Characteristics and ages of the Pleistocene lithostratigraphy and biostratigraphy in the Huailai-Zhuolu basin, Hebei

The Pleistocene of the Huailai-Zhuolu basin in Hebei could be subdivided in ascending order into the Nihewan, Guanting, Malan and Jijiaying Formations, of which the Jijiaying Formation is a newly established lithostratigraphic unit. Detailed biostratigraphic study reveals that the sequence could contain 3 Ostracoda assemblages, 3 Lamellibranchiata and Gastropoda assemblages and 8 sporopollen assemblages, whose ages are discussed on the basis of radioactive dating.