Estimate of Unconformity Time Gaps and Denudation Using Cenozoic Astrostratigraphic Data from Northern Changwei of
详细信息
- 责任者：Li Wentao (College of Earth Resources and Information ; China University of Petroleum ; Dongying 257061 ; China)
- 刊名：Journal of Stratigraphy
- 出版年：2010
- 卷期：34(3)
- 关键词：地层学 ; stratigraphy ; 不整合 ; unconformities ; 山东 ; Shandong Province
- 页码：p.268-282
- 图表：9 illus., 6 tables, 40 refs.
- 分类号：1200
- issnNo：ISSN0253-4959
- isbnNo：CN32-1187/P
摘要
///Cenozoic unconformity time gaps and denudation in northern Changwei of Shandong Province was estimated using astrostratigraphic methods based on data from 9 formations in the Niutouzhen,Houzhen and Weibei sags in the Changwei Depression. Astrogeologic research methods applied in this paper include stratigraphic division, spectrum analysis based on logging data, and recognition and correlation of 400 000 year cycles. On the basis of denudation time and sedimentary environmental analysis,the following conclusions were arrived : 1) the sedimentation of Eogene formation in the northern Changwei depression was basin wide and stable before 48.448 Ma. During the sedimentation of Ek3 there were basalt eruptions lasting 4 Myr; Ek2 （lasting approximately 7 Ma） is featured by swamp and shallow lake sedimentation, Ek1 （lasting approximately 6 Ma） is featured by red colored sediment deposited in arid lacustrine environments; 2) from 48.448 Ma （the Shahejie Formation） to 23.03 Ma（ the Dongying Formation）, sedimentation and subsidence continued,particularly in the central Weibei sag where Changcan 1 well and Chang 1 well are located; 3) the study area uplifted from 23.3 Ma to 12 Ma（ the Guantao Formation）. During 10 million years of denudation, deposits laid down in the Es3-Dongying Formation were eroded and incorporated in the lower Es4 Formation; and 4) from 13 Ma （ the upper Guantao Formation） to 2.588 Ma （the upper Minghuazhen Formation）, mudstone and fine siltstone were laid down, forming a cap rock.