Potential role of strain hardening in the cessation of rifting at constant tectonic force

Tadashi Yamasaki, Randell Stephenson

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

In this study the cessation of rifting at constant tectonic force is discussed from the viewpoint of lithospheric rheology using a simple one-dimensional numerical model. The behaviour of the conventionally adopted constant force model re-examined in this study contradicts some general features in the development of sedimentary basins. Strain hardening is implemented to explain the contradictions, in which the viscosity of the mantle is a function of not only the strain rate and temperature but also the total strain. The roles of various strain hardening parameters in rifting dynamics are examined, including the strain required for the onset of hardening, the strain interval required for the completion of hardening and the factor controlling the increase in mantle viscosity. It is shown that a model with strain hardening can explain many characteristic features of sedimentary basin formation better than the conventional constant force model. There are a variety of ways in which rifting can be terminated by the strain hardening model, depending oil the initial lithospheric structure, magnitude of tectonic force and the hardening process. one possible strain hardening mechanism involves the switch from wet to dry rheology associated with decompressional melting, though the implemented strain hardening formula could be generally applicable to any hardening phenomenon and could therefore be physically interpreted as such. The results of this Study also provide important insights into sedimentary basin subsidence in relation to rifting dynamics. The end of an initial rapid ("syn-rift" like) subsidence phase is not necessarily equivalent to the end of actual rifting as in the constant force model. The transition from initial rapid subsidence to long-term, more Subdued ("post-rift" like), subsidence is actually marked by the onset of deceleration of rifting. Since significant extension still continues for some time thereafter. the subsequent long-term subsidence includes some mechanical effect of crustal thinning. (c) 2008 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)47-62
Number of pages16
JournalJournal of Geodynamics
Volume47
Issue number1
Early online date17 Jul 2008
DOIs
Publication statusPublished - Jan 2009

Keywords

  • rifting
  • strain rate
  • stretching factor
  • tectonic subsidence
  • strain hardening
  • tectonic force
  • Asymmetric lithospheric extension
  • olivine single-crystals
  • continental lithosphere
  • sedimentary basins
  • dynamic recrystallization
  • laboratory experiments
  • relative importance
  • phase-transitions
  • crustal structure
  • upper-mantle

Cite this

Potential role of strain hardening in the cessation of rifting at constant tectonic force. / Yamasaki, Tadashi; Stephenson, Randell.

In: Journal of Geodynamics, Vol. 47, No. 1, 01.2009, p. 47-62.

Research output: Contribution to journalArticle

@article{424dde4439524a968695ddf222ff50a4,
title = "Potential role of strain hardening in the cessation of rifting at constant tectonic force",
abstract = "In this study the cessation of rifting at constant tectonic force is discussed from the viewpoint of lithospheric rheology using a simple one-dimensional numerical model. The behaviour of the conventionally adopted constant force model re-examined in this study contradicts some general features in the development of sedimentary basins. Strain hardening is implemented to explain the contradictions, in which the viscosity of the mantle is a function of not only the strain rate and temperature but also the total strain. The roles of various strain hardening parameters in rifting dynamics are examined, including the strain required for the onset of hardening, the strain interval required for the completion of hardening and the factor controlling the increase in mantle viscosity. It is shown that a model with strain hardening can explain many characteristic features of sedimentary basin formation better than the conventional constant force model. There are a variety of ways in which rifting can be terminated by the strain hardening model, depending oil the initial lithospheric structure, magnitude of tectonic force and the hardening process. one possible strain hardening mechanism involves the switch from wet to dry rheology associated with decompressional melting, though the implemented strain hardening formula could be generally applicable to any hardening phenomenon and could therefore be physically interpreted as such. The results of this Study also provide important insights into sedimentary basin subsidence in relation to rifting dynamics. The end of an initial rapid ({"}syn-rift{"} like) subsidence phase is not necessarily equivalent to the end of actual rifting as in the constant force model. The transition from initial rapid subsidence to long-term, more Subdued ({"}post-rift{"} like), subsidence is actually marked by the onset of deceleration of rifting. Since significant extension still continues for some time thereafter. the subsequent long-term subsidence includes some mechanical effect of crustal thinning. (c) 2008 Elsevier Ltd. All rights reserved.",
keywords = "rifting, strain rate, stretching factor, tectonic subsidence, strain hardening, tectonic force, Asymmetric lithospheric extension, olivine single-crystals, continental lithosphere, sedimentary basins, dynamic recrystallization, laboratory experiments, relative importance, phase-transitions, crustal structure, upper-mantle",
author = "Tadashi Yamasaki and Randell Stephenson",
year = "2009",
month = "1",
doi = "10.1016/j.jog.2008.07.001",
language = "English",
volume = "47",
pages = "47--62",
journal = "Journal of Geodynamics",
issn = "0264-3707",
publisher = "Elsevier Limited",
number = "1",

}

TY - JOUR

T1 - Potential role of strain hardening in the cessation of rifting at constant tectonic force

AU - Yamasaki, Tadashi

AU - Stephenson, Randell

PY - 2009/1

Y1 - 2009/1

N2 - In this study the cessation of rifting at constant tectonic force is discussed from the viewpoint of lithospheric rheology using a simple one-dimensional numerical model. The behaviour of the conventionally adopted constant force model re-examined in this study contradicts some general features in the development of sedimentary basins. Strain hardening is implemented to explain the contradictions, in which the viscosity of the mantle is a function of not only the strain rate and temperature but also the total strain. The roles of various strain hardening parameters in rifting dynamics are examined, including the strain required for the onset of hardening, the strain interval required for the completion of hardening and the factor controlling the increase in mantle viscosity. It is shown that a model with strain hardening can explain many characteristic features of sedimentary basin formation better than the conventional constant force model. There are a variety of ways in which rifting can be terminated by the strain hardening model, depending oil the initial lithospheric structure, magnitude of tectonic force and the hardening process. one possible strain hardening mechanism involves the switch from wet to dry rheology associated with decompressional melting, though the implemented strain hardening formula could be generally applicable to any hardening phenomenon and could therefore be physically interpreted as such. The results of this Study also provide important insights into sedimentary basin subsidence in relation to rifting dynamics. The end of an initial rapid ("syn-rift" like) subsidence phase is not necessarily equivalent to the end of actual rifting as in the constant force model. The transition from initial rapid subsidence to long-term, more Subdued ("post-rift" like), subsidence is actually marked by the onset of deceleration of rifting. Since significant extension still continues for some time thereafter. the subsequent long-term subsidence includes some mechanical effect of crustal thinning. (c) 2008 Elsevier Ltd. All rights reserved.

AB - In this study the cessation of rifting at constant tectonic force is discussed from the viewpoint of lithospheric rheology using a simple one-dimensional numerical model. The behaviour of the conventionally adopted constant force model re-examined in this study contradicts some general features in the development of sedimentary basins. Strain hardening is implemented to explain the contradictions, in which the viscosity of the mantle is a function of not only the strain rate and temperature but also the total strain. The roles of various strain hardening parameters in rifting dynamics are examined, including the strain required for the onset of hardening, the strain interval required for the completion of hardening and the factor controlling the increase in mantle viscosity. It is shown that a model with strain hardening can explain many characteristic features of sedimentary basin formation better than the conventional constant force model. There are a variety of ways in which rifting can be terminated by the strain hardening model, depending oil the initial lithospheric structure, magnitude of tectonic force and the hardening process. one possible strain hardening mechanism involves the switch from wet to dry rheology associated with decompressional melting, though the implemented strain hardening formula could be generally applicable to any hardening phenomenon and could therefore be physically interpreted as such. The results of this Study also provide important insights into sedimentary basin subsidence in relation to rifting dynamics. The end of an initial rapid ("syn-rift" like) subsidence phase is not necessarily equivalent to the end of actual rifting as in the constant force model. The transition from initial rapid subsidence to long-term, more Subdued ("post-rift" like), subsidence is actually marked by the onset of deceleration of rifting. Since significant extension still continues for some time thereafter. the subsequent long-term subsidence includes some mechanical effect of crustal thinning. (c) 2008 Elsevier Ltd. All rights reserved.

KW - rifting

KW - strain rate

KW - stretching factor

KW - tectonic subsidence

KW - strain hardening

KW - tectonic force

KW - Asymmetric lithospheric extension

KW - olivine single-crystals

KW - continental lithosphere

KW - sedimentary basins

KW - dynamic recrystallization

KW - laboratory experiments

KW - relative importance

KW - phase-transitions

KW - crustal structure

KW - upper-mantle

U2 - 10.1016/j.jog.2008.07.001

DO - 10.1016/j.jog.2008.07.001

M3 - Article

VL - 47

SP - 47

EP - 62

JO - Journal of Geodynamics

JF - Journal of Geodynamics

SN - 0264-3707

IS - 1

ER -