Thermo-mechanical modeling of subduction of continental lithosphere

Sobouti, Farhad; Arkani‐Hamed, J.

doi:10.1016/s0031-9201(02)00064-x

Cited by 11 publications

(6 citation statements)

References 79 publications

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“…The crust of the upper plate is weak enough to be squeezed horizontally and allows for arrival of new crustal material to the subduction zone. Such displacement of the suture zone has been hinted in the previous numerical experiments of several authors [ Sobouti and Arkani‐Hamed , 2002; Willet and Beaumont , 1994; Ellis et al , 1998].…”

Section: A Step By Step Description Of the Experimentssupporting

confidence: 55%

Tectonic evolution of a continental collision zone: A thermomechanical numerical model

2004

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[1] We model evolution of a continent-continent collision and draw some parallels with the tectonic evolution of the Himalaya. We use a large-scale viscoplasto-elastic thermomechanical model that has a free upper surface, accounts for erosion and deposition and allows for all modes of lithospheric deformation. For quartz/olivine rheology and 60 mm/yr convergence rate, the continental subduction is stable, and the model predicts three distinct phases. During the phase 1 (120 km or 6% of shortening), deformation is characterized by back thrusting around the suture zone. Some amount of delaminated lower crust accumulates at depth. During phase 2 (120 km-420 km or 6%-22% of shortening), this crustal root is exhumed (medium-to high-grade rocks) along a newly formed major thrust fault. This stage bears similarities with the period of coeval activity of the Main Central thrust and of the South Tibetan Detachment between 20-16 Myr ago. During phase 3 (>420 km or 22% of shortening), the crust is scraped off from the mantle lithosphere and is incorporated into large crustal wedge. Deformation is localized around frontal thrust faults. This kinematics should produce only low-to medium-grade exhumation. This stage might be compared with the tectonics that has prevailed in the Himalaya over the last 15 Myr allowing for the formation of the Lesser Himalaya. The experiment is conducted at constant convergence rate, which implies increasing compressive force. Considering that this force is constant in nature, this result may be equivalent to a slowing down of the convergence rate as was observed during the India-Asia collision.

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Section: A Step By Step Description Of the Experimentssupporting

confidence: 55%

Tectonic evolution of a continental collision zone: A thermomechanical numerical model

2004

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“…By now, a large number of modeling studies have investigated various factors influencing subduction processes (e.g., Doin and Henry, 2001;Pysklywec et al, 2000;Sobouti and Arkani-Hamed, 2002;Chemenda et al, 1995;Gerya et al, 2002;Yamato et al, 2007Yamato et al, ,2008Warren et al, 2008a,b;Li and Gerya, 2009;Li et al, 2010;Sizova et al, 2012;Gray and Pysklywec, 2010;2012). However, not all of the existing models are sufficiently consistent.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

“…The numerical models are often limited by simplified visco-plastic rheologies or by the rigid top/"sticky air" upper-boundary condition, which is widely used instead of the paramount free-surface boundary condition. The use of rigid-top upper-boundary condition forces stable subduction (Doin and Henry, 2001;Sobouti and Arkani-Hamed, 2002), attenuates pure shear, cancels folding and does not allow for consistent prediction of topography evolution. Many models also do not incorporate surface processes which are key forcing factors of…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Rheological and geodynamic controls on the mechanisms of subduction and HP/UHP exhumation of crustal rocks during continental collision: Insights from numerical models

et al. 2014

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International audienceWhile subduction of crustal rocks is increasingly accepted as a common scenario inherent to convergent processes involving continental plates and micro-continents, its occurrence in each particular context, as well as its specific mechanisms and conditions is still debated. The presence of ultra-high pressure(UHP) terranes is often interpreted as a strong evidence for continental subduction (subduction of continental crust) since the latter is seen as the most viable mechanism of their burial to UHP depths, yet if one admits nearly lithostatic pressure conditions in the subduction interface (or "channel"). The presumed links of continental subduction to exhumation of high- and ultra-high-pressure (HP/UHP) units also remain a subject of controversy despite the fact that recent physically consistent thermo-mechanical numerical models of convergent processes suggest that subduction can create specific mechanisms for UHP exhumation. We hence review and explore possible scenarios of subduction of continental crust, and their relation to exhumation of HP and UHP rocks as inferred from last generation of thermo-mechanical numerical models accounting for thermo-rheological complexity and structural diversity of the continental lithosphere. The inferences from these models are matched with the petrology data, in particular, with P-T-t paths, allowing for better understanding of subtleties of both subduction and burial/exhumation mechanisms. Numerical models suggest that exhumation and continental subduction are widespread but usually transient processes that last for less than 5-10 Myr, while long-lasting (> 10-15 Myr) subduction can take place only in rare cases of fast convergence of cold strong lithospheres (e.g. India). The models also show that tectonic heritage can play a special role in subduction/exhumation processes. In particular, when thicker continental terrains are embedded in subducting oceanic plate, exhumation of UHP terranes results in the formation of versatile metamorphic belts and domes and in series of slab roll-back and exhumation events with remarkably different P-T-t records

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“…In previous studies, buoyancy (Ranalli et al 2000; Sobouti & Arkani‐Hamed 2002), rheological properties of the continental and oceanic material (strength, temperature; Wong A Tong & Wortel 1997; van de Zedde & Wortel 2001; Sobouti & Arkani‐Hamed 2002; Li & Liao 2002; Toussaint et al 2004), subduction velocity (Davies & von Blanckenburg 1995; Li & Liao 2002; Toussaint et al 2004; Burov & Yamato 2007) and interplate pressure (Chemenda et al 1996) have been indicated as the main variables controlling the evolution of continental collision. In our study, we took a step in direction of establishing which are the parameters that dominate the behaviour of continental collision during the initial stage of the process, and we do not study the entire evolution of it.…”

Section: A Link Between Short and Long Timescale Continental Collismentioning

confidence: 99%

“…Alternatively, the continental lithosphere thickens until it drips into the deeper mantle as a result of a Rayleigh–Taylor thermal instability (Houseman et al 1981; Houseman & Molnar 1997; Pysklywec et al 2000, 2002). Whether and at which depth slab break‐off occurs is a function of temperature and convergence velocity (Davies & von Blanckenburg 1995; Wong A Tong & Wortel 1997; Sobouti & Arkani‐Hamed 2002; Toussaint et al 2004). Strong slabs preserve their integrity against the increase of the integrated crustal buoyancy with the amount of subducted crust.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of continental collision: influence of the plate contact

Franco

Govers

Wortel

2008

Geophysical Journal International

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S U M M A R YObservations shows that continental collision may evolve in different ways, resulting in a wide range of tectonic responses. In search of the controlling conditions and parameters, we start from the results of our previous work, which demonstrated that the properties of the plate contact are important for the overall dynamics of convergent plate margins. Two fundamental types of subduction plate contact can be distinguished: one based on a fault and the other based on a weak subduction channel. In this study, we investigate how the plate contact affects the initial stage of continental collision. We use a finite element method to solve the heat and the time-dependent momentum equations for elastic, (power-law) viscous and plastic rheologies. For the same rheological properties and driving forces, varying the nature of the plate contact leads to three types of responses. The presence of a subduction channel promotes coherent and, when the boundary conditions allow it, plate-like subduction of the continental margin. In models with a subduction fault, coherent subduction of the incoming continental lithosphere occurs when the colliding passive margin has a gentle slope. The approaching continental sliver starts to subduct and the subduction is characterized by a non-plate like behaviour-slower subduction velocity than in channel models and strong slab deformation. If the continental margin is steep and the strength of the incoming continental crust is high, fault models result in locking of the trench, eventually leading to slab break-off. If the crustal strength is relatively low, shear delamination of part of the crust is expected. In the channel model, this type of delamination never occurs. The tectonic settings used in our experiments (prescribed plate velocity of the subducting plate versus fixed subducting plate corresponding to a landlocked basin setting) do not significantly influence the nature of the model response. We conclude that initial stages of continental collision are strongly affected by whether the subduction contact is a fault or a channel. Neither the slab pull magnitude nor the tectonic setting is very important to the overall geodynamics at this stage. The plate contact type, along with the slope of the incoming passive margin and the rheology of the continent, controls whether the incoming crust (1) subducts entirely; (2) separates partially or entirely from the lithospheric mantle or (3) blocks the trench, likely leading to slab break-off.

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Thermo-mechanical modeling of subduction of continental lithosphere

Cited by 11 publications

References 79 publications

Tectonic evolution of a continental collision zone: A thermomechanical numerical model

Tectonic evolution of a continental collision zone: A thermomechanical numerical model

Rheological and geodynamic controls on the mechanisms of subduction and HP/UHP exhumation of crustal rocks during continental collision: Insights from numerical models

Dynamics of continental collision: influence of the plate contact

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