根据天山南麓露头剖面和钻井层序地层研究,结合地震资料分析,将塔里木盆地喀什北地区白垩系划分为2个巨旋回层序、4个超长期旋回层序和8个长期旋回层序.其层序-岩相古地理特征自下而上表现为海平面持续上升过程中,由陆相河-湖三角洲过渡到海相三角洲,再到局限台地的沉积相变.利用泥岩微量元素分析,确定古特提斯洋在下白垩统克孜勒苏群上亚旋回就已经影响到喀什北地区,在海侵过程中,形成了连片叠置的退积型三角洲前缘沉积,并造成了该段砂岩中富含碳酸盐胶结物.下白垩统上亚旋回厚层砂岩与上白垩统及古近系的膏泥岩层构成良好的储盖组合,是喀什北地区最重要的油气储集层.%Based on the outcrop section and drilling sequence stratigraphy in the southern of Tianshan, combined with the seismic data, Cretaceous in northern Kashi area of Tarim Basin could be divided into 2 mega-cycle sequences, 4 super long-term cycle sequences and 8 long-term cycle sequences. The sequence-lithology palaeogeography characteristic was that the sedimentary facies varied from continentally fluvial-lacustrine delta to marine delta, and then to restricted platform from bottom to top during the constant sea level ascending period. According to the mudstone microelement analysis, it was considered that the northern Kashi area was affected by Paleo-Tethys Ocean at upper Kezilsu Group sub-cycle of lower Cretaceous; during the transgression process, linked and overlain regressive delta-front deposit was formed with rich carbonate cement in the sand interval. The thick sandstone sub-cycle at the upper part of lower Cretaceous and the gypsum mudstone in upper Cretaceous and Paleogene formed favourable reservoir caprock assemblage, which was considered as the most important hydrocarbon reservoir in northern Kashi area.
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