鄂尔多斯盆地是我国陆上最主要的油气盆地之一，三叠系延长组是该盆地的主要含油层位.通过对延长组典型露头的考察与研究，结合古生物及岩性岩相资料，取得了3点新认识：（1）恢复了延长组沉积时期的古气候环境，认为其具有三分性，其中早期拉丁期为干旱环境；中期受卡尼期梅雨事件（CPE）影响气候发生突变，转变为温暖潮湿气候环境；晚期诺利‒瑞替期再次转变为半干旱‒半湿润气候环境. （2）CPE事件改变了延长组沉积物搬运与沉积方式，其中CPE事件之前与事件之后的干旱环境时期，主要发育暴雨洪水引发的季节性河流、决口扇、决口河道沉积；CPE事件当中及卡尼中期，陆源碎屑物质主要通过异重流、浊流及砂质碎屑流等多种途径搬运至水下环境，形成富砂质重力流事件沉积，同时受CPE事件控制，在深水环境还发育了黑色富有机质页岩事件沉积.（3）建立了延长组干旱与潮湿两种环境沉积模式，干旱环境湖泊水域面积较小，主要沉积单元为洪泛平原、季节性河道及决口扇，主要沉积方式为填平补齐、加积式沉积，不发育前积沉积现象；潮湿环境湖泊水域面积较大，发育完整的陆相河流‒三角洲‒湖泊‒重力流沉积体系，由于具有稳定的长流水，河道相对固定，加之受湖平面变化控制，其沉积方式以前积作用为主.该认识不仅对于深入探讨鄂尔多斯延长组大型坳陷湖盆形成演化机理、沉积层序充填演化及指导油气勘探实践有积极意义，而且对揭示晚三叠世全球极端气候事件在内陆湖盆的沉积学记录有积极意义，可以填补CPE事件在古特提斯东缘泛大陆内部沉积响应研究的空白.

The Ordos Basin is one of the main petroliferous basins in China. The Triassic Yanchang Formation is the main oil-bearing units in this basin. Based on the investigation and study of typical outcrops of Yanchang Formation and the data of paleontology, lithology and lithofacies, three new insights are obtained. (1) The paleoclimatic environment of Yanchang Formation during the sedimentary period has been recovered, which is considered to be tripartite, and the Ladinian Age was an arid environment. During the Carnian Age, the climate changed to a warm and humid environment because of the Carnian Pluvial Episode (CPE). In the Norian-Rhaetian ages, the climate environment changed to semi-arid and sub-humid again. (2) The CPE changed the way of sediment transport and deposition in the Yanchang Formation. In the dry environment period before and after the CPE, the seasonal river, crevasse splay and crevasse channels caused by rainstorm and flood were mainly developed. During the CPE and in the mid-Carnian period, terrigenous detrital materials were transported to the underwater environment mainly by various gravity flows such as turbidity flow, sandy debris flow and hyperpycnal flow, forming sandy event deposits. At the same time, controlled by the CPE, black organic-rich shale event deposits were also developed in the deep water environment. (3) Two sedimentary models of arid and humid environments were established in the Yanchang Formation. In the former, the catchment area in the arid environment was small, and the main sedimentary units were flood plain, seasonal channel, crevasse splay, crevasse channels and so on. In the latter, the catchment area of the humid environment is large, and the complete continental fluvial, delta-lacustrine and gravity flow sedimentary system is developed. Due to the stable long-flowing water, the channel is relatively fixed, the sedimentation mode is mainly progradation, supplemented by retrogradation, and not obvious aggradation. The study is of practical value to the discussion of how the large depressed lake basin formed and evolved in the Yanchang Formation, sedimentary sequence evolution, and petroleum exploration, and it is also significant to the study of the sedimentological records in inland lake basins generated by global extreme climate events in the Late Triassic Epoch to understand the sedimentary responses of the Carnian Pluvial Episode in the Pangea at the east margin of the Paleo-Tethys.