塔里木盆地北缘日达里克地区砂岩型铀成矿控矿因素浅析

Analysis on Ore-Controlling Factors of Sandstone-type Uranium Mineralization in Ridalik Area Northern Margin of Tarim Basin

通过地质调查、钻探揭露及地球化学等找矿方法,对日达里克地区铀成矿控制因素进行分析。结果显示,南天山蚀源区及砂体本身均可提供丰富的铀源,而丰富的铀源在一定程度上弥补了成矿时间短的不利因素。目的层划分的旋回或亚旋回多为数个河流期次沉积形成,划分层间氧化带时,按河流期次进行细划分。成矿时间短,铀搬离氧化带进入过渡带时间不够,导致铀多富集在过渡带靠近氧化带一侧。各旋回原生带砂岩有机炭含量均大于0.1%,且在过渡带发生明显富集作用,是铀成矿关键控矿因素之一。

Through geological survey,drilling and geochemical data study,The controlling factors of uranium mineralization in the lower member of Kuqa Formation in Ridalic area are analyzed,Uranium sources are abundant in the erosion source area of the Southern Tianshan Mountains and in the sand body itself,This abundant uranium source to some extent compensates for the disadvantage of short mineralization time.The cycles or subcycles divided by the target strata are mostly formed by several fluvial stages of sedimentation,The sand body can be divided according to fluvial periods,especially when dividing interlayer oxidation zone.The mineralization time of the target layer in the area is short,and the time of uranium moving from the oxidation zone to the transition zone is not enough,resulting in uranium enrichment in the transition zone near the oxidation zone.The organic carbon content of sandstone in the primary zone of each cycle is more than 0.1%,and it is obviously enriched in the transition zone,The organic carbon content is one of the key factors controlling uranium enrichment.