摘要
本文讨论了河西走廊东部地区早二叠世地层研究的有关问题,认为甘肃山丹青羊泉下二叠统剖面是北祁连山—河西走廊地区的重要代表剖面之一。以该剖面研究为依据,提出走廊东部地区下二叠统的进一步划分方案,分析该区早二叠世地层岩性特征差异的原因,并与走廊西部地区同期地层进行对比,进一步明确了大黄沟组的含意。
Based on the description of the Qinyanquan section, this paper deals with some relevant problems of the Lower Permian in the eastern part of the Hexi Corridor region. The main conclusions are as follows:
1. The Qinyangquan section, which can provide petrologic and paleonotologic information fo the division, correlation and ages of the Lower Permian in this area, may be regarded as one of the important type-sections in the Northern Qilianshan-Hexi Corridor region.
2. According to the characteristics of the petrostratigraphy and the plant fossil assemblages, the Lower Permian of this area may be subdivided into the Shanxi Formation and the Dahuanggou Formation. The former can be compared with the Shanxi formation of the North China, its geological age being attributed to the Early Permian; the later can be approximately contrasted with the Lower Shihhose Formation of the North China, its age being attributed to the late Early Permian.
3. The reasons for the variety in the lithogical characters of the Lower Permian in this area are not lithofacies, but lacuna.
关键词
河西走廊
早二叠世
大黄沟组
地层
Hexi Corridor, Early Permian, Dahunggou Formation, Lacuna, Cathaysia flora
