郭春影, 李子颖, 韩军, 徐浩, 白芸, 任忠宝, 韩愉, 赵宇霆. 辽东大石桥组蛇纹石化大理岩中铀矿化特征及形成时代[J]. 地质通报, 2017, 36(4): 565-574.
    引用本文: 郭春影, 李子颖, 韩军, 徐浩, 白芸, 任忠宝, 韩愉, 赵宇霆. 辽东大石桥组蛇纹石化大理岩中铀矿化特征及形成时代[J]. 地质通报, 2017, 36(4): 565-574.
    GUO Chunying, LI Ziying, HAN Jun, XU Hao, BAI Yun, REN Zhongbao, HAN Yu, ZHAO Yuting. Geological features and dating of uraninite in serpentinized dolomite marbles of the Dashiqiao Formation in eastern Liaoning Province[J]. Geological Bulletin of China, 2017, 36(4): 565-574.
    Citation: GUO Chunying, LI Ziying, HAN Jun, XU Hao, BAI Yun, REN Zhongbao, HAN Yu, ZHAO Yuting. Geological features and dating of uraninite in serpentinized dolomite marbles of the Dashiqiao Formation in eastern Liaoning Province[J]. Geological Bulletin of China, 2017, 36(4): 565-574.

    辽东大石桥组蛇纹石化大理岩中铀矿化特征及形成时代

    Geological features and dating of uraninite in serpentinized dolomite marbles of the Dashiqiao Formation in eastern Liaoning Province

    • 摘要: 在辽东大石桥组蛇纹石化大理岩中新发现晶质铀矿矿化现象。晶质铀矿呈角砾状发育在蛇纹石化白云石大理岩中,并叠加有辉钼矿、黄铁矿等矿化。U-Pb同位素年龄测定显示,晶质铀矿形成于1763~1794Ma。EPMA U-Th-Pb化学年龄显示,晶质铀矿形成后经历了1512±20Ma的热事件改造,对应一次岩浆侵入事件。辽东地区经历了古元古代的裂谷拉张、碰撞造山、造山后伸展等重大地质事件。大石桥组中蛇纹石化大理岩中的铀矿化,以及连山关铀矿床、翁泉沟地区铁-硼-铀矿床的热液铀成矿作用均形成于古元古代晚期造山后/非造山区域伸展环境,可能与区域伸展体制下的地幔柱活动有关。

       

      Abstract: In this study, the authors analyzed the geological features and ore-forming ages of the newly found uranium mineralization in serpentinized dolomite marbles to infer their regional metallogenic significance. The uranium mineralization in serpentinized dolomite marbles occurs as uraninite breccias imprinted by later sulfide mineralization such as molybdenite, pyrite. The U-Pb isotopic dating indicates that the uraninite was formed in 1763~1794Ma. The in situ EPMA U-Th-Pb chemical dating of uraninite implies a thermal reworking event on uraninite at 1512±20Ma, which is synchronous to a regional magmatic event. The eastern Liaoning Province underwent significant geological evolution in Paleo-Proterozoic, from early rifting to collisional orogenesis and post orogenic extension. The newly found uranium mineralization in serpentinized dolomite marbles and the uranium mineralization in the Lianshan-guan U deposit and in the Fe-B-U deposits in the Wengquangou area were all formed in a post orogenic/unorogenic extensional environment possibly related to the mantle plume activity in regional extensional tectonic setting.

       

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