loading page

Evolution of the continental margin of south to central Vietnam and its relationship to opening of the South China Sea (East Vietnam Sea)
  • +3
  • Hiep Nguyen Huu,
  • Andrew Carter,
  • Long Van Hoang,
  • matthew fox,
  • Sang Nhu Pham,
  • Hau Vinh Bui
Hiep Nguyen Huu
Hanoi University of Mining and Geology

Corresponding Author:nguyenhuuhiep@humg.edu.vn

Author Profile
Andrew Carter
Birkbeck, University of London
Author Profile
Long Van Hoang
Vietnam Petroleum Institute
Author Profile
matthew fox
Author Profile
Sang Nhu Pham
Hanoi University of Mining and Geology
Author Profile
Hau Vinh Bui
Hanoi University of Mining and Geology
Author Profile


The continental margin south to central Vietnam is notable for its high elevation plateaus many of which are covered by late Cenozoic basalt flows. It forms the westernmost margin of a wide continental rift of the South China Sea (East Vietnam Sea), and uplift has been considered a result of either rifting or younger intraplate basalt magmatism. To investigate margin development apatite thermochronometry was applied to a dense array of samples collected from across and along the margin of south to central Vietnam. Results, including thermal history models, identified a distinct regional episode of fast cooling between c. 37 and 30 Ma after which cooling rates remained low. The fast cooling coincides with a period of fast extension across the South China Sea (East Vietnam Sea) region that preceded continental break-up recorded by Oligocene grabens onshore. A thermal model is used test different processes that might influence the inferred cooling including a distinct pulse of exhumation; a decrease in exhumation followed by an associated transient decrease in geothermal gradients and, underplating coincident with rifting. Thermal relaxation following Mesozoic arc magmatism is ruled out as geotherms returned to background rates within 20 Myrs of emplacement, well before the onset of fast cooling. Models support fast cooling attributed to accelerated erosion during early stages of rifting. Some additional heating from either underplating, and/or hot mantle upwellings is also possible. No evidence was found to support regional uplift associated with the intraplate magmatism, enhanced monsoon-driven erosion or seafloor spreading dynamics
Feb 2022Published in Tectonics volume 41 issue 2. 10.1029/2021TC006971