渤海湾盆地东濮凹陷古近系沙河街组层序地层

Sequence stratigraphy of the Paleogene Shahejie Formation in Dongpu Sag,Bohai Bay Basin

高红灿 郑荣才 陈发亮 韩福民 刘云

Gao Hongcan Zheng Rongcai Chen Faliang Han Fumin Liu Yun

通过对研究区300多口钻井的地层对比和3000多米岩心的详细观察及区域构造-沉积演化分析,综合运用构造、古生物、岩性、地质年代以及测井和地震反射等6个方面的特征,将东濮凹陷古近系划分为3个超长期层序,分别对应于沙河街组四段下亚段、沙河街组四段上亚段-沙河街组三段、沙河街组二段-东营组;并将沙河街组四段上亚段-沙河街组一段划分为4个长期层序,分别对应于沙河街组四段上亚段-沙河街组三段四亚段、沙河街组三段三亚段、沙河街组三段二亚段-沙河街组三段一亚段、沙河街组二段-沙河街组一段。提出同一套连续沉积的盐岩在长期及超长期层序划分中具不可分割性,并结合东濮凹陷及渤海湾盆地层序划分的实例,指出目前普遍存在的层序地层划分方案与岩石地层划分方案相一致的现象值得商榷。

Based on stratigraphical correlation of over 300 wells,detailed core description of more than 3 000 m,and analysis of regional tectonic-sedimentary evolution,we divided the Paleogene in Dongpu Sag into three super long-term sequences according to various data such as tectonic geology,paleontology,lithology,geochronology,logging and seismic reflection,etc.The three sequences corresponds to the lower 4 member of Shahejie Formation,the upper 4 member to the 3 member of the Shahejie Formation,the 2 member of Shahejie Formation to the Dongying Formation respectively.Furthermore,strata from the upper 4 member to the 1 member of Sh- ahejie Formation is divided into four long-term sequences,corresponding to the upper 4 member to the 4 sub-member of the 3 member,the 3 sub-member of the 3 member, the 1 to the 2 sub-member of the 3 member and the 1 to the 2 member of Shahejie Formation respectively.This paper indicates that a set of continuous salt deposits is undividable when dividing the super long-term and long-term sequence.Taking the Dongpu Sag and Bohai Bay Basin as examples,we pointed that the common practice of making sequence stratigraphic class- ification scheme consistent with lithostratigraphic classification scheme is possibly incorrect.

10.11743/ogg20110605