Early Cretaceous (late Barremian−Early Albian) expanding aeolian activity in East Asia: Evidence from the stratigraphic evolution of aeolian deposition in the Baiyin-Jingyuan Basin, northern China

Cretaceous aeolian deposition is important for understanding variations of the tropical−subtropical atmospheric circulation under greenhouse background. Nevertheless, detailed records revealing response to rising CO2 are still lacking. To shed light on their linkage, we examined Early stratigraphic evolution Hekou Group in Baiyin-Jingyuan Basin, northern China, using multiple methods. The results indicate that lower characterized by a transition from submerged alluvial shallow lacustrine deposition. Overlying these facies loess-like without bedding, distinguished grain-size distribution, surface microtextures, and geochemical analysis, which followed palustrine In deposition, sand-dune sand-sheet can be identified, gradually developed upward Group, with intercalated wet interdunes, damp pebble-sand sheetflood beds. Finally, sand dunes sheets dominated upper Group. Overall, upward-changing indicated development an aqueous environment, long-term paleoclimatic shift semi-humid, semi-arid extremely arid, reflects expanded activity East Asia during Cretaceous. Furthermore, various were combined investigate expanding Asia, indicates west−east-trending arid belt was wider than modern counterpart late Barremian−Early Aptian Aptian−Early Albian, respectively. These stepwise expansions mainly driven CO2, strengthened subsiding branches Hadley subtropical high, eventually leading intensified aridification.