Based on the observation and statistics on the calcareous sandstone in the ore host layer in shihongtan uranium deposit , this paper finds that the calcareous sandstone occurs on and off near the top or wash surface of the sandbody as beads - strings lens along the layer and concentres in the area where the orebodies are rich 摘要通过对十红滩铀矿床容矿层钙质砂岩的观察和统计，发现钙质砂岩呈顺层、断续的串珠状透镜体分布，产出空间位置为砂体的顶底部或冲刷面，而且较集中的分布在矿体发育区。
The early coaxial progressive depressing makes the forming of tectonic lens in the competent rich - sodic and incompetent rich - mud rocks ; the later nocoaxial progressive shearing makes the tectonic compression fracture into extension fracture in the early tectonic lens , at the same time , the great drop of pressure leads to the hydrofractureing of deep fluid along the fracture in the rich - sodic rocks , and then produces the hydrofracturing breccia 早期共轴递进挤压使能干性的富钠质岩系与非能干性的富泥质岩系发生构造透镜石香肠化；晚期的非共轴递进剪切使早期在透镜体中心形成的构造裂隙由剪性转化?张性，并?生巨大的压力降使深部的流体在富钠质岩系中沿裂隙发生水力压裂作用，从而形成双王水力压裂含角砾岩。
By the types of oil or gas reservoirs , three kinds of oil or gas accumulation models fit to wuerxun depression . they are the model of oil or gas migrating and accumulating in sandstone lens or fracture traps of source rock , the model of oil or gas accumulating in fault - block or fault - screened traps through vertical migration , the model of oil or gas accumulating in structural - lithological traps migrating laterally in short instance through sandrock 在此基础上，根据油气藏类型总结出乌尔逊凹陷南二段油气成藏模式有源内砂岩透镜体或裂缝圈闭油气运聚成藏模式油气沿断裂垂向运移于断块或断层遮挡圈闭成藏模式油气沿砂体短距离侧向运移于构造?岩性圈闭油气藏模式。
Near the faulty step - break , low stand system developed , and some sediment system distribute broad , such as alluvial fan , low stand wedge , low stand fan , and so on . the sand body can form not only the trap of dying out upward and sand lens , but also fault - iithology trap . the study shows that fault - lithology trap is most important trap style in study area especially sha - 3 formation 断阶坡折附近是低水位体系域发育的重要场所，常发育冲积扇、冲蚀作用的下切河道以及低水位楔状体、低水位扇体等沉积体系，这些砂体不仅具有形成上倾尖灭或砂岩透镜体圈闭的条件，而且可形成断层?岩性圈闭。
