吐哈盆地大南湖地区层间氧化带特征及铀找矿前景

利用前人钻孔资料并结合野外调查,研究了找矿目的层西山窑组沉积环境、岩相古地理特征、砂体厚度及空间展布;对比各岩层的后生氧化程度,确定了层间氧化带的分布范围和空间展布形态。通过对目的层砂岩岩石学和岩石化学特征的研究,初步查明了本区砂岩孔隙度、密度与其结构构造密切相关,以及氧化带中次生矿物变化和化学元素如Fe、CO2、C有、S、U、Th、Se、Mo、V等含量变化与地下水的氧化作用有关,符合水成铀矿床的变化规律。在此基础上,圈定出氧化砂体,其底板埋深小于300m、厚度达50-100m、氧化带前锋长达60km。并在氧化带前锋发现铀矿化、硒矿化多处,初步显示该区具有良好的找矿前景。

The Characteristics of Interbedded Oxidated Zone and Prospect of Uranium Deposit in the Danan Lake Area, Turpan-Hami Basin

Based on former drilling data and our field investigations, writers studied the sedimentary environment, paleogeographic characteristics, sandstone bodies' thickness and spacial distribution of the Xishanyao Formation, which is the goal layer of prospect. Based on the epigenetic oxidation degrees of various layers of the Xishanyao Formation, the distribution and spacial shape of interbedded oxidation zone were ascertained. The sandstone petrological and petrochemical characteristics of the goal layer suggests that there are close relations between sandstone porosity, density and its texture-construction, and that the variations of the secondary minerals and the contents of chemical elements such as Fe, CO2, C (organic carbon), S, U, Th, Se, Mo, V et al. are closely related to the oxidizing action of groundwater, and agree with the variation rules of aqueous uranium deposit. Based on the studies above, the oxidated sand body was confined, which has the depth of bottom footwall of less than 300m and the thickness of 50-100m. The length of the oxidation zone front is up to 60 km. Many uranium mineralization and selenium mineralization points were found in the oxidation zone front. Therefore, it is suggested that the region has good prospect for the uranium deposits of sandstone-type.