Abstract:Analyzed the geochemical analysis data of major elements, trace elements, and rare earth elements (REE) of the Lower Cretaceous sandstone, we studied its sedimentary cycle characteristics, chemical weathering, structural background, and material sources of the sandstone.Methods:Based on the geochemical analysis of major elements, trace elements and rare earth elements (REE)of the Lower Cretaceous sandstone in Zhenyuan area of Ordos Basin, this paper discusses the sedimentary recycling characteristics, chemical weathering, tectonic background and material source of the Lower Cretaceous red variegated sandstone. Results: ① The Lower Cretaceous Luohe Formation, Huanhe Formation and Luohandong Formation are similar in provenance main body, and have good inheritance in structural background, provenance area and provenance characteristics. The REE distribution pattern curves of rare earth elements are consistent, with clear fractionation of light and heavy rare earth elements, enriched in large ion lithophile elements Ba, Pb, Sr, and light rare earth elements, and depleted in high field strength elements Nb, Ta, Th, Y, etc. From bottom to top, with the formation becoming newer, the total REE content in Sedimentary rock tends to decrease, and the fractionation degree of heavy REE decreases. ② The original material of the Lower Cretaceous sandstone in the study area is mainly composed of felsic and mafic mixed rocks (such as intermediate—acid intrusive rocks, felsic metamorphic rocks) and some sedimentary rocks. ③ In the tectonic setting, the passive continental margin tectonic environment is the main advantage. The debris mainly comes from the continental source area, followed by the recycled orogenic belt and the mixed source area.Conclusions: The provenance area is generally characterized by rich quartz, rich Calcite cement, more potassium feldspar or potassium rich minerals than plagioclase. The Luohandong Formation is more siliceous than Huanhe Formation and Luohe Formation, with less Calcite cement and purer quality. Most of the sediments in the study area are transported by the weathering and denudation products of the parent rock in the thrust nappe zone on the southestern margin of the Ordos Basin, Which are the first sedimentary materials. A few sediments (i.e. Aeolian sand) are formed by in- situ re- transport and accumulation, which are recycled sedimentary materials.