Palaeochannels on the North China Plain: Stage division and palaeoenvironments

The late Pleistocene and Holocene palaeochannels in the North China Plain were divided into six stages on the basis of seven indicators: basal erosion surface and channel lag deposits, macropalaeontology, organic matter content, ground water quality, heavy minerals, grain size, and sedimentary structures. They were called the stages I-VI palaeochannels from oldest to youngest. On the basis of the percentage area and thickness of fluvial sand bodies of the total area and thickness of sediments of the same period, there were three palaeochannel development stages, or periods of fluvial activity, and two palaeoswamp development stages, or periods of fluvial inactivity, on the North China Plain during the late Pleistocene and the Holocene.