粤东罗浮岩体北部铀成矿条件分析

Analysis on Metallogenic Conditions of Northern Luofu Pluton in the East of Guangdong

罗浮岩体位于南岭成矿带东段与武夷山成矿带南段交接复合部位,是华南地区重要的产铀岩体之一。岩浆活动受东江-咸水和大塘-鹧鸪隆新华夏系断裂控制,具多期多阶段性,其中以燕山期活动最为强烈,形成北北东-北东向展布的复式花岗岩体。岩性以燕山早期第三阶段斑状黑云母花岗岩为主,岩石铀含量高,Th/U值低,有丰富的铀源条件;所处的咸水断陷带构造环境好,与大桥铀矿床具有相似的铀成矿有利条件;近年来开展的物化探工作也显示该区存在多个与北东向断裂带有关的能谱U、Rn和铀分量复合异常区。因此,认为罗浮岩体北部具有较好的铀成矿条件和找矿潜力,是今后粤东开展花岗岩型铀矿找矿的重点地段之一。

Luofu pluton is located in the junction of eastern Nanling metallogenic belt and southern Wuyishan metallogenic belt,one of the major uranium producer in southern China,Magmatism in this area is controlled by the East River-Xianshui and Datang-Zhegu Long fault.The magmatism is of multi-stage,and the most intense activity occurred in Yanshan period which formed a NNE-NE trending complex pluton.The main rock is medium coarse grained porphyritic biotite granite of the third stage in early Yanshanian.The biotite granite is of higher uranium content,low Th/U ratio.The granite complex is located in a favorable tectonic setting similar to Daqiao uranium deposits.Geophysical and geochemical exploration in recent year indicated that there existed the compound anomaly of spectrum U,Rn and partial extracted uranium with the granite complex,therefore there is favorable prospecting potential in the northern Luofu pluton of Guangdong province.