Late Cretaceous eolian dunes and wind directions in Xinjiang basin, Jiangxi Province, China.

The Tangbian Formation (K2t), middle part of the Late Cretaceous Guifeng Group in Xinjiang Basin, Jiangxi Province, has long been thought to be aqueous. However, based on our study, it is attributed to eolian. Many evidences, including purple red, well sorted and rounded, medium to fine-grained pure sandstone with little suspension load such as clay, silt and mica, well developed thick, large scale and high dip tabular planer cross-bedding characterized by eolian dune foresets and typical eolian grain surface textures such as dish-shaped impact scars, crescent-shaped impact scars and frosted surface under electronic microscope, indicate that the Tangbian Formation was deposited in eolian dune environment. The paleo-current reconstruction has proved that the dominative prevailing is westerly and second prevailing is northeasterly with a little amount of southeasterly and northwesterly. Based on the paleogeography and earth surface wind belt model, the studied area was located in the Cretaceous between north hemisphere westerlies and northeast trades and possibly influenced by southeast and northwest monsoons.