SUMMARY

Upper Pleistocene - Holocene sediments on the continental shelf
of Vũng Tàu - Bình Thuận area (Mekong paleo-terrace)

Nguyễn Tiến Hải, Nguyễn Huy Phúc

On the basis of data interpretation from high resolution shallow seismic profiles, sediment corer and the shoreline located at the depth of Holocene transgression: -98 m (about 14.700 years BP), -60 m (~10.700 years BP), -28 m (~9.200 years BP) and +5 m (~5.000 years BP), the Late Pleistocene - Holocene formations on the Mekong paleo-terrace could be divided into four members:

- Member 1. Upper Pleistocene, part b - Lower Holocene, part a (Q₁^3b-Q₂^1a): fluvial deposits (sand with minor grit?), marshy deposits (dark-grey mud and clay), fluvio-marine deposits (sandy mud bearing plant remains), littoral deposits (muddy sand with some shell fragments); thickness: 0-10 m.

- Member 2. Lower Holocene, part b (Q₂^1b): fluvio-marine deposits (grey, yellow-grey sand and silt), littoral deposits (slightly gravelly sand mixed with shell fragments), sand ridges (fine- to medium-grained, well sorted and rounded sand); thickness: 0-5 m.

- Member 3. Lower Holocene, part c - Middle Holocene, part a (Q₂^1c-Q₂^2a): fluvio-marine deposits (light-grey, yellow-grey muddy sand), gulf deposits (dark-grey sandy mud), sand ridges (light-grey, medium-grained, well sorted and rounded sand), marine deposits (green-grey mud); thickness: 0-8 m.

- Member 4. Middle Holocene, part b - Upper Holocene (Q₂^2b-Q₂³): estuarine deposits (light-grey sand), fluvio-marshy-marine deposits (dark-grey sandy mud), littoral deposits (dark-grey mud and clay), fluvio-marine deposits (muddy sand bearing plant remains), littoral deposits (slightly gravelly muddy sand mixed with some shell fragments), coral reef, sand dunes (rose, yellow and light-grey, fine- to medium-grained, well sorted and rounded sand); thickness: 0-10 m.

Ngày nhận bài: 24/4/2007

Người biên tập: Ngô Quang Toàn