Abstract

Mê Kông subaqueous Delta is the wetland of the Mê Kông Delta distributed from 0 to 28 meter depth and from North of Tiểu river mouth to the South of Trần Đề river mouth. There are five sedimentary fields here, including: gravelly sand, sand, muddy sand, sandy mud and mud. Within the water depth of 0-25 m, sedimentary distribution obeys the rules of sediment differentiation of grains size, the size of grains is gradually finer with depth. Sandy sediments occur in water depths of 0-10 m, then mud sand at 10-15 m, finally mud distributed at 15 m of water depths. At over 25 meters water depth, there are sedimentary fields including gravelly sand, fine selective sand; sedimentary distribution obeys the rules of sediment differentiation of grains size, the size of grains is gradually finer from near shore to offshore. These are grey, brownish grey deposits with differentiation distribution from modern coastal line to 25 meters water depth formed in regressive period after the Flandrian transgressive period and having the age of Late Holocene (Q2³). At over 25 meters water depth, sediment fields of greenish grey gravelly sand, fine selective sand were formed in Flandrian transgressive period and having the age of Late Pleistocene Holocene (Q136 - Q2²).