SUMMARY

Tectonic zones of continental southern Việt Nam

Nguyễn Xuân Bao, Dương Văn Cầu, Trịnh Văn Long

The mailand part of Southern Vietnam beginning from West Thừa Thiên - Huế to the South includes the following main tectonic zones: The Kon Tum high grade polymetamorphic terrane is distributed in Mid of Trung Bộ. The core of this zone includes Paleoproterozoic-Mesoproterozoic Ngọc Linh - Kan Nắck block and the edge is composed of Hiệp Đức - Sa Thầy Early Caledonian orogenic belt and Ea Kar-Ea Drang Late Caledonian orogenic belt. In the Kon Tum high metamorphic terrane there develop strongly after Caledonian diverse and multistage petrotectonic assemblages; The Sre Pok-West Nam Bộ Indosinian orogenic belt distributed mainly in West South Trung Bộ and West Nam Bộ. This is Southern Vietnam part of Mekong Indosinian orogenic belt and actually is the Western edge of Indochina continent. This tectonic unit had underwent the Late Carboniferous-Permian extensional continental margin and Triassic collisional orogeny against Simubasu continent settings; The Đà Lạt Early Yanshan orogenic belt disposed in South Trung Bộ and East Nam Bộ. The orogenic activities occurred in Late Jurassic-Early Cretaceous time when the Southern Vietnam continental margin collided against Spratly- Luconia microcontinent.

    Besides in South Việt Nam there are the following important overprint tectonic units: 1) South Vietnam Late Mesozoic extensional magmatic Arc, 2) Central Highland Late Cenozoic diffusion basalt Province and 3) Mekong Delta Late Cenozoic extensional Basin.