Non–Equilibrium Plate Kinematics since the Late Triassic

Antonio Schettino (a)
(a) School of Science & Technology, University of Camerino, Camerino, Italy. E-mail: antonio.schettino@unicam.it

I present evidence for up to eight episodes of non–equilibrium plate kinematics since the Mesozoic. These episodes, which were associated with unbalancing between plate boundary torques and basal drag exerted by the asthenosphere, resulted into accelerated plate motion of individual plates, accompanied in some cases by extensive plume magmatism, although there is no evidence for active plume head pushes. The phases of accelerated motion almost always consisted into increasing velocity relative to the Earth’s spin axis, which was accompanied by higher subduction rate at the frontal boundary of the corresponding plate, although some episodes of plate deceleration are also observed.

Plate kinematics, Mantle geodynamics, Mesozoic and Cenozoic plate motions