湘桂及其邻区裂谷与铀成矿

裂谷是地壳演化过程中一种重要的构造形式，并表现出特定的成矿地质构造环境。湘桂地区在中晚元古代以来就经历了几次地壳裂解，控制了区内多旋回地槽的发展，至广西运动才完成基底的统一，转化为相对稳定的地台区。晚古生代，由于受到古特权斯和西太平洋构造活动的影响，使广布的台地陆表海产生一系列台沟，形成了一套含火山物质的深水相沉积建造，控制了区内有关矿产的形成和富铀地层的产出，印支运动使区内海盆关闭，地壳抬升并转化为地洼区。中、新生代出现了强烈的构造一岩浆活动，以及相间出现的伸展构造盆地，是区内铀矿床形成的主要时期。

RIFTS AND URANIUM MINERALIZATION IN HUNAN-GUANGXI AND THE ADJACENT AREAS

Rift was an important tectonic pattern during the crustal evolution,and shew a particular geological tectonicenvironment for the mineralization.Since middle-late Proterozoic Era,Hunan- Guangxi provincial area experi-enced crustal breakup several times, which controlled the development of polycyclic geosynclines. The basement ofthe area was united and a relative stable platform came into existence after Caledonian Movement.In the late pa-leozoic Era,affected by the ancient Tethys and Pacific tectonic movement,a range of platform-trenches werepreduced in a widespread continental sea, and a set of deep-water facies of sedimentary formation including vol-canic material was deposited in them.They controlled the formation of the related mineral resources and the oc-currences of U- rich strata. The sea basins were closed in Indo-China Movement,and then the area was trans-ferred into Dlwa region. In the Mesozoic and Cenozoic Era,intense tectono-magmatic action occured and exten- sional tectonic-hasins appored separately. This is a significant uranium metallogenic era in the area.