热液型铀矿空间定位的控制因素

通过对华南热液型铀矿与区域断裂构造、区域岩浆岩的时空关系、成因联系进行综合分析,笔者认为,中新生代断陷红色碎屑沉积盆地(简称断陷红盆)的控盆深源断裂构造、多期多阶段富铀岩浆活动中心联合控制了铀矿田的空间定位。铀成矿与晚白垩世区域拉张作用时间相耦合,区域铀成矿作用主要发生在晚白垩世,与导致断陷红盆形成的控盆深源断裂构造关系密切,控盆深源断裂构造为铀矿区域控矿构造。铀成矿与中生代多期富铀岩浆岩(火山岩和花岗岩)关系密切,富铀岩浆活动中心指示深部地壳存在铀的高场;来源于地幔的流体交代富铀地壳及岩浆岩,形成铀成矿流体,而富铀岩浆岩则成为热液型铀矿的主要围岩。

Controlling Factors for the Spatial Positioning of Hydrothermal Uranium Orefield

Based on a comprehensive study on the spatial,temporal and genetic relationship between hy-drothermal uranium ore field and regional faults,regional magmatic rocks in south China,it was consid-ered that uranium ore fields are spatially controlled by the deep-large basin-controlling faults which were formed during Meso-Cenozoic and the multi-stage magmatic centers with rich uranium.Regional uranium mineralization was mainly formed in the Late Cretaceous which was consistent with the time of regional tension.As the regional ore-controlling faults, deep-large faults give rise to the formation of down-faulted basins and have a close relationship with uranium mineralization.Uranium mineralization is closely related to multi-stage magmatism with uranium-rich rocks (volcanic and granitic rocks)formed in Mesozoic.Uranium-rich magmatism centers suggest that there may exist uranium-rich fields in the deep crust.Metasomatism of mantle-derived fluid to the uranium-rich crust formed the metallogenic fluids and finally acted as the wall rock (mainly uranium-rich magmatic rocks)for the hydrothermal ura-nium deposit.