Tectonics and Mechanisms of Uplift in the Central Uplift Belt of the Huimin Depression

• Published in: Journal of earth science (Wuhan, China) Vol. 22; no. 3; pp. 299 - 315
• Main Author: 倪金龙 郭颖 王智敏 刘俊来 林玉祥 李月
• Format: Journal Article
• Language: English
• Published: China University of Geosciences China University of Geosciences 01.06.2011; Springer Nature B.V
• Subjects: Biogeosciences; Correlation analysis; Earth and Environmental Science; Earth science; Earth Sciences; Fault lines; Geochemistry; Geologic depressions; Geology; Geotechnical Engineering & Applied Earth Sciences; Paleogene; Plate tectonics; Porosity; Tectonics; 中东部地区; 中央隆起带; 中西部地区; 伸展运动; 地层剥蚀厚度; 惠民凹陷; 机制; 隆起构造; China; tectonic features; central uplift belt; uplift mechanisms; Paleogene; Huimin depression; Bohai Bay basin
• ISSN: 1674-487X; 1867-111X
• DOI: 10.1007/s12583-011-0183-8

The Huimin（惠民） depression is a third-level tectonic element of the Bohai（渤海） Bay basin in eastern China.The central uplift belt is the most important oil and gas accumulation zone in the depression,but the lack of adequate geological studies in the area has greatly hindered exploration and development.In this article,using seismic data,fracture mechanics,and a combination of data on fault growth indices and fault throws,we present an analysis of tectonic activity in the central uplift belt and adjacent regions.The amount of extension is calculated along balanced N-S cross-sections,along with the thickness of strata eroded from the fourth,third,and second members of the Shahejie（沙河街） Formation（Es4-Es2） in the uplift belt,by analyzing porosity and stratigraphic correlations.In addition,uplift features are described,and their timing and processes of formation are analyzed and dis-cussed.The results indicate that strike-slip and extensional tectonic movements coexisted,with the effects of the latter most obvious.The spatial and temporal nature of the extensional move-ments is varied：fault activity during the period Ek-Es4 was the strongest on the northern Ningnan（宁南） fault,and activity in the western part of the area was stronger than that in the east,which in turn was stronger than that in the central region;during Es3-Es2,the strongest fault movements were along the eastern part of the middle Linyi（临邑） fault,and activity in the western part of the area was rela-tively weak,whereas in the mid-west it was the strongest.The extensional movements were a response to the activity of the faults.The sediments in the lower part of the fourth member of the Shahejie For-mation（Es4x） show that Es4 was the time when the central belt first began to be uplifted strongly.Uplift was uneven during the Paleogene：the western part of the area was uplifted continuously,while the mid-eastern area underwent alternating periods of uplift and subsidence.During the Paleogene,a number of different tectonic features developed in the central uplift belt at different times and are manifested as follows：during the period Ek-Es4,a gentle slope was formed as part of the Zizhen（滋镇） sag;during Es3-Es2,the northern part of the central uplift belt continued to display a gentle slope as part of the Zizhen sag,but the southern region developed an steep slope as part of the Linnan（临南） sag.There are close interrelationships between uplift,strike-slip,and extension within the central uplift belt of the Huimin depression,as is manifest by the areas of strongest extension being uplifted most rapidly,and also eroded the most.