Hoàng Văn Long, Vũ Trường Sơn, Trịnh Nguyên Tính, Lê Anh Thắng, Trịnh Thanh Trung, Trần Thị Oanh
The results derived from grain-size analysis, geomorphological study, heavy mineral investigation together with hydro-lithodynamics data showed that: surface sediment within the study area was subdivided into 3 zones: Coastal lagoons consist of finegrained sediments, which have been deposited in the anoxic, low energy environment; Coastal zone characterized by coarse-grained sediments under stronger wave and tide regimes; Nearshore zone mostly comprises of silt and clay mixed by sand and gravel in the deeper environment. The distribution law of the surface sediment demonstrated that the coastal area is dominated by coarse-grained sediments characterized by local sources, poor roundness and sortness. The proportion of the finer grains increases in water depth. Reddish brown gravels observed at 40-50 m of water depth are products of the in-situ weathering process during the Last Glacial Maximum occurred prior to the Flandrian Transgression. The coarse gravel sequences are potential objects for construction material while the fine-grained, well sorted sand formation demonstrates high grade of mineral placers.
Người biên tập: TS. Nguyễn Tiến Hải.