SUMMARY

Sequence stratigraphy of the Mid- Miocene sediments in the Center of Nam Cn Sơn Basin

Nguyễn Văn Kiểu, Bi Việt Dũng, Nguyễn Thanh Tng, Phạm Thị Diệu Huyền,
Phạm Hồng Trang, Phạm Nguyễn H Vũ, Phng Xun Qun

Based on the integration and analysis of seismic, petrophysical and biostratigraphic data, we divided the Mid-Miocene sediments in the Center of Nam Cn Sơn Basin into 4 sequences using sequence stratigraphic methods: S1, S2, S3 and S4. The sequence boundaries are uncomformable and comformable surfaces which are connected on the basis of seismic and well data, including: MRS-1 (15.5 Ma), MRS-2 (14.0 Ma), MRS-3 (13.1 Ma), MRS-4 (12.1 Ma) and MRS-5 (10.4 Ma). In each sequence, trangressive system tracts (TST) and regressive system tracts (RST) are determined by the maximum flooding surface (Mfs). The trangressive system tracts (TST) of S1 sequence and S4 sequence is less widely distributed than that of the S2 and S3 sequences, and is mainly concentrated to the East-Southeast of the study area. The latest Mid-Miocene sediments correspond to the regressive system tracts (RST) of S4 sequence are marked by significant erosion activities of the ancient river bed developed along the Northwest - Southeast and West-East direction.

Keywords: Sequence stratigraphy, Middle Miocene sediments, Nam Cn Sơn Basin.