SUMMARY
Zoning characteristics of lithosphere of the
Việt Nam territory and adjacent areas
on the basis of geophysical data
The zoning characteristics of lithosphere of the Việt Nam territory has
been examined on the basis of the following methods: 1/ Seismic tomography for
determination of P wave velocity of lithosphere and mantle; 2/ Structural zoning
on the basis of geophysical data (gravity, geomagnetic and tomography). The
study results have shown that:
1. The average P wave velocity in the main layers of the lithosphere of
Việt Nam territory and adjacent areas are as follows: for basement, P = 2.10 –
4.96 km/s2; for crystallized crust, P = 5.92 – 7.60 km/s2;
for upper mantle, P = 7.85 – 8.00 km/s2; for asthenosphere, P = 8.00
– 8.20 km/s2; for transition zone (from the depth of 450-470 km to
650 km), P = 9.50 - 10.50 km/s2; and the lower mantle has the P of
10.80 - 10.95 km/s2.
2. There are three forms of the Earth crust in Việt
- The following structural units belong to the continental crust: East
Bắc Bộ, West Bắc Bộ, Trường Sơn, Kon Tum, Đà Lạt, Cần Thơ, Hà Tiên and Hải
- The following structural units belong to the transitional crust: Sông
Hồng, Bạch Long Vĩ, Lôi Châu, Châu Giang, North Hoàng Sa,
Tri Tôn, Phú Khánh, Hoàng Sa, Trường Sa, Suối Ngà - Trăng Khuyết,
- The centre of
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Người biên tập: Phạm Năng Vũ