宁夏同心县清水河全新世地层

详细信息

THE PINGXIANG THRUST NAPPE STRUCTURE IN GUANGXI

摘要: 宁夏清水河谷盆地广泛发育全新世冲积层，构成二—三级阶地，主要为一套粉砂质土、亚砂土夹砂砾石层。内含丰富的孢粉计９０余属种，自下而上建立３套孢粉组合。经区域对比，其年代地层分别相当于下、中、上全新统。古气候经历了寒冷干燥—温暖偏干—干旱的演变。
- 宁夏 /
- 清水河 /
- 全新世地层 /
- 孢粉组合
Abstract: By means of a study of macroscopic and microscopic structures and applications of such methods as the balanced section and finite strain measurements, it has been demonstrated that the Pingxiang thrust nappe structure is a large scale imbricate thrust nappe structure formed in the platform cover under the NW-SE compression. It, ＞30 km long, generally strikes 25-40° and dips SE at 20-30° and is thrust at 307°. Calculation of the balanced section gives the shortening rate e= -33.3%, the relative length ratio ε r=66.7%, the thrusting distance ＞5625 m and the NW-SE direction of the maximum principal stress σ 1. The structure was formed in the Indosinian Yanshanian.
- thrust nappe structure /
- balanced section /
- strain analysis /
- Pingxiang