Lateral propagation-induced subduction initiation at passive continental margins controlled by preexisting lithospheric weakness.
Sci Adv
; 6(10): eaaz1048, 2020 Mar.
Article
en En
| MEDLINE
| ID: mdl-32181357
ABSTRACT
Understanding the conditions for forming new subduction zones at passive continental margins is important for understanding plate tectonics and the Wilson cycle. Previous models of subduction initiation (SI) at passive margins generally ignore effects due to the lateral transition from oceanic to continental lithosphere. Here, we use three-dimensional numerical models to study the possibility of propagating convergent plate margins from preexisting intraoceanic subduction zones along passive margins [subduction propagation (SP)]. Three possible regimes are achieved (i) subducting slab tearing along a STEP fault, (ii) lateral propagation-induced SI at passive margin, and (iii) aborted SI with slab break-off. Passive margin SP requires a significant preexisting lithospheric weakness and a strong slab pull from neighboring subduction zones. The Atlantic passive margin to the north of Lesser Antilles could experience SP if it has a notable lithospheric weakness. In contrast, the Scotia subduction zone in the Southern Atlantic will most likely not propagate laterally.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Sci Adv
Año:
2020
Tipo del documento:
Article
País de afiliación:
China