Ancient Continental Lithosphere Dislocated Beneath Ocean Basins Along the Mid-Lithosphere Discontinuity: A Hypothesis

Zhensheng Wang, Timothy M. Kusky, Fabio A. Capitanio

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

The documented occurrence of ancient continental cratonic roots beneath several oceanic basins remains poorly explained by the plate tectonic paradigm. These roots are found beneath some ocean-continent boundaries, on the trailing sides of some continents, extending for hundreds of kilometers or farther into oceanic basins. We postulate that these cratonic roots were left behind during plate motion, by differential shearing along the seismically imaged mid-lithosphere discontinuity (MLD), and then emplaced beneath the ocean-continent boundary. Here we use numerical models of cratons with realistic crustal rheologies drifting at observed plate velocities to support the idea that the mid-lithosphere weak layer fostered the decoupling and offset of the African continent's buoyant cratonic root, which was left behind during Meso-Cenozoic continental drift and emplaced beneath the Atlantic Ocean. We show that in some cratonic areas, the MLD plays a similar role as the lithosphere-asthenosphere boundary for accommodating lateral plate tectonic displacements.

Original languageEnglish
Pages (from-to)9253-9260
Number of pages8
JournalGeophysical Research Letters
Volume44
Issue number18
DOIs
Publication statusPublished - 28 Sep 2017

Keywords

  • continental drift
  • cratonic root
  • mid-lithosphere discontinuity
  • oceanic basins
  • oceanic plateau
  • plate tectonics

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