关键词: 黄河三角洲, 叶瓣, 划分, 识别

Abstract: Eight delta lobes have been constructed in the Modern Yellow River Delta since 1855,as a result of frequent shifting of the distributary channdls. The average acting time of the lobe is 16 years,The delta deposits formed in 1904-1929 are consisted in one of the delta lobe,The delta deposits formed in 1934-1938 and 1947-1964 make up another delta lobe,Delta deposits in the drill core are commonly composed of those from several lobes.The boundary between two lobes is mot obvious,being short of relatively coarse deposits,However,diffrent lobes still can be recorgnized based on sedimentary texture and structure,microfossils,²¹⁰Pb dating and historical documents.Coarse silt is deposited in the middle part of the river mouth and clayey silt is accumulated in the lateral parts at the depth of 0-12m in water.The migration of the river mouth results in abrupt change in lithology,which often shows the boundary of two delta lobes.The clayey silt is in abundance of foraminifera in protelphidium tuberculatum assem-blages,although the deposits are not coarse silts or fine sands.

Key words: Yellow River Delta, Lobe, Division, Recorgnition