SUMMARY

Cycles and formation of Quaternary deposits in Việt Nam

Doãn Đình Lâm

The author introduces cycles of the Quaternary established in the world and makes the correlation, comparision with 5 established cycles of Quaternary deposits in Việt Nam (Q₁¹, Q₁^2-3a, Q₁^3b, Q₂^1-2 and Q₂³). This correlation points out that the coarse-grained deposits (gravels, pebbles, coarse sands) of the Q₁¹, Q₁^2-3a and the Q₁^3b deposits may correspond to the gravel beds C, B and A of C2, T3 and C3 cycles. So, the lower boundary of the Q₁¹ deposits may correspond only to 1 Ma BP. As a result, the question on the boundary between Neogene and Quaternary in Việt Nam arose for further study. Does this boundary lay on the bottom of the Q₁¹ deposits or may be still expanded into Neogene deposits? It is an opened question to be solved; this problem requires isotopic dating of the Q₁¹ and Neogene deposits.

Ngày nhận bài: 10/01/2007

Người biên tập: Ngô Quang Toàn