Abstract: Field investigation was carried out along the Shaanxi-Shanxi Uorges in the middle reaches of the Yellow River.Typical palaeoflood slackwater deposits of the Holocene age were found at the Pingduguan sites.They were identified by sedimentary criteria during fieldwork initially

sampled and invested in detail.Analysis of the grain-size distribution

loss orrignition and CaCO3 content indicated that these slackwater deposits consisted of sandy silt

silt fine sand and sand.They were classified as sandy silt

silt fine sand and sand in contrast to loess and paleosoil which were classified as clayey silt on the loess tableland in the middle reaches of the Yellow River.The magnetic susceptibility of the slackwater deposits was very low because they were newly deposited and unaffected by weathering and pedogenesis.The CaCO3 content of the slackwater deposits was between paleosoil and loess indicated that the suspended sediment load is mixture of aeolian loess and sand

which came from the windy and sandy areas.They were well sorted because of long distance transportation in floodwater.The shape of particle-size distribution curves of the slackwater deposits was high and thin.It represented a low turbulence deposit.