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库车坳陷中生代呈北陡南缓的箕状，其内连续沉积了一套厚度巨大的冲积—湖泊碎屑沉积体。湖缘扇三角洲、辫状河三角洲及曲流河三角洲非常发育，它们的特征清楚、区别明显：（１） 扇三角洲为突发的、瞬时的灾变事件产生的重力流沉积与间灾变期正常牵引流沉积交替进行，并以重力流沉积占主导地位：其平原亚相类似于冲积扇沉积，河道砂体呈透镜状，厚度小、变化大。（２） 辫状河三角洲为正常的河流牵引流沉积，通常受到湍急洪水控制，为季节性沉积作用产物；平原亚相类似于辫状河沉积；河道沉积发育，砂体总体呈层状，内部由若干个下粗上细的河道砂岩透镜体相互叠置而成，交错层发育，尤以侧积交错层异常发育为特征，岩性以颗粒支撑的砂砾岩为主。（３） 曲流河三角洲为正常的河流牵引流沉积，沉积物输入量为相对连续的终年河流的产物，平原亚相类似于曲流河沉积：河道砂体呈层状，交错层发育，类型丰富。当然，这三种类型三角洲之间亦存在着密不可分的内在联系，不仅同一时期内可以并存，而且随着地质历史的演化可相互转化。
The Mesozoic Kuqa Depression was a gently north-steeply graze-like sediment, in which a set of thick alluvial-lacustrine sediments were continuously deposited. The lacustrine fan delta, braided river delta and meandering river delta are well developed. Their characteristics are distinct and distinct: (1) the fan delta is a sudden, transient catastrophic event with gravity flow deposition and catastrophic normal traction The flow deposition alternated and dominated by gravity flow deposition: its plain subfacies were similar to alluvial fan sediments, and the channel sand bodies were lenticular with small thickness and large variation. (2) The braided river delta is a normal river flow and is generally controlled by the turbulent flood and is a seasonal sedimentary product. The plains are similar to the braided river sediments. The river sediments are developed and the sand bodies are generally layered. The interior It is composed of a number of finely tuped fluvial sandstone lenses superimposed on one another, with alternating layers developed, especially with abnormally developed lateral-intercalated layers. The lithology is mainly composed of grain-supported glutenite. (3) The Meandering Delta is a normal river flow sediment deposition. Sediment input is the product of a relatively continuous stream of year-round rivers. The plain subfacies are similar to meandering river sediments. The river sand bodies are stratified, rich. Of course, there is also an inseparable relationship between the three types of delta. They can coexist not only during the same period but also with the evolution of geological history.