Palaeochannels on the North China plain: Palaeoriver geomorphology

Abstract

Variations in the geomorphology of the North China Plain are related to differences between river deposits. The river deposits from different periods form the various geomorphological features; different combinations of palaeochannels form different geomorphological regions; different kinds of palaeochannels form different kinds of micro-geomorphology. During the early glaciation of the late Pleistocene, the river deposits formed piedmont plains and floodplains. By the early Holocene, the rivers had cut the piedmonts into dissected valleys and deposited alluvial fans at the front edge of the piedmonts to form alluvial plains below. By the middle Holocene, lake sediments covered the alluvial plains and filled in the dissected valleys of the piedmont plains. By the late Holocene, rivers dissected the piedmonts again to form dissected valleys and deposited alluvial fans in the lower reaches to form alluvial plains and deltas at the river mouths.