Characteristics and distribution pattern
of the surface sediments in the inner
shelf of B́nh Định
Province
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.