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天门山震旦/寒武系界线上地外撞击事件痕迹 总被引:2,自引:0,他引:2
从湘西北天门山震旦—寒武系界线上发现的冲击砾裂、冲击角砾、冲击岩脉、微球粒撞击玻粒(microirghi-zites)、微球粒玻璃陨石(microtektites),特别是陨石碎屑残迹现象,可能表明:在震旦—寒武系界线上曾经发生过地外撞击的事件。 相似文献
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The multimetal mine described in this paper contains W, Mo, Bi, Sn, Be, Cu, Pb,Zn and etc. Deposits occur in Upper and Middle Devonian carbonatite rocks and exhibite apparent zonal arrangement around a small granite body with respect to the elements mentioned above. At least four periods of magmatic intrusion and mineralization are recognized within this distriet. A comagmatic origin is indicated for all the deposits by geological setting, mineral assemblages, the geochemistry of ore elements,isotopic compositions of lead and sulfur as well as fluid inclusion studies. Ore metals are derived chiefly from the granite while wall rocks cannot be excluded as a minor supplier. 相似文献
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天门山震旦/寒武系界线上可能撞击事件目标地层展布与分析 总被引:3,自引:1,他引:3
可能发生在中国扬子台地震旦-寒武系界线上地外撞击事件的目标地层应该是湘西北天门山震旦-寒武系界线上的Ni-Mo多金属元素富集层及其相对应的层次。文中分析了这一目标地层的展布和地质特征。这一特殊层位对于上下地层沉积环境的演变有着重要的意义。 相似文献
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