Development Features Of Paleogene Shahejie Formation And Sedimentary Facies In Caoqiao Area

Caoqiao area is located in eastern part of south slope of Dongying Sag, controlled by frequent crustal movement and long-term paleo-uplift. Stratigraphy of Paleogene Shahejie formation of this area denudate frequently and Litho-electric characteristics is not obvious. Both sides of Shicun fault affected by Shicun fault have greater difference. It is difficult to grasp the law of stratigraphic development. The question of which several groups of Shahejie formation have developed in the end has not been resolved. Predecessors have never studied sedimentary facies based on stratigraphic framework systematically.A point of the article is the region stratigraphical background, on the base of introduced seismic boundary into the area embraced the buried hill by seismic data, biostratigraphic stratigraphical analysis and seismic unconformity analysis, and integrated application of litho-electric identification means, we identificate accurately stratigraphical boundary and establish the stratigraphic framework. This paper outlined an analysis of the stratigraphy fitted to the area embraced the buried hill which is introduced boundary based on the seismic data, controlled comprehensively by mutil-factor. The Research indicates that the Stratigraphy of Shahejie formation consisting of stratigraphic units of Es₄^x, Es₄^s (Es₄^cx&Es₄^cs), Es₃^x, Es₃^z, Es₃^s, Es₂^x, Es₂^s-E_s¹.Shicun fault exercised the most important influence on Es4-Es3x, but Es2 and others.On this basis, the Shahejie Sedimentary Facies of study area have been studied systematically. Shallow lake and half-deep lake are main facies in Es₄^s.Delatatic deposit develop prosperously in Es3.With the delta continue to advance from east to west, the lake basin is reduced and delta surfaces fully developed. After the role of delta bodies tianpingbuqi in the sedimentation period of the delta, deltfront submersed channel is mainly sedimentary facies in Es₂^x. From Es₂^s to E_s¹, lake basin is shrinking, and material source of supply is to weaken, so the beach-bar is dominated in the sedimentary facies.