Abstract: Huge scale red beds-gypsum salt beds sediments were developed during the period of the Member 1 of Kongdian Formation(Ek1)and the lower submember of the Member 4 of Shahejie Formation(Es4x)of Paleogene in Dongying Sag，Jiyang Depression.It was recognized that red beds-gypsum salt beds sediments were characterized by the coexistence of aquatic sedimentation and subaqueous sedimentation and coexistence of gravity current sedimentation and traction current sedimentation. The vertical superposition styles of red beds-gypsum salt beds sediments are quite different at different positions of the Dongying Sag. Based on the analyses of sedimentary characteristics，grain size of clastic and vertical superposition style.According to the analyses of characteristics of geochemistry and color of mudstone and previous researches，the sedimentary environments of the period of red beds-gypsum salt beds development was dominated by dry climate and dry climate and wet climate were alternate frequently.The salinity of the lacustrine basin was relatively lower and the sediments were mainly sandstones and mudstones during the period of wet climate，while the salinity was relatively higher and the sediments were mainly gypsum salt during the period of dry climate.The lacustrine basin was a oscillatory basin with a lower water level at the early and middle periods of Ek1-Es4x and was changed to a higher water level oscillatory lacustrine basin at the late periods of Ek1-Es4x，which have different characteristics of sedimentation.

Key words: red beds, gypsum salt beds, sedimentary model, Paleogene, Dongying Sag, Jiyang Depression

摘要： 济阳坳陷东营凹陷古近系孔店组一段—沙河街组四段下亚段（Ek1-Es4x）沉积时期发育了规模巨大的红层—膏盐层沉积。通过对红层—膏盐层沉积构造、碎屑颗粒粒度和沉积物垂向叠加样式等分析，表明红层沉积具有水上沉积作用和水下沉积作用共存、重力流沉积作用与牵引流沉积作用并存的特征。红层—膏盐层在盆地的不同位置具有明显不同的垂向叠加样式。通过地球化学特征分析和泥岩颜色分析，结合前人研究表明，红层—膏盐层沉积时期沉积环境以干旱为主，呈现干湿频繁交替的特征。气候相对潮湿时期，湖盆盐度较低，以沉积砂泥岩为主；气候干旱时期，湖盆盐度高，以沉积膏盐岩为主。红层—膏盐层沉积早中期为低水位振荡性湖泊，沉积晚期为高水位振荡性湖泊，两者沉积作用存在较为明显的差别。

关键词: 红层, 膏盐层, 沉积模式, 古近系, 东营凹陷, 济阳坳陷

CLC Number: 

• P588.24+7