Regularity of paleowind directions of the Early Cretaceous Desert in OrdosBasin and climatic significance

By the measurement of the wind directional indicator of the Cretaceous dese rt in Ordos Basin, the regularity of the paleoprevailing wind directions an d pattern of the paleowind belts are revealed. It is considered that the de sert was controlled by a planetary wind system. In the early stage, the sub tropical high pressure zone drifted south and northwards with short cycles, resulting in the alternation of westerlies and northeast trades; in the la te stage, the subtropical high pressure zone drifted southwards with a long cycle, placing the desert under the westerly belt and making the desert co mpletely controlled by the westerly belt. The reconstruction of the paleowi nd belts has provided the evidence of the general circulation of the atmosp here for the pattern of the circulation before the uplift of the Tibetan Pl ateau.