The role of deep subduction in supercontinent breakup

Luca Dal Zilio, Manuele Faccenda, Fabio Capitanio

Research output: Contribution to journalArticleResearchpeer-review

12 Citations (Scopus)

Abstract

The breakup of continents and their subsequent drifting plays a crucial role in the Earth's periodic plate aggregation and dispersal cycles. While continental aggregation is considered the result of oceanic closure during subduction, what drives sustained divergence in the following stages remains poorly understood. In this study, thermo-mechanical numerical experiments illustrate the single contribution of subduction and coupled mantle flow to the rifting and drifting of continents. We quantify the drag exerted by subduction-induced mantle flow along the basal surface of continental plates, comparing models of lithospheric slab stagnation above the upper-lower mantle boundary with those where slabs penetrate into the lower mantle. When subduction is upper-mantle confined, divergent basal tractions localise at distances comparable to the effective upper mantle thickness (~. 500. km), causing the opening of a marginal basin. Instead, subduction of lithosphere in the lower mantle reorganises the flow into a much wider cell localising extensional stresses at greater distances from the trench (~. 3000. km). Sub-continental tractions are higher and more sustained over longer time periods in this case, and progressively increase as the slab sinks deeper. Although relatively low, basal-shear stresses when integrated over large plates, generate tension forces that may exceed the strength of the continental lithosphere, eventually leading to breakup and opening of a distal basin. The models illustrate the emergence of a similar mechanism, which results in the formation of back-arc basins above upper-mantle confined subduction, and scales to much larger distances for deeper subduction. Examples include the Atlantic Ocean formation and drifting of the South and North American plates during the Mesozoic-Cenozoic Farallon plate subduction.

Original languageEnglish
Pages (from-to)312-324
Number of pages13
JournalTectonophysics
Volume746
DOIs
Publication statusPublished - 2018

Keywords

  • Geodynamic
  • Numerical modeling
  • Plate tectonics
  • Subduction
  • Subduction-induced mantle flow
  • Supercontinent breakup

Cite this

Dal Zilio, Luca ; Faccenda, Manuele ; Capitanio, Fabio. / The role of deep subduction in supercontinent breakup. In: Tectonophysics. 2018 ; Vol. 746. pp. 312-324.
@article{fe750e3276194671beb0535be9e37ae4,
title = "The role of deep subduction in supercontinent breakup",
abstract = "The breakup of continents and their subsequent drifting plays a crucial role in the Earth's periodic plate aggregation and dispersal cycles. While continental aggregation is considered the result of oceanic closure during subduction, what drives sustained divergence in the following stages remains poorly understood. In this study, thermo-mechanical numerical experiments illustrate the single contribution of subduction and coupled mantle flow to the rifting and drifting of continents. We quantify the drag exerted by subduction-induced mantle flow along the basal surface of continental plates, comparing models of lithospheric slab stagnation above the upper-lower mantle boundary with those where slabs penetrate into the lower mantle. When subduction is upper-mantle confined, divergent basal tractions localise at distances comparable to the effective upper mantle thickness (~. 500. km), causing the opening of a marginal basin. Instead, subduction of lithosphere in the lower mantle reorganises the flow into a much wider cell localising extensional stresses at greater distances from the trench (~. 3000. km). Sub-continental tractions are higher and more sustained over longer time periods in this case, and progressively increase as the slab sinks deeper. Although relatively low, basal-shear stresses when integrated over large plates, generate tension forces that may exceed the strength of the continental lithosphere, eventually leading to breakup and opening of a distal basin. The models illustrate the emergence of a similar mechanism, which results in the formation of back-arc basins above upper-mantle confined subduction, and scales to much larger distances for deeper subduction. Examples include the Atlantic Ocean formation and drifting of the South and North American plates during the Mesozoic-Cenozoic Farallon plate subduction.",
keywords = "Geodynamic, Numerical modeling, Plate tectonics, Subduction, Subduction-induced mantle flow, Supercontinent breakup",
author = "{Dal Zilio}, Luca and Manuele Faccenda and Fabio Capitanio",
year = "2018",
doi = "10.1016/j.tecto.2017.03.006",
language = "English",
volume = "746",
pages = "312--324",
journal = "Tectonophysics",
issn = "0040-1951",
publisher = "Elsevier",

}

The role of deep subduction in supercontinent breakup. / Dal Zilio, Luca; Faccenda, Manuele; Capitanio, Fabio.

In: Tectonophysics, Vol. 746, 2018, p. 312-324.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - The role of deep subduction in supercontinent breakup

AU - Dal Zilio, Luca

AU - Faccenda, Manuele

AU - Capitanio, Fabio

PY - 2018

Y1 - 2018

N2 - The breakup of continents and their subsequent drifting plays a crucial role in the Earth's periodic plate aggregation and dispersal cycles. While continental aggregation is considered the result of oceanic closure during subduction, what drives sustained divergence in the following stages remains poorly understood. In this study, thermo-mechanical numerical experiments illustrate the single contribution of subduction and coupled mantle flow to the rifting and drifting of continents. We quantify the drag exerted by subduction-induced mantle flow along the basal surface of continental plates, comparing models of lithospheric slab stagnation above the upper-lower mantle boundary with those where slabs penetrate into the lower mantle. When subduction is upper-mantle confined, divergent basal tractions localise at distances comparable to the effective upper mantle thickness (~. 500. km), causing the opening of a marginal basin. Instead, subduction of lithosphere in the lower mantle reorganises the flow into a much wider cell localising extensional stresses at greater distances from the trench (~. 3000. km). Sub-continental tractions are higher and more sustained over longer time periods in this case, and progressively increase as the slab sinks deeper. Although relatively low, basal-shear stresses when integrated over large plates, generate tension forces that may exceed the strength of the continental lithosphere, eventually leading to breakup and opening of a distal basin. The models illustrate the emergence of a similar mechanism, which results in the formation of back-arc basins above upper-mantle confined subduction, and scales to much larger distances for deeper subduction. Examples include the Atlantic Ocean formation and drifting of the South and North American plates during the Mesozoic-Cenozoic Farallon plate subduction.

AB - The breakup of continents and their subsequent drifting plays a crucial role in the Earth's periodic plate aggregation and dispersal cycles. While continental aggregation is considered the result of oceanic closure during subduction, what drives sustained divergence in the following stages remains poorly understood. In this study, thermo-mechanical numerical experiments illustrate the single contribution of subduction and coupled mantle flow to the rifting and drifting of continents. We quantify the drag exerted by subduction-induced mantle flow along the basal surface of continental plates, comparing models of lithospheric slab stagnation above the upper-lower mantle boundary with those where slabs penetrate into the lower mantle. When subduction is upper-mantle confined, divergent basal tractions localise at distances comparable to the effective upper mantle thickness (~. 500. km), causing the opening of a marginal basin. Instead, subduction of lithosphere in the lower mantle reorganises the flow into a much wider cell localising extensional stresses at greater distances from the trench (~. 3000. km). Sub-continental tractions are higher and more sustained over longer time periods in this case, and progressively increase as the slab sinks deeper. Although relatively low, basal-shear stresses when integrated over large plates, generate tension forces that may exceed the strength of the continental lithosphere, eventually leading to breakup and opening of a distal basin. The models illustrate the emergence of a similar mechanism, which results in the formation of back-arc basins above upper-mantle confined subduction, and scales to much larger distances for deeper subduction. Examples include the Atlantic Ocean formation and drifting of the South and North American plates during the Mesozoic-Cenozoic Farallon plate subduction.

KW - Geodynamic

KW - Numerical modeling

KW - Plate tectonics

KW - Subduction

KW - Subduction-induced mantle flow

KW - Supercontinent breakup

UR - http://www.scopus.com/inward/record.url?scp=85015993750&partnerID=8YFLogxK

U2 - 10.1016/j.tecto.2017.03.006

DO - 10.1016/j.tecto.2017.03.006

M3 - Article

VL - 746

SP - 312

EP - 324

JO - Tectonophysics

JF - Tectonophysics

SN - 0040-1951

ER -