EGU2020-8920
https://doi.org/10.5194/egusphere-egu2020-8920
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

The stratigraphic and magmatic tape recorder of crustal thinning and lithospheric breakup: insights from the NW South China Sea

Peng Chao1, Gianreto Manatschal1, Nick Kusznir2, Pauline Chenin1, Jianye Ren3, and Xiong Pang4
Peng Chao et al.
  • 1CNRS UMR7516, Institut de Physique du Globe de Strasbourg, STRASBOURG, France (c.peng@unistra.fr)
  • 2Earth and Ocean Sciences, University of Liverpool, Liverpool, UK
  • 3College of Marine Science and Technology, China University of Geosciences, Wuhan, China
  • 4China National Offshore Oil Corporation Ltd, Shenzhen, China

In the last two decades, knowledge of the South China Sea (SCS) rifted margins has significantly evolved. However, there are still many open questions related to when, how, and under what conditions major crustal thinning (necking) and lithospheric breakup occurred and how these processes are recorded in the stratigraphic and magmatic tape recorder. In this study, we aim to explore the tectono-sedimentary-magmatic evolution of rift systems during crustal thinning and lithospheric breakup. Our study is based on observation of conjugate margins architecture along high resolution long offset reflection seismic sections through the Northwest SCS. We focus on crustal thinning and lithospheric breakup, and the transition to first oceanic crust and the birth of an oceanic spreading centre. We describe the Northwest SCS crustal architecture, define extensional domains (proximal, necking, hyper-extended, OCT, oceanic domain) and margin architecture (upper and lower plate). We determine the tectono-sedimentary evolution and discuss the evolution of deformation modes through time and space by linking the tectono-stratigraphic-magma evolution with the observed crustal thinning. These results have important implications for understanding the deformation history and processes in time and space, and enable the analysis and linkage of the tectono-stratigraphic evolution of rift systems with the observed crustal thinning and breakup processes.

How to cite: Chao, P., Manatschal, G., Kusznir, N., Chenin, P., Ren, J., and Pang, X.: The stratigraphic and magmatic tape recorder of crustal thinning and lithospheric breakup: insights from the NW South China Sea, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8920, https://doi.org/10.5194/egusphere-egu2020-8920, 2020