华南诸广山岩体中段岩脉40Ar-39Ar年龄及与铀成矿关系  

40Ar-39Ar age of the late stage veins in central Zhuguangshan pluton of South China and its relationship with uranium metallogenesis

作　　者：蒋红安 邹明亮 欧阳平宁 王前林 李杰 颜越 JIANG Hongan;ZOU Mingliang;OUYANG Pingning;WANG Qianlin;LI Jie;YAN Yue(Changsha Uranium Geology Research Institute,CNNC,Changsha 410011,Hunan,China)

机构地区：[1]核工业二三○研究所,湖南长沙410011

出　　处：《地质通报》2020年第5期728-734,共7页Geological Bulletin of China

基　　金：中国核工业集团有限公司项目(编号:LTD1602、3210402);国家重点研发计划《深地资源勘查开采》(编号:2017YFC0602600)。

摘　　要：诸广山岩体中段鹿井地区矿床周边常有花岗斑岩脉及煌斑岩脉等晚期岩脉产出。钾长石40Ar-39Ar同位素年代学测试结果表明,花岗斑岩脉与煌斑岩脉侵位年龄分别为116.24±0.49 Ma和128.27±0.86 Ma,是早白垩世地壳伸展的岩浆响应。岩脉记录的岩浆活动时代与鹿井矿田铀成矿作用时代具有较好的对应关系。花岗斑岩脉与铀矿石均具有幔源特征,表明以花岗斑岩为代表的酸性岩浆在为铀矿化提供热源的同时可能还提供了部分成矿物质。在铀成矿作用过程中,以煌斑岩为代表的基性岩浆为铀成矿作用提供了热源、矿化剂、流体及动力条件等有利条件。Late stage dykes like granite porphyry and lamprophyre veins are common around the ore deposits in Lujing area,the central section of Zhuguangshan pluton.K-feldspar 40Ar-39Ar isotope geochronologic analysis indicates that the granite porphyry vein was formed at 116.24±0.49 Ma while the lamprophyre vein intruded at 128.27±0.86 Ma,indicating that their intrusion corresponded to crustal extension magmatism during the Early Cretaceous.The magmatic chronologies recorded by the dykes are consistent with the uranium mineralization age of the Lujing orefield.Both the granite porphyry vein and the uranium ore present the characteristics of mantle source,indicating that the acidic magma source of the former one might have provided not only metallogenic materials but also heat source for uranium mineralization.During the process of uranium mineralization,the basic magma source of the lamprophyre provided favorable conditions such as heat generation,mineralizer,fluid and dynamic conditions for uranium mineralization.

关 键 词：40AR-39AR年龄 铀成矿作用 鹿井地区 花岗斑岩脉 煌斑岩脉 华南 

分 类 号：P597.3[天文地球—地球化学] P619.14[天文地球—地质学]