Coastal Quaternary morphologies on the northern coast of the South China Sea, China, and their implications for current tectonic models: A review and preliminary study

Kevin Pedoja (1) , Jian-Wei Shen (2) , Steve Kershaw (3) , Cheng Tang (2)

1 M2C - Morphodynamique Continentale et Côtière
2 Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology and Guangzhou Institute of Geochemistry
3 Institute for the Environment [Uxbridge]

Marine terraces, tidal notches and sediments along a 1200-km-long stretch of the northern coast of the South China Sea passive margin were studied and divided into five areas with varying tectonic characters. Up to three marine terraces occur, that have elevations reaching up to 60 m above mean sea level (amsl), and two marine notches occur up to 11 m amsl. Chronology of the morphologies and deposits was obtained mainly by comparison with Quaternary sea levels derived from the oxygen isotope curve. However, prior to the last interglacial highstand (MIS 5e, c. 125 ka), evidence of history of events is less well-constrained, leading to less precision on sea-level positions prior to MIS 5e. Using the morphological features of MIS 5e as a marker, mean coastal uplift rates in the last c.125 ka range from 0.07 mm/yr to 0.18 mm/yr. The pattern of deformations is slightly higher than those observed on passive margin coasts in other parts of the world. The cause of uplift of the south China coastline is not clear, but may relate to the Himalayan collision zone or any other large-scale phenomena.

Mots clés: marine terraces; marine notches; South China Sea; passive margin

Domaines: Interfaces continentales, environnement

Kevin Pedoja, Jian-Wei Shen, Steve Kershaw, Cheng Tang. Coastal Quaternary morphologies on the northern coast of the South China Sea, China, and their implications for current tectonic models: A review and preliminary study. Marine Geology, 2008, 255, pp.103-117. ⟨10.1016/j.margeo.2008.02.002⟩. ⟨hal-00358775⟩