New findings regarding the Fen-Wei Graben on the southeastern margin of the Ordos Block: Evidence from the Cenozoic sedimentary record from the borehole

摘要

In the Cenozoic, fault-related basins, including the Wei River, Lingbao and Linfen basins, developed on the southeast margin of the Ordos Block. Based on the latest drilling data and previous research results, this article analysed the evolutionary processes, temporal and spatial relationships and tectonic background of these basins, and obtained the following results: (a) The Wei River Basin and the Lingbao Basin belong to a unified basin, which formed in the Palaeocene and developed gradually from east to west. (b) The Linfen Basin formed in the late Miocene and developed gradually from southwest to northeast. (c) The evolution of the basin systems was dominated by the westward subduction of the Pacific Plate in the Palaeogene and then by a combination effects of the subduction of the Pacific Plate and the uplift of the Tibetan Plateau. (d) The so-called Fen-Wei Graben is not supported by the different geological evolutionary histories of the Wei River Basin and the Linfen Basin.