桂西大新-钦甲地区辉绿岩脉地球化学与锆石U-Pb同位素
年代学及对碳硅泥岩型铀矿床成因的启示
宋昊1 徐争启1 宋世伟2 倪师军1 张成江1 晏文权1 程发贵3 李亚平4 【摘 要】Abstract Numerous uranium polymetallic deposits, uranium polymetallic occurrences and mineralized spots are widely distributed in western Guangxi. Daxin Sanqisan uranium ore deposit is one of the most important and famous sources of the carbonate-siliceous-pelitic rock-type uranium deposits in southwestern China, which has drawn great attention of many geological researchers and ore deposit experts for its scale, high grade, intensive distribution and abundant associated ores. Sanqisan and Bajiang U deposits and several U occurrences were selected from western Guangxi for the present study. The tectonic environment of diabase dykes is distinguished as the plate basalt (WPB) by geochemical characteristics, which draw the conclusions that the content of SiO2 in rocks has a large variation, mainly caused by silicides. SiO2 is obvious negatively correlated with Fe2O3, MgO, CaO and FeO, while alkali degree (Na2O+K2O) is poor. Trace element enriches high field strength elements Ta, Nb, Zr and Hf, and big ion lithophile elements Rb, U, Th and Ba, and losses Sr. The chondrite-normalized rare earth element (REE) patterns are light REE-enriched and exhibit no Eu anomalies. According to laser ablation LA-ICP-MS U-Pb zircon dating, the ages for the diabase dykes are 86.7±0.9Ma, 89.05±0.96Ma and
桂西大新-钦甲地区辉绿岩脉地球化学与锆石U-Pb同位素年代学及对碳
