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
Objective The Dajishan W-Ta-Nb deposit is located in the junction of southern Jiangxi and Guangdong Provinces(Fig. 1a). This deposit contains about 190, 000 tons of WO3 reserves,belonging to a super-large W deposit. M...Objective The Dajishan W-Ta-Nb deposit is located in the junction of southern Jiangxi and Guangdong Provinces(Fig. 1a). This deposit contains about 190, 000 tons of WO3 reserves,belonging to a super-large W deposit. Most W mineralization (mainly wolframite) at Dajishan occurred in quartz veins, with also some disseminated wolframite in the No. 69 granite.展开更多
The zircon SHRIMP dating of the Zhangtiantang granite gave an age of 159±7 Ma.,which shows that the granite was produced at the early Late Jurassic.The Ar-Ar plateau ages of biotite and K-feldspar from the Zhangt...The zircon SHRIMP dating of the Zhangtiantang granite gave an age of 159±7 Ma.,which shows that the granite was produced at the early Late Jurassic.The Ar-Ar plateau ages of biotite and K-feldspar from the Zhangtiantang pluton are 153.2±1.1 Ma and 135.8±1.2 Ma,respectively.The Ar-Ar anti-isochrone ages of biotite and K-feldspar are 152.5±1.7Ma and 135.4±2.7Ma,respectively.The ages represent the isotopic closure ages of minerals in the pluton.The Zhangtiantang granites are regarded as peraluminous crust-derived type granites to possess the typical geochemical characteristics of calc-alkaline rocks on continental margin,with enriched Si,K,Al(average value of A/CNK as 1.18),HREE,Rb,U,and Th,heavily depleted V,Cr,Co,Ni,Ti,Nb-Ta,Zr,Sr,P,and Ba,strongly negative Eu and common corundum normative(average value of C as 1.84).The εNd(t) values of the Zhangtiantang granite are-5.84 to-7.79,and t2DM values are 1.69 to 1.83 Ga,which indicates partial melting of continental-crust metamorphic sedimentary rocks during the Middle Proterozoic.The cooling history of the Zhangtiantang granitic pluton indicates that the cooling velocity of pluton was faster(about 67℃ /Ma) from zircon(158 Ma) to biotite(152 Ma),and was slower(about12℃ /Ma) from biotite(152.5 Ma) to K-feldspar(135.8 Ma).It can be deduced that the temporal gap(about 10 Ma) between the granite formmation and W-Sn mineralization in South China may be related to ordinary magma-hydrothermal processes by the variational cooling curve of the pluton.The Zhangtiantang pluton was formed in a compressive setting,with differentiation evolution and mineralization occurring in a relative relaxation setting.展开更多
Geochronological studies on the crust-derived Tianmenshan pluton were undertaken by SHRIMP zircon U-Pb dating and Ar-Ar dating of biotite,muscovite and K-feldspar,giving a petrogenetic age of 167 Ma.Owing to the closu...Geochronological studies on the crust-derived Tianmenshan pluton were undertaken by SHRIMP zircon U-Pb dating and Ar-Ar dating of biotite,muscovite and K-feldspar,giving a petrogenetic age of 167 Ma.Owing to the closure systems in different minerals,the cooling history of the pluton can be determined with an age-temperature diagram.The late hydrothermal event has been recognized,which is related probably with mineralization.In terms of the comparative geochronological and petrologic records,it is concluded that there are some constrains on tectonic evolution and that the formation of the Tianmenshan pluton proceeded in a transition period from Indosinian post-orogeny extension to strong compressive tectonics.And the timing of the hydrothermal event matches the compressive climax of the Yanshanian orogeny.The temporal gap between granite emplacement and wolframite mineralization could last 10-20 Ma owing to the low cooling rate of the pluton.展开更多
赣南牛岭钨矿床是近年新发现的典型石英脉型钨矿床。在矿床野外地质调查的基础上,本文选择矿区中细粒斑状黑云母花岗岩、含钨石英脉开展高精度测年研究,获得牛岭黑云母花岗岩LA-ICP-MS锆石U-Pb年龄为156±1 Ma(MSWD=0.94),辉钼矿Re...赣南牛岭钨矿床是近年新发现的典型石英脉型钨矿床。在矿床野外地质调查的基础上,本文选择矿区中细粒斑状黑云母花岗岩、含钨石英脉开展高精度测年研究,获得牛岭黑云母花岗岩LA-ICP-MS锆石U-Pb年龄为156±1 Ma(MSWD=0.94),辉钼矿Re-Os等时线年龄为156.8±6.3 Ma (MSWD=0.01),白云母40Ar-39Ar阶段升温坪年龄为157.2±1.0 Ma (MSWD=0.31)。上述测试结果一致表明,牛岭钨矿床成岩成矿作用均发生于晚侏罗世。辉钼矿Re/Os同位素及成矿母岩性质反映成矿金属来自于地壳。综合华南侏罗纪-白垩纪地质事件序列和动力学研究成果,认为古太平洋板块西向俯冲机制下的安第斯型陆缘弧后环境可能是矿床的理想成矿构造背景。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supported by the National Key Research and Development Program of China (grant No. 2016YFC0600203)the Natural Science Foundation of China (grants No. 41672065, 41830428,41472032)
文摘Objective The Dajishan W-Ta-Nb deposit is located in the junction of southern Jiangxi and Guangdong Provinces(Fig. 1a). This deposit contains about 190, 000 tons of WO3 reserves,belonging to a super-large W deposit. Most W mineralization (mainly wolframite) at Dajishan occurred in quartz veins, with also some disseminated wolframite in the No. 69 granite.
基金supported by the Foundation of Geology Research Projects,funded by the Department of Science and Technology and International Cooperation,Chinese Geological Survey (Grant No. 1212010611805)
文摘The zircon SHRIMP dating of the Zhangtiantang granite gave an age of 159±7 Ma.,which shows that the granite was produced at the early Late Jurassic.The Ar-Ar plateau ages of biotite and K-feldspar from the Zhangtiantang pluton are 153.2±1.1 Ma and 135.8±1.2 Ma,respectively.The Ar-Ar anti-isochrone ages of biotite and K-feldspar are 152.5±1.7Ma and 135.4±2.7Ma,respectively.The ages represent the isotopic closure ages of minerals in the pluton.The Zhangtiantang granites are regarded as peraluminous crust-derived type granites to possess the typical geochemical characteristics of calc-alkaline rocks on continental margin,with enriched Si,K,Al(average value of A/CNK as 1.18),HREE,Rb,U,and Th,heavily depleted V,Cr,Co,Ni,Ti,Nb-Ta,Zr,Sr,P,and Ba,strongly negative Eu and common corundum normative(average value of C as 1.84).The εNd(t) values of the Zhangtiantang granite are-5.84 to-7.79,and t2DM values are 1.69 to 1.83 Ga,which indicates partial melting of continental-crust metamorphic sedimentary rocks during the Middle Proterozoic.The cooling history of the Zhangtiantang granitic pluton indicates that the cooling velocity of pluton was faster(about 67℃ /Ma) from zircon(158 Ma) to biotite(152 Ma),and was slower(about12℃ /Ma) from biotite(152.5 Ma) to K-feldspar(135.8 Ma).It can be deduced that the temporal gap(about 10 Ma) between the granite formmation and W-Sn mineralization in South China may be related to ordinary magma-hydrothermal processes by the variational cooling curve of the pluton.The Zhangtiantang pluton was formed in a compressive setting,with differentiation evolution and mineralization occurring in a relative relaxation setting.
文摘Geochronological studies on the crust-derived Tianmenshan pluton were undertaken by SHRIMP zircon U-Pb dating and Ar-Ar dating of biotite,muscovite and K-feldspar,giving a petrogenetic age of 167 Ma.Owing to the closure systems in different minerals,the cooling history of the pluton can be determined with an age-temperature diagram.The late hydrothermal event has been recognized,which is related probably with mineralization.In terms of the comparative geochronological and petrologic records,it is concluded that there are some constrains on tectonic evolution and that the formation of the Tianmenshan pluton proceeded in a transition period from Indosinian post-orogeny extension to strong compressive tectonics.And the timing of the hydrothermal event matches the compressive climax of the Yanshanian orogeny.The temporal gap between granite emplacement and wolframite mineralization could last 10-20 Ma owing to the low cooling rate of the pluton.
文摘赣南牛岭钨矿床是近年新发现的典型石英脉型钨矿床。在矿床野外地质调查的基础上,本文选择矿区中细粒斑状黑云母花岗岩、含钨石英脉开展高精度测年研究,获得牛岭黑云母花岗岩LA-ICP-MS锆石U-Pb年龄为156±1 Ma(MSWD=0.94),辉钼矿Re-Os等时线年龄为156.8±6.3 Ma (MSWD=0.01),白云母40Ar-39Ar阶段升温坪年龄为157.2±1.0 Ma (MSWD=0.31)。上述测试结果一致表明,牛岭钨矿床成岩成矿作用均发生于晚侏罗世。辉钼矿Re/Os同位素及成矿母岩性质反映成矿金属来自于地壳。综合华南侏罗纪-白垩纪地质事件序列和动力学研究成果,认为古太平洋板块西向俯冲机制下的安第斯型陆缘弧后环境可能是矿床的理想成矿构造背景。
