新疆吐哈盆地布尔加凸起八道湾组沉积特征浅析OA

Buerjia bulge is located in western Turpan depression of Turpan-Hami Basin in Xinjiang,with the uranium rich layers Badaowan Formation of Lower Jurassic.The research focused on the geological background of uranium mineralization in Badaowan Formation,the author systematically summarized the characteristics,sedimentary facies,sand bodies,and petrological features of sandstone type uranium mineralization in Badaowan Formation for the first time through field investigation,core observation,grain size analysis,thin section identification,etc.The uranium mineralization conditions were analyzed from the aspects of uranium source,structure,paleoclimate,lithology and interlayer oxidation zone.The result suggests that Baodaowan Formation in Buerjia bulge was a set of sedimentary formation of coal-bearing clastic rock,mainly composed of braided river to braided river delta facies sedimentation,with 3-5 layers of sand bodies developed.The sand bodies are large in scale and have good connectivity,making them a favorable target uranium storage layer.The study of petrological characteristics shows that the sand bodies of Badaowan Formation are mainly composed of medium sandstone and fine sandstone,with good sorting.The detrital rocks are mainly lithic sandstone and feldspar lithic sandstone,with low rock maturity,reflecting that the study area is close to the source area and has strong hydrodynamic conditions in the river channel.Through analysis of mineralization conditions,the uranium rich rock bodies in the erosion source area were believed to provide abundant uranium sources for the formation of target uranium mineralization layer the basin.The target uranium layer then experienced the process of uplift erosion→stable sedimentation→uplift transformation which made them conducive to the development of interlayer oxidation zones,pre enrichment of uranium and further mineralization superposition.Therefore,the sandstones of braided river to braided river delta facies and clearly divided interlayer oxidation zone in Badaowan Formation is the target horizons,Buerjia bulge is the key potential area for next exploration.