The Lower Cretaceous ultra-thick Luohe Formation aquifer is the main water-filled aquifer forcoal mining in the Dafosi wellfield in the southern part of the Ordos Basin. In order to identify thepalaeoenvironment, palaeoclimate and its material provenances, samples of sandstones were systemati-cally collected for trace element and rare earth element geochemical analysis. The results show that theredox indicators of the sandstones of the Luohe Formation are low, with U/ Th ranging from 0. 17 to1. 07, with an average of 0. 37; Ni/ Co ranging from 1. 14 to 2. 17, with an average of 1. 67; AU rangingfrom - 1. 33 to 7. 29, with an average of 0. 28; Ceanom ranging from - 0. 21 to - 0. 07, with an averageof - 0. 17, indicating an oxic environment in the water column during the deposition of the Luohe For-mation. Co contents range from 4. 38 to 20. 06, with an average of 8. 21, quantifying the average paleo-depth of 4. 14 m during the deposition period, which is a shallow water environment. Sr/ Ba ratios aremoderate, ranging from 0. 33 to 1. 99, with an average of 0. 82; Th / U ratios are high, ranging from 0. 93to 5. 94, with an average of 3. 10, indicating a terrestrial freshwater environment during the depositionof the Luohe Formation. Sr/ Cu ratios are high, ranging from 12. 90 to 362. 84, with an average of95. 12; Rb / Sr ratios are low, ranging from 0. 13 to 0. 72, with an average of 0. 29, indicating depositionin a dry climatic context. It reflects that the Luohe Formation in the Dafosi Wellfield is a terrestrialshallow water deposit formed in an oxic environment and a dry climatic context. The rare earth elementspatterns of the sandstones from the Luohe Formation are more consistent with the North Qinling, indi-cate that its provenance is from the North Qinling Mountains, which is mainly a mixture of felsic andbasaltic provenances and andesitic island arc provenances.