华北地洼区北缘东部及邻区活化构造和铀成矿作用

该区处于欧亚东西向海西铀成矿带与环太平洋成矿带相交的有利部位。铀矿化产于地槽褶皱阶段、反射活化阶段和地洼阶段,具有铀成矿作用时间长、矿化类型多的特点。该区中新生代岩浆岩,特别是火山岩十分发育,与此相应地洼期铀成矿作用以热液型为主,特别是与火山作用有关的成矿作用具有十分重要的意义。

Tectonic Activization And Uranium Mineralization In The Eastern Part Of The North Margin Of The North China Diwa And Its Neighbouring Areas

The North China diwa region is of Cathysian type developed on the basis of the post-Luliahg orogeny whereas the Northeast China diwa region on the Jiorth is one evolved from the Post-Hercynian platform. Affected by the Caledonian-Hercynian geosynclinal folded belt to the north, the North China diwa underwent reflex activation during Paleozoic. Located at the intersection of the EW-trending Hercynian uranium metallogenic belt striding across Europe and Asia and the Circum-Pacific metallogenic belt, this region is favorable for uranium mineralization, as is evidenced by the occurrence of uranium mineralization in all the geosynclinal folding phase, reflex activation phase and diwa phase. Therefore, it is now an important uranium metallogenic region in North China characterized by prolonged uranium mineralization and numerous ore types. The evolution of the diwa phase has an important bearing on the formation of uranium deposits. The Meso-Cenozoic magmatic rocks, especially the volcallic rocks, are most developed, and the corresponding diwa phase uranium mineralization is dominated by hydrothermal type. The mineralization bound up with volcanism has great significance in particular. In North China diwa region uranium mineralization also occurred in reflex activation phase; nevertheless, unlike what happend or the southern margin of the Alxa old land, it only possesses the secondary importance.