HISTORICAL CHANGES IN THE YELLOW-RIVER DELTA, CHINA

The lower Yellow River delta has experienced numerous avulsions during the last 2000 years and the floodplain can be divided into four provi nces: alluvial fan, western plain, middle plain and eastern plain (coa stal deltas). The Yellow River delta complex is composed of several de lta superlobes resulting from shifts in the lower river channel, and e ach delta superlobe consists of several smaller lobes formed by shifts in the distributary channels. These two kinds of channel shifts have resulted in a complicated imbrication pattern in the delta complex. Tw o imbricated delta superlobes are divided by a reworked bed and buried shelf deposits. Shelly ridges form the surface boundaries between the various delta superlobes. The delta superlobes passed through an acti ve stage, a reworking stage and were then finally overlain by later su perlobes.