Weihe River-Mihe River Delta in South Coast of Bohai Sea,China: Sedimentary Sequence and Architecture

Weihe River-Mihe River Delta on the south coast of the Bohai Sea is contributed by the Jiaolai River,Weihe River,the Bailang River,the Mihe River and the Xiaoqing River,and the historical Jishui River existed in 11-1128 A.D.It is a river group delta.The coast line prograteded 20-55 km from 7000 yr B.P.to 1984.The delta thickness along the coast is over 20 m.The distances between two river mouths is approximately 20 km or less.The clayey silt of the prodelta is jointly constructed by all rivers,very fine sand of the delta fronts are made at the individual river mouths.and the inter-mouth bay clayey silt accumulate between two river mouths.The delta has not distinct abandoned delta lobe.The very fine sand and intermouth bay silt alternately occur in sequence in the delta front because of river mouth movement.