Changes in prevailing surface-paleowinds reveal the atmospheric circulation transition during Early Cretaceous in North China

Eolian deposits, which record the geological history, have long been a hot topic in geoscience research for they are not only a sensitive indicator of paleoclimate, paleoecology, and paleoenvironment but also a basis for the reconstruction of the global paleocontinent and paleogeography. Upper Mesozoic eolian deposits, especially Lower Cretaceous eolian deposits, are widely developed in the North China Craton and show a transition of the paleocurrent from easterly to westerly. However, the driving mechanism and influence range of this transition remain unclear. In this study, we systematically investigated eolian deposits from the Lower Cretaceous in North China and conducted detailed sedimentological studies on the eolian deposits of the Lower Cretaceous Luohe Formation and Yijinhuoluo Formation in the Ordos Basin. Based on the data of approximately 850 dip-azimuths from large eolian cross-bedding foresets of 65 groups in 14 sections, we reconstruct the prevailing surface-paleowind directions and classify the paleowind belts of North China. The study demonstrates that the Yijinhuoluo Formation in the northeastern part of the Ordos Basin is the product of the easterly belt, whereas the eolian deposits of the Luohe Formation, which are widely developed in the basin, are a response to the westerly belt. In addition, combined with the paleo-current data from different regions of Northern China, this study exhibits that the true polar wander model cannot adequately explain the paleo-current variation; furthermore, it indicates that the transition of the Earth's surface atmospheric circulation in the same period may be the real driving mechanism. Influenced by the “great Jurassic east Asian aridification” and the Cretaceous “super greenhouse” during the Jurassic/Cretaceous transition period, the subtropical high belt was compressed from approximately 40°N in the Early Cretaceous to 30°N or even lower in the Middle Cretaceous. The migration of the subtropical high belt resulted in a change in atmospheric circulation in the study area, and the change in prevailing surface paleowinds during the same period was the sedimentary response to the atmospheric circulation transition. •Sedimentological characteristics of Luohe and Yijinhuoluo Formation are studied.•Variation law of the paleowind during the Cretaceous in Ordos Basin is found out.•The change of paleowinds during Early Cretaceous is caused by climate change.