The syn‐depositional fault control of the evolution of axial meandering river delta‐sublacustrine fan deposits during the Ed2x deposition in the northern Liaodong Bay, Bohai Bay Basin, NE China

Abstract

This research study presents the results of an integrated study employing core samples, wireline logs, and seismic dataset collected in the study area for analysing the syn‐depositional fault's control of the evolution of the axial meandering river delta‐sublacustrine fan deposits during the Ed2x depositional period. The results indicate that the delta deposits that had developed during a retrogressive period, with the characteristics of retrogressive stacking patterns, had resulted from a high subsidence rate caused by the syn‐depositional faults with large fault throw. These appeared to be characterized by strong amplitude, low frequency, and continuous seismic reflections on the seismic profiles, and high‐amplitude serrated cylinder‐shaped stacking patterns in the wireline logs, with no obvious sedimentary structures. In contrast, the delta deposits developed during a progressive period and characterized by progressive stacking patterns were determined to have resulted from a low subsidence rate caused by the syn‐depositional faults with small fault throw. They were found to be characterized by weak‐to‐medium amplitude vermicule‐shaped seismic reflections, as well as low‐amplitude bell‐shaped or funnel‐shaped stacking patterns, with soft‐sediment deformation structures.