库车坳陷库车组下段层间氧化带划分及铀矿找矿方向  

Interlayer Oxidation Zonation and Uranium Prospecting Direction in the Lower Member of Kuqa Formation, Kuqa Depression

作　　者：杨小强[1] 王强强[1] 王元元[1] 李书海[1] 吕俊维 YANG Xiaoqiang;WANG Qiangqiang;WANG Yuanyuan;LI Shuhai;LYU Junwei(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1期59-70,共12页Uranium Geology

基　　金：中国核工业地质局项目(编号:202108-1、201907-1、201907-2、201907-4);塔里木盆地项目(编号:HTLM2101)联合资助。

摘　　要：库车坳陷位处于塔里木盆地北缘,具有良好铀成矿背景,库车组下段中赋存有较好铀矿化信息,但对其成因类型仍存在争议。文章通过野外调查及样品统计分析,对库车组下段中粗碎屑岩开展岩石地球化学特征研究,分析其铀矿成因,并进行层间氧化带划分。结果表明,库车坳陷库车组下段具有明显的水平分带特征,自盆山结合部位向盆地方向可划分为原生氧化环境的冲洪积粗碎屑沉积物,后生氧化成因的褐红色砂-砾岩、灰白色砂-砾岩、褐黄色砂-含砾砂岩、浅黄色砂岩,及原生的灰色砂-含砾砂岩,反映铀矿成因为层间氧化带型,进而将库车组下段层间氧化带划分为氧化带、过渡带、原生带,各分带地球化学指标与典型层间氧化带型砂岩型铀矿床一致。库车坳陷库车组下段砂岩型铀矿找矿方向:西段以氧化带为线索垂直层间氧化带发育方向探索其含矿性;中段在日达里克地段扩大已有或找寻新的矿(化)带,在墩买里、温巴什地段在可探范围内探索层间氧化带前锋位置;东段继续区域调查。Kuqa depression was believed favorable in uranium metallogenic background with favorable mineralization information in the lower member of Kuqa Formation. However, the genetic type of uranium mineralization is in controversial. In this paper, the lithogeochemical characteristics of middle coarse clastic rocks in the lower member of Kuqa Formation was studied with field investigation and samples analysis, and the genesis of uranium deposit was analyzed with alteration zonation. The study showed that there is obvious horizontal alteration in Kuqa Formation. From the joint area of the mountain-basin to the center of the basin, the lithogeochemical feature of rock can be divided into three types: the original oxidation of pluvial coarse sediments, the epigenetic oxidation of maroon sanstone-conglomerate, gray sandstone-conglomerate, brown yellow gravelly sandstone, yellowish sandstone, and original conductive gray sandstone-gravelly sandstone, and the uranium mineralization was therefore believed to be interlayer oxidation zone type. The interlayer oxidation zone of the lower member of Kuqa Formation can be divided into oxidation zone, transition zone and reductive zone. The geochemical indexes of each zone are consistent with typical interlayer oxidation zone sandstone-type uranium deposit. In the west section, the next uranium exploration should focus on the uranium grade vertical to the interlayer oxidation front. In the middle section of Zhidarik, the next uranium exploration should pay attention to expand the discovered mineralization belt, especially the front of interlayer oxidation in the Tunmaili and Wumbashi sections. In the east section, regional survey should be conducted continually..

关 键 词：岩性地球化学类型 层间氧化带 找矿方向 库车组 库车坳陷 

分 类 号：P619.14[天文地球—矿床学]