东濮凹陷沙三段盐岩成因及含盐地层层序划分

东濮凹陷沙三段高水位期沉积深灰色、暗色泥岩与少量重力流砂体，低水位期沉积盐岩、膏岩、低位三角洲与扇三角洲，从而形成纵向上深湖泥岩与蒸发岩、低位砂岩的频繁互层沉积。根据岩心资料、盐岩沉积序列特点及沙三段沉积期古气候和古环境特点，认为盐岩为浅水蒸发成因。深水相泥岩与浅水成因的盐岩频繁互层表明沙三段沉积期湖平面变化频繁。基于盐韵律特征划分准层序的方法，使得层序地层划分更为符合东濮凹陷含盐地层的实际情况。

The salt rock genesis of 3^rd member of Shahejie formation in Dongpu Depression and the division of saline formation sequence

In 3^rd member of Shahejie formation in Dongpu Depression, deep grey and dark mudstone and a few gravity sandbodies developed in the highstand, and in the lowstand, salt rock, gypsum rock, lowstand deltas and fan deltas developed, as a result, deep lake mudstone are interbeded with evaporite and lowstand sandbodies. According to the core data, the characteristic of salt sedimentation., palaeoclimate and palaeoenvironments, salt rock is thought to be deposited in shallow water. The black mudstone deposited in deep water interbedded with salt deposited in shallow water shows that the lake level changes frequently during the sedimentation of 3^rd member of Shahejie formation. With the method of parasequences identification based on the the characteristic of salt cadence, the sequence division is accord with the practice in saline formation in Dongpu Depression.