关键词: 斜向侵蚀面, 斜向沉积体, 沉积模式

Abstract: The present meandering streams in Hebei Plain, with I.28-I.79 sinuosity, are mixing loaded rivers.Usually, there is an erosional surface and a fluvial stagnant phase sediment of pebbles and muddy nodules at the base of the point-bar. Above it, sediment developed fining upward trend of the grainsize, and became silt with plant roots at the top. The depositional structures were mainly made up of trough-cross beddings, accompanied with parallel、horizontal、climbing and ripple beddings, occasionally tabular beddings, Sametimes, different deformational structures were also found.The basic units of point-bars in meandering streams are inclined bodies, One point-bar is probably composed of several diagonal sedimentary bodies. Every body had the fundamental characters of the point-bar. Every two adjacent bodies bordered each other with an inclined erosion surface. It is often situated in the upper-middle part, sometimes reached to the base of the sediment, A mark of mud or muddy silt cover on the sedimentary body is usually found, which shows significant change of the streamflow.

Key words: Inclined erosion surface, Inclined Sedimentary bodies, Depositional model