松辽盆地白垩系青山口组黑色页岩的形成环境及海水侵入的底流模式

THE ORIGIN OF THE BLACK SHALES AND THE BOTTOM CURRENT MODEL FOR SEAWATER ENCROACHMENT IN THE CRETACEOUS QINGSHANKOU FORMATION,SONGLIAO BASIN,NORTHEAST CHINA

通过对中央坳陷区两口钻井剖面和东南隆起区野外露头剖面的沉积学、矿物学和地球化学研究，认为松辽盆地白垩系青山口组黑色页岩形成于稳定分层的湖相环境；周期性海水注入形成的底流是导致水体分层和黑色页岩沉积的重要因素。

The study of sedimentary sequences, mineralogy and geochemistry of the black shales in the Cretaceous Qingshankou Formation has revealed that the Songliao nearshore continental basin was affected by periodic transgression/regression of the adjacent marine water from the Pacific Ocean during the deposition of the Qingshankou Formation (88. 5-100 Ma).On the basis of the palaeoenvironmental analysis of the black shales, the authorsconclude that the bottom current resulted from periodic transgressions may be the mainfactor which gives rise to the stratification of lake water and the deposition of the blackshales in the study area, and a simplified model showing the marine incursions ill this areais also proposed.