochemical characteristics of calc-alkaline rocks on the active continental margin with enriched Si, K, Al （A/CNK -- 1.11 on average）, HREE, Rb, U, Th and heavily depleted V, Cr, Co, Ni, as well as Ti-Y, Nb-Ta, Zr, Sr, P and Ba, to be commonly corundum normative （av C -- 1.44）. The Shangyou granites with higher 87Sr/86Sr ratios （0.707126-0.712186）, ENd（t） values （-7.29 to -10.22） and （tDM） values （1.52-1.63 Ga）, which are considered to result from partial melting of continental crust metamorphic sedimentary rocks with relatively low of crust maturation degree corresponding to the Middle Proterozoic, to have some possible contributions of mantle-derived components. The Shangyou granites are regarded as post-collision granites, which were formed in a transitional tectonic setting from compression to extension in the Middle Ordovician period after the Yangtze plate was subducted beneath the Cathaysian plate. The Ar-Ar total ages of K-feldspar and biotite are 292.1 Ma and 295.5 Ma respectively, which have recorded information of a late-stage thermal alteration event.展开更多
0.INTRODUCTION.The Jiuwandashan Sn-polymetallic ore cluster,located in the western part of the Jiangnan Orogen and the Nanling Metallogenic Belt,is one of the most significant Precambrian tin ore concentration areas i...0.INTRODUCTION.The Jiuwandashan Sn-polymetallic ore cluster,located in the western part of the Jiangnan Orogen and the Nanling Metallogenic Belt,is one of the most significant Precambrian tin ore concentration areas in South China(Figure 1a;Mao et al.,1987).Recently,this region has garnered considerable research attention due to its intense mafic-felsic magmatic activity and large-scale Sn-polymetallic mineralization(Li et al.,2020;Chen J F et al.,2019;Huang and Wang,2019;Zhang et al.,2019;Chen L et al.,2018;Xiang et al.,2018;Su et al.,2014).A series of medium-to large-scale Sn-polymetallic deposits,including Jiumao,Liuxiu,Yidong,Honggangshan,and Shaping(Figure 1b),have been identified within this region,with proven tin reserves of approximately 200000 t.High-precision dating methods have yielded cassiterite U-Pb ages of ca.830 Ma,pointing to a Neoproterozoic Sn-polymetallic mineralization event in South China(Zhang et al.,2019;Xiang et al.,2018).展开更多
文摘The zircon SHRIMP dating age for the Shangyou granites is 464±11 Ma. The geological feature of the pluton is consistent with the isotopic age, which shows that it is a product of Caledonian orogenesis. The Shangyou granites are regarded as peraluminous crust-derived granites to possess the typical geochemical characteristics of calc-alkaline rocks on the active continental margin with enriched Si, K, Al （A/CNK -- 1.11 on average）, HREE, Rb, U, Th and heavily depleted V, Cr, Co, Ni, as well as Ti-Y, Nb-Ta, Zr, Sr, P and Ba, to be commonly corundum normative （av C -- 1.44）. The Shangyou granites with higher 87Sr/86Sr ratios （0.707126-0.712186）, ENd（t） values （-7.29 to -10.22） and （tDM） values （1.52-1.63 Ga）, which are considered to result from partial melting of continental crust metamorphic sedimentary rocks with relatively low of crust maturation degree corresponding to the Middle Proterozoic, to have some possible contributions of mantle-derived components. The Shangyou granites are regarded as post-collision granites, which were formed in a transitional tectonic setting from compression to extension in the Middle Ordovician period after the Yangtze plate was subducted beneath the Cathaysian plate. The Ar-Ar total ages of K-feldspar and biotite are 292.1 Ma and 295.5 Ma respectively, which have recorded information of a late-stage thermal alteration event.
基金financially supported by the National Natural Science Foundation of China(No.42472117)China Geological Survey(Nos.DD20243431,DD20230342,DD20240064)。
文摘0.INTRODUCTION.The Jiuwandashan Sn-polymetallic ore cluster,located in the western part of the Jiangnan Orogen and the Nanling Metallogenic Belt,is one of the most significant Precambrian tin ore concentration areas in South China(Figure 1a;Mao et al.,1987).Recently,this region has garnered considerable research attention due to its intense mafic-felsic magmatic activity and large-scale Sn-polymetallic mineralization(Li et al.,2020;Chen J F et al.,2019;Huang and Wang,2019;Zhang et al.,2019;Chen L et al.,2018;Xiang et al.,2018;Su et al.,2014).A series of medium-to large-scale Sn-polymetallic deposits,including Jiumao,Liuxiu,Yidong,Honggangshan,and Shaping(Figure 1b),have been identified within this region,with proven tin reserves of approximately 200000 t.High-precision dating methods have yielded cassiterite U-Pb ages of ca.830 Ma,pointing to a Neoproterozoic Sn-polymetallic mineralization event in South China(Zhang et al.,2019;Xiang et al.,2018).
