Abstract:

 An investigation on the midCretaceous continental sediments was recently executed in both SW Zhejiang and SW Fujian provinces, SE China. It is the first time to report the Cretaceous paleosols in mainland China. Three types of paleosol are recognized as argillisol, calcisol, and oxisol based on the observation of eleven cross sections in field. The argillisol horizon is characterized by burrows and root traces within reddish (silty) mudrock, the calcisol is marked by calcareous concretion within pale purple calcareous mudrock, and the oxisol is the association of ferric tegument and concretion within reddish purple, grayish orange siltstone and mudrock. According to climate direction of paleosol type, it is proposed that it could have been in aridity or semiaridity of subtropic during the AptianAlbian epoch of the midCretaceous in SW Zhejiang, where the calcisol was recorded in the Hengshan Formation, Zhongdai Formation, Jinhua Formation, Guantou Formation, and Chaochuan Formation; and at the same time, it was in semiaridity of tropic in SW Fujian indicated by oxisol within the Bantou Formation, Junkou Formation, and Shaxian Formation. In the Cenomanian, it could have become more moisture in SW Zhejiang evidenced by the production of the argillisol within the Quxian Formation, whereas the paleoclimate in SW Fujian in the Cenomanian might have been similar to that in the AptianAlbian even if the sediments were changed as huge conglomerates (socalled “Danxia Landorm”) by tectonism.

Key words: paleosol; paleoclimate; midCretaceous; Zhejiang; Fujian