摘要
赣杭铀成矿带中段分布有大量的火山岩,不同地区的火山岩在岩石地球化学特征方面存在很多共性,文章通过对带内火山岩主微量、稀土元素分析,总结岩相学、地球化学特征及其与铀成矿的关系。研究表明:火山岩属于酸性-中酸性岩石,亚碱性岩石系列,具有钾玄岩系列岩石特征,属于强过铝质岩石;微量元素特征反映了其为地壳部分熔融的产物,铀元素含量均高出地壳平均含量;稀土总量高,属于轻稀土富集、铕亏损型。赣杭铀成矿带中段火山岩具有一致的稀土元素球粒陨石标准化配分模式图,表现出不同地区的岩浆岩具有同源性。赣杭铀成矿带中段铀矿化均赋存在不同产状的火山岩中,且为铀成矿提供部分铀源。火山岩形成于碰撞后拉张伸展构造环境,且火山岩具有同源(壳源)、同期(早白垩世)特征。而成矿和成岩存在矿岩时差,成岩在前,成矿发生在成岩后期,成矿物质则可能来自幔源。
There are a lot of volcanic rocks in the middle part of Ganhang uranium mineralization belt,and the volcanic rocks in different areas have many common characteristics in petro-geochemistry.Through the analysis of the main,trace and rare earth elements of the volcanic rocks in the belt,this paper summarized the petrographic and geochemical characteristics of the volcanic rocks in the belt and analyzed their relationship with uranium mineralization.The results showed that the volcanic rocks are acid to medium-acid,fall into subalkaline to potassic basalt series with the characteristic of strong peraluminous rocks.The trace element characteristics reflect that it was the product of partial melting of the crust,and the uranium content is higher than the average content of the crust.The total amount of rare earth is high,which belongs to the type of light rare earth enrichment and europium deficit.The volcanic rocks in the middle uranium mineralization belt of Ganhang have the same standard partition pattern of chondrite normalized REE,which suggest that the magmatic rocks in different areas are from the same source.Volcanic rocks with different occurrence in the middle of Ganhang uranium metallogenic belt provide some uranium sources for uranium mineralization.The volcanic rocks were formed in extensional environment after tectonic collision and have the characteristics of homology(shell source)and contemporaneity(early Cretaceous).The mineralization and diagenesis are different in time and the metallogenic material may come from the mantle source.
作者
郑师雄
朱建林
昝芳
李栋
ZHENG Shixiong;ZHU Jianlin;ZAN Fang;LI Dong(Jiangxi Provincial Geological Bureau of Nuclear Industry 265 Brigade,Yingtan,Jiangxi 335001,China)
出处
《铀矿地质》
CAS
CSCD
2020年第6期510-519,共10页
Uranium Geology
基金
江西省核工业地质局发展引导资金项目“赣杭构造火山岩成矿带中段及重要成矿区铀矿地质数据库建设”(编号:2019SJK04)资助。
关键词
岩石地球化学
火山岩
铀成矿
赣杭带中段
petrogeochemistry
volcanic rock
uranium mineralization
middle section of Ganhang belt