本文建立了一种干旱背景下坳陷湖盆全新的沉积充填模式,即“洪水—河漫湖”沉积模式。在干旱背景下,物源区的河流主要表现为季节性的洪水,大多数河流都消失在荒漠中,河水主要以地表蒸发、植被生态消耗、地下渗流、河流终端湖以及河漫湖等形式排泄,坳陷湖盆内并未形成统一大面积的汇水中心和湖相沉积。这种背景条件下,湖盆的沉积充填特征明显不同于经典的坳陷湖盆和浅水湖盆沉积。下白垩统泉头组四段沉积时期,松辽盆地具有气候干旱、地势平坦、生物单调贫乏等特征,盆地南部存在5大沉积体系及7条主要的水系。除在盆地西部古龙凹陷地区河流汇水形成小范围浅水湖泊外,在盆地南部主要为“洪水—河漫湖”的河流相沉积。坳陷湖盆“洪水—河漫湖”沉积具有以下特点:①全盆地没有统一的汇水中心,因而缺乏大面积分布的湖相和三角洲沉积;②河流表现为季节性的洪水,部分河流由于地形变缓,并未进入汇水中心,而是消失在荒漠中,河流相为盆地沉积充填的主要类型;③湖盆具有多物源、多漫湖、满盆含砂的沉积特点;④河漫湖与河流在空间分布上存在3种关系,即河流终止于河漫湖、河流穿过河漫湖、河流绕过河漫湖等。坳陷湖盆“洪水—河漫湖”是一种中—新生代陆相坳陷湖盆沉积充填的新模式,具有重要的理论和实践意义。 In this paper, we set up a new sedimentary filling model of the depression lacustrine basin under the background of drought, that is, the “flood-diffuse lake” sedimentary model. In the drought context, the rivers in the provenance area are mainly seasonal floods, most of which disappear into the desert. The river water is mainly discharged in the form of surface evaporation, vegetation ecological consumption, underground seepage, river terminal lake and river Man Lake, Depression lake basin does not form a unified large-scale catchment center and lacustrine deposits. Under these background conditions, the sedimentary filling characteristics of the lake basins are obviously different from those of the classic depressions and shallow lacustrine basins. During the deposition of the fourth member of the Lower Cretaceous Quantou Formation, the Songliao Basin is characterized by arid climate, flat terrain and poor monotonous biology. There are 5 sedimentary systems and 7 major water systems in the south of the basin. In addition to the river catchment in the Gulong Sag in the western part of the basin, small-scale shallow lakes are formed. In the southern part of the basin, the river facies is mainly “flood-flood plain”. Depression lacustrine basin has the following characteristics: ① There is no uniform catchment center in the whole basin, which lacks the lacustrine and delta deposits over large area; ②The rivers show seasonal floods, and some rivers Due to the slow terrain, it did not enter the catchment center, but disappeared in the desert, and the river facies was the main type of sedimentary filling in the basin. (3) The lacustrine sediments have multi-provenance, Manchu and rivers in the spatial distribution of the existence of three kinds of relations, that is, the river ends in the river Manchu, the river through the river Manchu, the river around the river Manmo and so on. Depression lacustrine basin “Flood - River Manhu” is a new pattern of sedimentary filling of mid-Cenozoic continental depression lacustrine basin, which has important theoretical and practical significance.