Early Cretaceous desert and the reconstruction of palaeowind belts in Gaolan-Baiyin-Jingyuan area, Gansu Province

Based on previous researches on Early Cretaceous desert of Hekou Group (K1H) in Baiyin-Jingyuan area, the authors made a synthetic comparative analysis of sedimentary texture and structure as well as typical eolian grain surface texture of Hekou Group in Gaolan area, and reached the conclusion that there must also exist desert sediments in Gaolan area. Then, the palaeowind direction and palaeowind belt were reconstructed by systematical measurement of the dips of the eolian dune foresets in the study area. The results indicate that west winds were prevailing during late Early Cretaceous in the study area, being consistent with the palaeowind direction recorded in the Luohandong Formation (K1l) in Ordos basin. The consistency of the lithologic character and palaeowind direction recorded in K1H and K1l indicates that the study area and Ordos basin were then located within the same westerlies in the northern hemisphere and the study area might have been part of the Ordos palaeodesert sea.