Palaeozoic collision between the North and South China Blocks, Triassic intracontinental tectonics, and the problem of the ultrahigh-pressure metamorphism

Michel Faure (1) , Wei Lin (2) , Patrick Monié (3) , Sébastien Meffre (4)

1 ISTO - Institut des Sciences de la Terre d'Orléans
2 IGG - Institute of Geology and Geophysics [Beijing]
3 Géosciences Montpellier
4 School of Earth Sciences [Hobart]

The Qinling–Dabie Belt represents the boundary between the North and South China Blocks (NCB, SCB, respectively), where ultrahigh-pressure (UHP) rocks are widespread. A structural study in eastern Qinling and zircon LA ICPMS dating of the migmatite that form the core of the Central Qinling Unit allows us to argue that continental collision occurred in Silurian, before 400 Ma. In the Late Palaeozoic, from Devonian to Permian, the northern margin of SCB experienced a continental rifting. From Late Permian to Middle Triassic, northward continental subduction of SCB is responsible for the development of a high-pressure metamorphism. The age of the UHP metamorphism remains unsettled yet. A two-time genesis, Early Palaeozoic and Early Triassic, is often preferred, but a single Palaeozoic age followed by a Triassic resetting cannot be ruled out.

Mots clés: Qinling–Dabie Belt; Palaeozoic collision; Triassic tectonics; Continental subduction; Ultrahigh-pressure metamorphism

Domaines: Tectonique; Milieux et Changements globaux

Michel Faure, Wei Lin, Patrick Monié, Sébastien Meffre. Palaeozoic collision between the North and South China Blocks, Triassic intracontinental tectonics, and the problem of the ultrahigh-pressure metamorphism. Comptes Rendus Géoscience, 2008, 340, pp.139-150. ⟨10.1016/j.crte.2007.10.007⟩. ⟨insu-00191534⟩