Study on the base-level cycle and the sedimentology of Permian in Jiyang area

• 来源期刊: 煤炭学报（英文版）
• 年，卷（期）: 2009,（1）
• 页码范围: 7-15
• 页数: 9页
• 语种: 英文
• DOI: 10.1007s12404-009-0102-0

摘要

The identification of sequence boundaries is the key point for sequence strati-graphic classification.Both the higher-order sequences and the units within the sequences are bounded with the key sediments or isochronous surfaces.Eight sequences can be di-vided in the whole Permo-Carboniferous strata (the Shiqianfeng Formation is not included),which is from the Benxi Formation,Taiyuan Formation,Shanxi Formation,Xiashihezi For-mation,Wanshan Section,and Kuishan Section to the Xiaofuhe Section.Also,different system tracts (Iowstand system tract,transgression system tract and highstand system tract) and some parasequences can be recognized in each sequence.Parasequence analysis was on the basis of the division of the base-level cycle.The base-level cycle was mainly identified according to the change of the water area,which was reflected by the depositional sequence.The physical characteristic of the strata was reflected by the well log.It was supplied by the test of the minerals and rocks and the analysis of the micro-element in the lab.The paleogeographic characteristic of the Iowstand system tract in the sequence VI is that the east-north part takes the river system as its feature; the south part is the lake system,the river channel spreads from north to south,and the area of the flooding plain is great.The paleogeographic characteristic of the water-transgressive sys-tem tract is that the range of the lake in the south extended distinctively,the range of the river channel in the east reduced.The coastal shallow lake deposit is the main character-istic in the water-transgressive system tract.The paleogeographic characteristic of the highstand system tract is similar to the one of the Iowstand system tract.