Neoproterozoic plate tectonic process and Phanerozoic geodynamic evolution of the South China Block

Liangshu Shu (1) , Jinlong Yao (2) , Bo Wang (1) , Michel Faure (3, 4) , Jacques Charvet (3, 4) , Yan Chen (3, 4)

1 NJU - Nanjing University
2 Northwest University (Xi'an)
3 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
4 Géodynamique - UMR7327

The South China Block is situated in the Eastern Asian margin. Since the Neoproterozoic, its tectonic evolution was constrained by successive consumption-closure processes of the Paleo-South China, Proto-Tethys, Paleo-Tethys, and Paleo-Pacific oceans. Studies suggest that this block was initially formed by the Neoproterozoic assembly of the Yangtze and Cathaysia blocks following the subduction-accretion of the Paleo-South China Ocean. Then after, it experienced three tectonic-magmatic events in the Phanerozoic. Among these events, the Late Mesozoic tectonism-magmatism was linked with the consumption of the Paleo-Pacific Ocean, while the Silurian and Early to Middle Triassic events took place in intracontinental settings that were related to far-field effects of the closure of the remote Proto-Tethys and Paleo-Tethys oceans, respectively. The subduction-accretion of the Paleo-South China Ocean, and collision at 980–820 Ma between the Yangtze and Cathaysia blocks formed the Jiangnan Orogenic Belt and the Proto-South China Continent, followed by a rifting tectonics and bimodal volcanism at 810–760 Ma. From 760 Ma to 460 Ma, the South China Block was situated under shore, shallow sea to slope depositional environments. During Late Ordovician to Early Devonian (460–400 Ma), an intracontinental orogeny occurred mainly in the Cathaysia Block as a response to the closure of the Proto-Tethys Ocean. Shortly afterwards, this block underwent a stable carbonate deposition during Early Devonian- Middle Triassic (400–230 Ma) and was thus under a shore or shallow sea environment. In the Middle-Late Triassic (240–220 Ma), the South China Block was affected by the closure of the Paleo-Tethys Ocean, intracontinental deformation and S-type granitic magmatism. During the Cretaceous, a multi-stage basin-and-range framework occurred in the western shore of the Paleo-Pacific Plate.

Mots clés: Neoproterozoic Paleo-South China Ocean; Proto-Tethys Ocean; Paleo-Tethys Ocean; Paleo-Pacific Ocean; Subduction and accretion; Far-field effects of plate collisio; South China Block

Domaines: Planète et Univers [physics]; Sciences de la Terre

Liangshu Shu, Jinlong Yao, Bo Wang, Michel Faure, Jacques Charvet, et al.. Neoproterozoic plate tectonic process and Phanerozoic geodynamic evolution of the South China Block. Earth-Science Reviews, 2021, pp.103596. ⟨10.1016/j.earscirev.2021.103596⟩. ⟨insu-03169133⟩