东濮凹陷沙三段盐岩成因  

Origin of 3^(rd) Member salt rock of Shahejie Formation in Dongpu Sag

作　　者：苏惠[1] 许化政[2] 张金川[1] 曲丽萍[3] 王萍霞[3] 曾探[3] 李桂霞[3] 乔朝泽[3] 

机构地区：[1]中国地质大学 [2]中国石化石油勘探开发研究院 [3]中国石化中原油田勘探开发科学研究院

出　　处：《石油勘探与开发》2006年第5期600-605,共6页Petroleum Exploration and Development

基　　金：国家自然科学基金资助项目(40472073)

摘　　要：东濮凹陷沙三段(Es3)发育盐岩和膏盐岩,岩心观察见有冲刷面、泥裂、波痕等浅水和暴露标志,地震剖面显示有低位楔、削截面、下超等湖岸线进退现象,说明Es3沉积期古湖泊水体深度变化大。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,发育低位三角洲与扇三角洲沉积,纵向形成深湖泥岩与蒸发岩、低位砂岩的频繁互层。分析认为,盐岩为浅水成因,盐源为周边隆起的中、下奥陶统。这一认识不同于过去“高山深盆”、“深水成盐”和“海相成因”的观点,将给东濮凹陷沉积古地理、古环境研究带来新的认识。In Dongpu Sag, red sediments can be found within the salt-gypsum developed in 3^rd Member of Shahejie Formation （Es3）. Shallow water and exposed signs are also found as scour surfaces, mud cracks and ripple marks in the cores. Lakeshore on-off signs of lowstand wedge, truncation and downlap are recognized from seismic profiles. These indicate that the water depth of paleolake changed during the deposition of Es3. Deep-grey and dark mudstones and a few gravity sandbodies developed in the highstand period, while salt rock, gypsum rock, lowstand deltas and fan deltas developed in the lowstand period. As a result, deep lake mudstones are interbedded with evaporites and lowstand sandbodies. The paper argues that the salt rocks are deposited in shallow water, the salt comes from the Lower-Middle Ordovician series of the surrounding uplifts. This argument is different from the past theories of ＂high mountain deep lake＂, ＂salt deposited in deep water＂ and ＂salt deposited in marine facies＂.

关 键 词：东濮凹陷 浅水成盐 深水成盐 海侵说 陆源说 

分 类 号：TE122.2[石油与天然气工程—油气勘探]