Sedimentary characteristics and paleoclimatic significance of the lower cretaceous red sandstone in the Central Ordos Basin

• Published in: Environmental earth sciences 2024, Vol.83 (2), p.46, Article 46
• Main Authors: Wang, Xiaoning, Yue, Dapeng, Zhao, Jingbo, Yang, Yuzhe
• Format: Article
• Language: English
• Subjects: Annual precipitation; Biogeosciences; Chemical properties; Chemical weathering; Chemicophysical properties; Clay minerals; Climatic conditions; Cretaceous; Deposition; Earth and Environmental Science; Earth Sciences; Environmental Science and Engineering; Geochemistry; Geology; Grain size; Humid climates; Hydrology/Water Resources; Original Article; Oxidation; Palaeotemperature; Sandstone; Sediment; Sedimentary rocks; Sedimentology; Subtropical climates; Terrestrial Pollution; Transportation; Weathering
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-023-11351-x

To explore the genesis and paleoenvironmental characteristics of the Cretaceous red beds in northwest China, 85 samples were collected from three sedimentary profiles (J1–J3) in Longzhou Town, Jingbian County. Sedimentology methods were used to analyze the physical and chemical properties of the sedimentary beds. The transport mode, transport dynamics, genesis, and quantitative climatic characteristics of red sandstones in the study area were discussed. The main conclusions are as follows: (1) Sandstone is not aeolian sediment, and its transportation is dominated by hydrodynamic forces. The overall transportation force is strong, but the dynamic strength changes erratically. (2) Sandstone was a proximal sediment, and its “red” color is caused by oxidation on land before deposition, not by underwater oxidation. (3) Sandstone was deposited under relatively warm and humid climatic conditions and subjected to strong chemical weathering. During the period of sandstone deposition, the average annual precipitation was 526.44mm to 695.34mm, and the quantitatively recovered paleotemperature was 15.20 °C, which has the characteristics of a subtropical and semi-humid climate. (4) The absence of fine particles in the thin sandstone profiles can lead to a lower weathering index value, and factors such as grain size and clay mineral content should be considered when determining the weathering degree of red sandstone.