Climatically driven formation of the Tangxian planation surface in North China: An example from northwestern Zhongtiao Shan of the Shanxi Graben System

Abstract

The development of planation surfaces requires stable tectonic and climatic conditions. However, it is difficult to discuss in detail how tectonic movement and/or climate change affects erosion, deposition, and uplift associated with the development, formation, and disintegration of planation surface. This article presents a case study on the development and formation of the Tangxian planation surface (TXPS) by establishing the magnetostratigraphy of one piedmont deposition section related to planation, and combining the depositional sequence overlying TXPS and basin sediments. Further, we discuss the role of tectonics and climate change in the geomorphic evolution of the TXPS during the late Cenozoic and revise the final formation age to be ca. 3.1 Ma by the relative deposition process. The vertical rates of the main fault constrained by different geomorphic surfaces and stable deposition in the basin show stable and moderate tectonic activity in the study area since the Pliocene, and a series of sedimentary records reveal that the climate in North China was stably warm-humid from the late Miocene to early Pliocene. Stable tectonic activity and stable climate were important bases for pediment development; however, abrupt climatic changes during the late Pliocene might be the main driving force of the final formation of the TXPS in North China.