GRAIN SIZE CHARACTERISTICS OF THE CORE SEDIMENTS IN THE EASTERN LIAODONG BAY AND IMPLICATIONS FOR DEPOSITIONAL ENVIRONMENT

Four cores of sediment taken from the Eastern Liaodong Bay were analyzed for grain sizes. The results indicate that the saltation component of the Core LDC47 sediments on the north of the tidal sand ridge is as high as 70%, which is composed of two straight lines in the probability cumulative frequency diagram. It means that the sediments of Core LDC47 were formed under a to-and-fro current and indicates an origin of tidal sand ridge. It is deduced that these sediments are mainly from the Laotieshan Channel. However, the saltation component of the upper part (0~2.10 m) of the Core LDC30 is less than 40%, showing as a straight line in the probability cumulative frequency diagram, as the lower part shows no difference with the upper. The saltation component in the lower part is even much lower. It suggests that the upper part of Core LDC30 was probably formed in a pro-delta environment of the highstand system tract, whereas the lower part of the Core LDC30 was deposited in a wetland or tidal flat environment. The upper part of the Core LDC71 and LDC82 are thin with high suspension component and become coarser downwards. The sediments of the Core LDC30, LDC71 and LDC82 are all belonging to coastal sands possibly derived from the rivers nearby and coastal bed rock erosion.