Characteristics of modern sedimentation in Qingdao bays

Abstract

With available survey data and 237 surface sediment samples, the modern sedimentation in Qingdao bays is studied. The research result shows that the east area is shallower (16.4 m) than that in the west (45.8 m). The geography was formed by a symmetric wave in a sequence of bank — offshore depression — platform — tidal channel — platform — offshore depression — foreshore from south to north. Flood sedimentary systems were formed from inlet of the Jiaozhou Bay in the west to the barrier bar in the east. Lateral sedimentation includes mainly tidal current ridges in two tidal channels. Gravel sandy sediments formed by wave lie in midland of from seashore to wave base. Dynamic functions are mainly tide and wave. Tidal current moves sediment in vertical and horizontal directions, sorting sediments and providing materials for coastwise beaches. The sources of sediment are mainly from eroded headland rocks. In general, grain sizes in this area from the inlet of the Jiaozhou Bay in the west (120°17′) to the barrier bar outside in the east (120°35′) are coarse-fine-coarse, forming gravel-gravelly sand (G-S), sand (S), gravel clay silt (G-YT), clay silt (YT), gravelly silty sand (G-TS), silty sand (TS), gravelly sandy silt (G-ST), and sandy silt (ST) in turn.