松辽盆地南部西斜坡区青一+ 青二段砂体较为发育，为了研究其形成机制与分布规律，运用高分辨率层序地层学原理和方法，综合岩心、钻井、测井、地震等资料，确定了研究区层序界面的识别标志。该区 青一+ 青二段发育一个长期基准面旋回，根据该旋回内部发育的转换面，进一步将其划分为3 个中期基准面旋回。中期和长期基准面旋回的叠加样式特征明显，中期基准面旋回一般具有对称性特征，上升与下 降半旋回均比较发育；长期基准面旋回具有不对称性特征，以发育上升半旋回为主，构成“上升不对称”型 旋回结构。结果表明：研究区沉积相类型及砂体的展布受基准面变化的控制较明显，斜坡坡折带上部为三 角洲前缘发育区，下部的凹陷区主要为半深湖泥质与滑塌浊积扇体发育区；下降半旋回部分主要发育三 角洲前缘砂体，上升半旋回部分主要发育三角洲前缘砂体和浊积体。该研究成果对于研究区的油气勘探，特别是岩性油气藏的勘探，具有一定的借鉴作用。

In order to study the formation mechanism and distribution of the sand bodies developed in Qing 1 and Qing 2 members of Upper Cretaceous in Songliao Basin, with the application of the principle of high resolution sequence stratigraphy, sequence boundary marks were determined and a kind of sequence boundaries of shift surface of deposition were identified according to core, drilling/logging and seismic data. According to the research of sequence boundaries, one long-term base level cycle and three medium-term base level cycles were recognized in the target formations. Based on stacking modes of medium-term to long-term base-level cycles, the stratum mode of medium-term base level cycles is symmetry, but the stratum mode of long-term base level cycles is mainly composed of rising half cycle which composed rising asymmetry cycle configuration. Sedimentary facies and the distribution of sand bodies are mainly controlled by the change of base level. The delta front sand bodies are distributed in the rising and falling stage of medium-term base level cycles, and the turbidity sand bodies are only distributed in the rising stage of medium-term base level cycles. This understanding will be favorable for oil and gas exploration in the study area.