Discovery of a 1.0 Ma Yellow River Terrace and redating of the fourth Yellow River terrace in Lanzhou area

Abstract

Abstract Based on the Aeolian loess sequence-stratigraphic division and paleomagnetic dating on terraces, we found that an undiscovered terrace with the age of 1.0 Ma BP lies between the Dunwashan terrace and Wuyishan terrace. This recorded an intensive yellow River incision event during that period. Results of paeomagnetic dating and optically stimulated luminescence (OSL) dating of the Wuyishan loess section and Zaoshugou loess section on the fourth Yellow River terrace (T4) show that the age of the fourth Yellow river terrace in Lanzhou area is 0.86 Ma terrace in Lanzhou area. The discovery of the 1.0 Ma Yellow River terrace and redating of the age of 0.6 Ma terrace in Lanzhou area provide new insights into further research on the evolution of Yellow River. *Supported by National Natural Science Foundation of China (Grant Nos.40421101 and 40471016), and the Major State Basic Research Development Program of China (Grant Nos. 2005CB422001)