柯坪露头区早志留世三角洲及碎屑海岸沉积

摘要

The outcrops of Keping area in Tarim basin.where the lower Silurian depositional sequence is continuous and perfectly exposed, constitute a preferable study area for marine clastic deposition. However, depositional system types of the lower Silurian sediments deserve further discussion. Based on detailed outcrop observation and laboratory tests, the authors analyzed the lower Silurian depositional system types and their characteristics in Keping area. As a result, deltas and clastic coast systems composed of tidal flat and offshore were detected, and river-dominated deltas and tide-influenced deltas were recognized from the Lower Silurian strata in Keping area. Large scale river-dominated delta systems are developed in Kepingtage Formation, whereas tide - influenced delta systems and tidal flat systems are developed in Tataertage Formation. On such a basis, the depositional characteristics and differences of various depositional systems are studied and compared with each other.%塔里木盆地阿克苏市柯坪露头区下志留统地层出露连续、完整,是较好的海相碎屑岩沉积露头研究区,其沉积体系类型有待进一步探讨.笔者通过多次精细的露头沉积学观察及室内研究,对柯坪露头区下志留统海相碎屑岩沉积体系类型及其特征进行了分析研究.识别出三角洲及碎屑海岸沉积(潮坪),并在该区提出了河流作用为主的三角洲和潮汐影响三角洲两种三角洲类型.柯坪塔格组主要为河流作用为主的三角洲沉积,而塔塔埃尔塔格组则主要发育潮汐影响三角洲及潮坪沉积.探讨和对比了各类型沉积体系的沉积特征及其之间的差异性.