Mode of crustal extension determined by rheological layering

Wijns, Chris; Weinberg, Roberto Ferrez; Gessner, Klaus; Moresi, Louis

doi:10.1016/j.epsl.2005.05.030

Cited by 76 publications

(70 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spacing between individual shear zones and the width of associated basins results from a dynamic interplay involving the brittle-ductile transition depth in the upper crust (e.g. Vendeville et al 1987), the strength contrast between upper and lower crust (Wijns et al 2005) and the lithospheric necking width. For example, the deeper brittle-ductile transition depth in the thick-lithosphere model at 1 My and 8 My (Fig.…”

Section: Alternative Model Setups and Robustness Of Resultsmentioning

confidence: 99%

The rift to break-up evolution of the Gulf of Aden: Insights from 3D numerical lithospheric-scale modelling

Brune

Autin

2013

Tectonophysics

View full text Add to dashboard Cite

The Gulf of Aden displays an ideal setting to study oblique rifting since numerous structural data are available onshore and offshore. Recent surveys showed that the spatio-temporal evolution of the Gulf of Aden rift system is dominated by three fault orientations: displacement-orthogonal (WSW), rift-parallel (WNW) and a direction that is intermediate between both of them (W). The oldest parts of the rift that are exposed onshore feature displacement-orthogonal and intermediate directions, whereas the subsequently active necking zone involves mainly rift-parallel faults. The final rift phase that is recorded at the distal margin is characterised by displacement-orthogonal and intermediate azimuths. We investigate the Gulf of Aden evolution from rift initiation to breakup by means of 3D numerical experiments on lithospheric scale. We apply the finite element model SLIM3D which includes realistic elasto-visco-plastic rheology and a free surface. Despite recent advances, 3D numerical experiments still require relatively coarse resolution so that individual faults are poorly resolved. We address this issue by proposing a simple post-processing method that uses the surface stress-tensor to evaluate stress regime (extensional, strike-slip, compressional) and preferred fault azimuth. The described method is applicable to any geodynamic model and easy to introduce. Our model reproduces the observed fault pattern of the Gulf of Aden and illustrates how multiple fault directions arise from the interaction of local and far-field tectonic stresses in an evolving rift system. The numerical simulations robustly feature intermediate faults during the initial rift phase, followed by rift-parallel normal faulting at the rift flanks and strike-slip faults in the central part of the rift system. Upon break-up, displacementorthogonal as well as intermediate faults occur. This study corroborates and extends findings from previous analogue experiments of oblique rifting on lithospheric scale and allows new insights in the timing of fault successions of the Gulf of Aden and continental rifts in general.

show abstract

Section: Alternative Model Setups and Robustness Of Resultsmentioning

confidence: 99%

The rift to break-up evolution of the Gulf of Aden: Insights from 3D numerical lithospheric-scale modelling

Brune

Autin

2013

Tectonophysics

View full text Add to dashboard Cite

show abstract

“…Patterns (or modes) of continental extension primarily depend on the rheological layering of the lithosphere (Analytical models: Buck, 1991;Analogue models: Allemand and Brun, 1991;Brun, 1999;Tirel et al, 2006;Numerical models: Lavier et al, 1999;2000;Tirel et al, 2004a;Wijns et al, 2005;Gessner et al, 2007;Gueydan et al, 2008;Rey et al, 2009a;2009b;Huet et al, 2011;Wang et al, 2015;Wu et al, 2015;Wu & Lavier, 2016). For a general appraisal of lithosphere rheology and its effects on large-scale geodynamics see Burov (2007a;2010;.…”

Section: Modes Of Extension As a Function Of Lithosphere Rheologymentioning

confidence: 99%

“…Different types of perturbations in the initial conditions are used to localize the deformation at model centre such as: fault in the brittle crust (2), low viscosity anomaly in the ductile crust (4), local cohesion loss (2) or local higher cohesion (1) in the brittle layer, thermal anomaly in the lower crust or in the mantle and wedge shape crust. In models with no perturbation (Wijns et al, 2005;Gessner et al, 2007;Tirel et al, 2009) deformation is more distributed leading to the simultaneous development of several core complexes that can interfere during their development (Tirel et al, 2009). In addition, in 11 models a strain weakening function is used in brittle and/or ductile material.…”

Section: Comparison Of With Other Numerical Modelsmentioning

confidence: 99%

“…In models that integrate phase transitions controlled by pressure, temperature and the local amount of free fluid that comes from both external (meteoric) and local (dehydration) sources show a strong positive feedback between the asymmetry of the tectonic structures and the depth of penetration of meteoric fluids. From a general point of view, it must be noted that all models involving some type of strain softening favor asymmetric strain localization and the development of a rolling hinge type detachment, even in models where displacements are applied symmetrically and whatever the type of localizing perturbation (Lavier et al, 1999;2000;Lavier and Buck, 2002;Wijns et al, 2005;Gessner et al, 2007;Rey et al, 2009a;2009b;Tirel et al, 2009;Mezri et al, 2015;Schenker et al, 2012;Wang et al, 2015;Wu et al, 2015;Wu and Lavier, 2015). This suggests that strain softening could play a dominant role in the development of detachments and therefore in the evolution of core complex models.…”

Section: Comparison Of With Other Numerical Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Crustal versus mantle core complexes

et al. 2018

View full text Add to dashboard Cite

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Contrary to what is commonly believed, it is argued from analogue and numerical models that detachments that accommodate exhumation of core complexes do not initiate at the onset of extension but in the course of progressive extension when the exhuming ductile crust reaches the surface. In models, convex upward detachments result from a rolling hinge process. A C C E P T E D M A N U S C R I P TMantle core complexes develop in either the oceanic lithosphere, at slow and ultra-slow spreading ridges, or in continental lithospheres, whose initial Moho temperature is lower than 750°C, with "sub-Moho mantle-dominated" strength profiles. It is argued that the mechanism of mantle exhumation at passive margins is a nearly symmetrical necking process at ACCEPTED MANUSCRIPTA C C E P T E D M A N U S C R I P T 2 lithosphere scale without major and permanent detachment, except if strong strain localization could occur in the lithosphere mantle. Distributed crustal extension, by upper crust faulting above a décollement along the ductile crust increases toward the rift axis up to crustal breakup.Mantle rocks exhume in the zone of crustal breakup accommodated by conjugate mantle shear zones that migrate with the rift axis, during increasing extension.

show abstract

“…Formation of these different types has been found to depend on factors such as extension rate, strain softening, thickness of the brittle crust and strength of the ductile crust, and processes associated with extension, as, for example, gravitationally driven deformation, isostasy, magmatism and necking [Buck, 1991;Buck et al, 1999;Benes and Davy, 1996;Lavier et al, 2000;Corti et al, 2003;Lizarralde et al, 2007]. The numerical models of Wijns et al [2005] and Moresi and Mühlhaus [2007] show progressively more distributed faulting in the brittle upper crust (a wide rift mode) for an increase in strength of the ductile lower crust or a decrease in strength of the brittle upper crust. A decreasing fault or necking spacing with increasing substrate strength also results from the instability analyzes of Montési and Zuber [2003] and Fletcher and Hallet [1983].…”

Section: Introductionmentioning

confidence: 99%

Dissipation analysis as a guide to mode selection during crustal extension and implications for the styles of sedimentary basins

2008

View full text Add to dashboard Cite

[1] We analyze the initial modes of continental extension with the aim of providing an improved understanding of the dynamic development of sedimentary basins. We first examine simple two-layer crustal-scale models which consist of a frictional-plastic upper crust bonded to a linear viscous lower crust of equal thickness. The mode of deformation is predicted by using an analytical analysis of the rate of internal dissipation of energy and the gravitational rate of work. It is assumed that models deform in the mode in which the total rate of work is minimized. For strain-softening models we predict the following modes of crustal extension: (1) pure shear, (2) multiple conjugate or parallel shear zones, (3) two shear zones, which form either one symmetric basin or two asymmetric basins, and (4) a single shear zone forming an asymmetric basin. The transitions between these modes are shown to depend on the trade off between ''gains'' that reduce the rate of energy dissipation and ''penalties'' that increase it. A single asymmetric basin is preferred for a strong brittle layer which has a high amount of strain softening (high plastic gain), a weak viscous layer and slow extension (low viscous penalty). A decrease in the plastic gain and/or an increase in the viscous penalty leads to modes with more shear zones in the upper crust. The pure shear mode is found for low strain softening, a high viscosity, and/or fast extension. Results of finite element calculations of equivalent simple two-layer models agree with the analytical mode predictions.Citation: Buiter, S. J. H., R. S. Huismans, and C. Beaumont (2008), Dissipation analysis as a guide to mode selection during crustal extension and implications for the styles of sedimentary basins,

show abstract

Mode of crustal extension determined by rheological layering

Cited by 76 publications

References 43 publications

The rift to break-up evolution of the Gulf of Aden: Insights from 3D numerical lithospheric-scale modelling

The rift to break-up evolution of the Gulf of Aden: Insights from 3D numerical lithospheric-scale modelling

Crustal versus mantle core complexes

Dissipation analysis as a guide to mode selection during crustal extension and implications for the styles of sedimentary basins

Contact Info

Product

Resources

About