Abstract:

Based on field study on some central bar in Nanchang section, Ganjiang river, following details were studied: (1) sedimentary characteristics of sediments in different parts of central bar; (2)characteristics of muddy layers and their distributions; and (3)forming process of central bar. The head has the strongest hydrodynamic and sediments are mainly coarse sand and fine gravel, with a good lateral continuity; the wings has a strong hydrodynamic and sediments are also coarse, with many boulder clay; the top and tail have horizontal continuous mud layers. Mud layers tend to harden and crack, and fragments are apt to be carried by water. Mud layers kept down distributed limited and subhorizontal. Mud layers control vertical heterogeneity with a good lateral connectivity.

Key words: Nanchang section, Ganjiang river, central bar, sedimentary characteristics, nonhomogeneity