The results of correlation of Cenozoic volcanites in the mainland and continental shelf of ViÖt Nam allow the authors to draw following statements.

1. The forming time of Cenozoic volcanites in ViÖt Nam began from Oligocene until present time.

2. Basaltic rocks have quite monotonous petrological composition, with little differentiation and they consist mainly of alkaline basalts.

3. On the petrochemical side Cenozoic basaltic rocks in the shelf and mainland of ViÖt Nam have rather similar characteristics on major oxide composition, with medium content of SiO₂ , hight content of MgO and Na₂ O , low content of Al₂ O₃ . The content of major oxides do not change very much.

As mentioned obove, it is clear that Cenozoic volcanic rocks in ViÖt Nam are intra- continental basalts related to the degradation of the continental crust in Cenozoic.