Influence of magma-poor versus magma-rich passive margins on subduction initiation - Archive ouverte HAL Access content directly
Journal Articles Gondwana Research Year : 2022

Influence of magma-poor versus magma-rich passive margins on subduction initiation

(1) , (2, 3) , (4, 2) , (1) , (1) , (5, 1)
1
2
3
4
5

Abstract

We present a new numerical modelling study of subduction initiation at (hyper-extended) magma-poor and magma-rich continental passive margins. In particular, we test how the structure and rheological stratification of these two end-member types control the formation and thermo-mechanical evolution of subduction zones. The serpentinization of mantle lithosphere in a magma-poor continental rifted margin leads to rheological decoupling at the base of the continental crust, which induces shear localization during subsequent shortening. Under these conditions, a shear zone propagates into the mantle lithosphere and leads to subduction initiation at the transition between ocean and passive margin. In contrast, a magma-rich rifted continental margin is rheologically coupled, which creates a buttressing effect and transfer of deformation into the oceanic domain during shortening, where the subduction zone initiates. These results are quantitatively compared and in agreement with the geological record of subduction initiation in the Alps and Dinarides – Hellenides, where the relics of end-member types of continental rifted margins of the same Adriatic micro-continent bordering the Alpine Tethys and Neotethys oceans, respectively, are observed.
Fichier principal
Vignette du fichier
auzemery-2021.pdf (5.94 Mo) Télécharger le fichier
Origin : Files produced by the author(s)

Dates and versions

insu-03460417 , version 1 (01-12-2021)

Identifiers

Cite

Antoine Auzemery, Philippe Yamato, Thibault Duretz, E. Willingshofer, L. Matenco, et al.. Influence of magma-poor versus magma-rich passive margins on subduction initiation. Gondwana Research, 2022, 103, pp.172-186. ⟨10.1016/j.gr.2021.11.012⟩. ⟨insu-03460417⟩
54 View
46 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More