新疆日达里克地区后生蚀变发育方向及其对铀矿化的控制  

Distribution Characteristics of the Epigenetic Alteration Zonation and Its Control on Uranium Mineralization in Ridarik Area

作　　者：李书海[1] 鲁克改[1] 王强强[1] 王元元[1] 孙飞 党龙[1] 善曹特 LI Shuhai;LU Kegai;WANG Qiangqiang;WANG Yuanyuan;SUN Fei;DANG Long;SHAN Caote(Geologic Party No.216,CNNC,Urumqi,Xinjiang 830011,China)

机构地区：[1]核工业二一六大队,新疆乌鲁木齐830011

出　　处：《铀矿地质》2023年第4期630-641,共12页Uranium Geology

基　　金：中国核工业地质局地勘费项目(编号:202207、201907);塔里木盆地项目(编号:HTLM2101)联合资助。

摘　　要：目前在日达里克研究区地表露头及钻孔岩心中均发现了氧化砂体及受层间氧化控制的铀矿化及铀异常,具备寻找砂岩型铀矿的条件。但是,由于该区构造复杂,导致层间氧化带展布及发育方向存在一定争议,从而影响铀矿勘查工作。文章拟通过对库车组下段砂岩后生蚀变分带及地球化学特征研究,结合区内构造发育情况,探讨层间氧化带发育方向,从而进一步判断矿体赋存位置。分析研究显示,自北西向南东,依次识别出了强氧化带、弱氧化带、过渡带及原生带,各蚀变分带地球化学特征显示,氧化带具有低硫、低C有、低铀、高Fe3+含量特征,Th/U值多大于2;过渡带在地球化学障作用下,硫、C有、铀及铁元素含量最高,Th/U值较多小于0.5;还原带Th/U值接近于1,C有、硫含量介于氧化带与过渡带之间。这一特征与典型层间氧化蚀变分带相似。由此可以判断层间氧化带发育方向自北西向南东方向,结合日达里克所处构造位置及地表出露岩性特征,推断了铀矿体的大致赋存位置。At present,oxidized sandstone bodies,uranium mineralization and uranium anomalies controlled by the interlayer oxidation have been found in the outcrops and drilling cores of the Ridalike region,indicating the conditions for finding sandstone-type uranium deposits.However,due to the complex geological structure and fracture,the distribution and development direction of the interlayer oxidation zone are controversial,which affects the uranium exploration work.In this paper,the development direction of the interlayer oxidation zone was discussed by analyzing the epigenetic alteration zonation and geochemical characteristics of the lower member of the Kuqa formation sandstone,combined with the structural conditions in the area,then determine the location of the ore body.Through analysis and research,strong oxidation zone,weak oxidation zone,transition zone and primary zone were identified successively from the northwest to the southeast,and the geochemical characteristics of each alteration zone were also recognized.The oxidation zone is characterized by low sulfur,low organic carbon,low uranium and high Fe3+content with Th/U ratios mostly over 2.In the transition zone,the contents of sulfur,organic carbon,uranium and iron are the highest and the Th/U ratio is much less than 0.5;In the reduction zone,the Th/U ratio is close to 1,and the content of the organic carbon and sulfur is between the oxidation zone and the transition zone.According to the above recognition,it was judged that the development direction of the interlayer oxidation zone was from the northwest to the southeast,and the approximate location of the ore body was inferred accordingly with the structural position and the exposed lithological characteristics of the surface.

关 键 词：砂岩型铀矿 塔里木盆地 地球化学 层间氧化带 

分 类 号：P619.14[天文地球—矿床学]