Indo-Atlantic plate accelerations around the Cretaceous-Paleogene boundary: A time-scale error, not a plume-push signal - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Geology Année : 2020

Indo-Atlantic plate accelerations around the Cretaceous-Paleogene boundary: A time-scale error, not a plume-push signal

L. Pérez-Díaz
  • Fonction : Auteur
K. Sigloch

Résumé

Abstract It has been suggested that plume arrival at the base of the lithosphere introduces a push force that overwhelms the balance of torques driving plate circuits, leading to plate-tectonic reorganizations. Among the most compelling evidence in support of a “plume-push” mechanism is the apparent coincidence between eruption of the Deccan flood basalts around 67–64 Ma and a short-lived increase in Indian (and decrease in African) plate speed. Using existing and newly calculated high-resolution plate-motion models, we show that plate divergence rates briefly increased throughout the Indo-Atlantic circuit, contrary to the expected effects of plume-push. We propose that this circuit-wide spike in divergence rates is best explained as the artifact of a magnetic reversal time-scale error around the much studied Cretaceous-Tertiary boundary, and that the period spanning chrons C29–C28 lasted 70% longer than currently assumed. Corrected for this error, the residual long-term patterns of Indo-Atlantic plate motions and accompanying plate-tectonic reorganization are explicable in terms of maturation of the circuit’s spreading ridges, without invoking a significant plume-push force.
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Dates et versions

hal-03425543 , version 1 (23-11-2021)

Identifiants

Citer

L. Pérez-Díaz, G. Eagles, K. Sigloch. Indo-Atlantic plate accelerations around the Cretaceous-Paleogene boundary: A time-scale error, not a plume-push signal. Geology, 2020, 48 (12), pp.1169-1173. ⟨10.1130/G47859.1⟩. ⟨hal-03425543⟩
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