Continental collision and slab break-off: A comparison of 3-D numerical models with observations

Petrogenesis of the Early Eocene adakitic rocks in the Napuri area, southern Lhasa: Partial melting of thickened lower crust during slab break-off and implications for crustal thickening in southern Tibet

“…Here we use the slab break-off model to account for both the formation of the Napuri adakitic rocks and the associated magmatic "flare-up" event (e.g., Chung et al, 2005;Ji et al, 2009Ji et al, , 2012Lee et al, 2009Lee et al, , 2012Wen et al, 2008a;Zhu et al, 2011). When two continents collide, the tensile stresses between the buoyant continental lithosphere and previously subducted oceanic lithosphere lead to the separation of the oceanic slab from the continental lithosphere (e.g., Davies and von Blanckenburg, 1995;van Hunen and Allen, 2011;von Blanckenburg and Davis, 1995). Slab break-off typically occurs in the early stages of continental collisions (von Blanckenburg and Davis, 1995), and can place important constraints on associated collision dynamics (van Hunen and Allen, 2011).…”

“…When two continents collide, the tensile stresses between the buoyant continental lithosphere and previously subducted oceanic lithosphere lead to the separation of the oceanic slab from the continental lithosphere (e.g., Davies and von Blanckenburg, 1995;van Hunen and Allen, 2011;von Blanckenburg and Davis, 1995). Slab break-off typically occurs in the early stages of continental collisions (von Blanckenburg and Davis, 1995), and can place important constraints on associated collision dynamics (van Hunen and Allen, 2011). Timing and other details of the Neo-Tethyan slab break-off in the India-Asia collision belt have long been an issue of hot debate (e.g., Chung et al, 2005;Ji et al, 2009Ji et al, , 2012Lee et al, 2009Lee et al, , 2012Wen et al, 2008a;Xu et al, 2008;Zhu et al, 2013).…”

Slab breakoff: a causal mechanism or pure convenience?

“…It is possible that such increase and rise may indeed reflect more research that offers support or verification of the breakoff related interpretations, but it could also be a bandwagon effect because of the increasing popularity and convenience. While slab breakoff may indeed take place [6], and this could in some way facilitate magmatism and ease tectonic exhumation [7][8][9][10][11], we can readily see, however, that the effect of the "slab-breakoff" is likely overstretched in the current literature. Figure 2 shows a few examples from the literature that use slab-breakoff to explain geological observations.…”

Implementing nonlinear viscoplasticity in ASPECT: benchmarking and applications to 3D subduction modeling

“…Due to the increased interest in the process of slab tearing, it has recently been the subject of several numerical modeling studies (e.g. Gerya et al, 2004;Andrews and Billen, 2009;Billen, 2009, 2010;van Hunen and Allen, 2011;Duretz et al, 2012Duretz et al, , 2014. Numerical modeling of slab detachment is computationally 20 challenging due to the mesh-resolution dependency of the strain (van Hunen and Allen, 2011) and the gradual decrease in monitoring particle density, the gradual overlapping of level sets (Hillebrand et al, 2014), or the gradual thinning of compositional fields (as is the case here) in the detachment area.…”

“…To demonstrate ASPECT's promise in this field, we here present 3D models of free-plate intraoceanic subduction. Recent 3D subduction models have been applied in the study of along-strike effects such as oblique convergence (Malatesta et al, 2013), toroidal flow (Schellart and 10 Moresi, 2013), varying lithospheric structure (Mason et al, 2010;van Hunen and Allen, 2011;Capitanio and Faccenda, 2012;Duretz et al, 2014), slab width (Stegman et al, 2006;Schellart et al, 2007;Stegman et al, 2010) and the presence of lateral plates (Yamato et al, 2009). Four-dimensional (3D plus time) modeling allows us to investigate more realistically the generics of subduction (e.g.…”