Abstract:

This study applied the principle and methods of compaction restoration for reconstructing paleo-geomorphology of the Second Member of Shahejie Formation in Zhuangxi area of Jiyang Depression. The analyzing processes include four steps: (1) correcting of apparent thickness; (2) establishing of compaction equations;(3) restoring compaction of formations in each single drilling well; (4) composing maps of thickness of original layer and paleogeomorphology. As a result, the minimum value of correction coefficient for the real thickness was calculated as 0.83, based on structural map of the top of the Second Member of Shahejie Formation. The compaction rates are generally higher than 30%. Furthermore, the paleo-geomorphological maps of the Second Member of Shahejie Formation during uplift and subsidence sedimentary periods in Zhuangxi area were compiled. One highland in the middle and two sags in the eastern and the western sides of the Zhuangxi area were recognized from the maps. Beach bars occurred mainly along the two sides of Gubei paleo-uplift, suggesting the formation and development of beaches were clearly controlled by paleo-morphological uplift.

Key words: reconstruction of paleo-geomorphology, compaction restoration, beach bar, apparent thickness correcting, the Second Member of Shahejie Formation, Jiyang Depression