India‐Asia collision and the Cenozoic slowdown of the Indian plate: Implications for the forces driving plate motions - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research : Solid Earth Année : 2010

India‐Asia collision and the Cenozoic slowdown of the Indian plate: Implications for the forces driving plate motions

Jean-Philippe Avouac
Jean-Yves Royer

Résumé

The plate motion of India changed dramatically between 50 and 35 Ma, with the rate of convergence between India and Asia dropping from ∼15 to ∼4 cm/yr. This change is coincident with the onset of the India‐Asia collision, and with a rearrangement of plate boundaries in the Indian Ocean. On the basis of a simple model for the forces exerted upon the edges of the plate and the tractions on the base of the plate, we perform force balance calculations for the precollision and postcollision configurations. We show that the observed Euler poles for the Indian plate are well explained in terms of their locations and magnitudes if (1) the resistive force induced by mountain building in the Himalaya‐Tibet area is ∼5–6 × 1012 N/m, (2) the net force exerted upon the Indian plate by subduction zones is similar in magnitude to the ridge‐push force (∼2.5 × 1012 N/m), and (3) basal tractions exert a resisting force that is linearly proportional to the plate velocity in the hot spot reference frame. The third point implies an asthenospheric viscosity of ∼2–5 × 1019 Pa s, assuming a thickness of 100–150 km. Synthetic Euler poles show that crustal thickening in the Tibetan Plateau was the dominant cause of the Cenozoic slowdown of the Indian plate.
Fichier principal
Vignette du fichier
JGR-Copley-Royer-2010.pdf (525.92 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

insu-00563237 , version 1 (07-02-2011)

Identifiants

Citer

Alex Copley, Jean-Philippe Avouac, Jean-Yves Royer. India‐Asia collision and the Cenozoic slowdown of the Indian plate: Implications for the forces driving plate motions. Journal of Geophysical Research : Solid Earth, 2010, 115, pp.B03410. ⟨10.1029/2009JB006634⟩. ⟨insu-00563237⟩
232 Consultations
526 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More