Slab Folding and Surface Deformation of the Iran Mobile Belt

Abstract

Back-arc systems record compressional and/or extensional deformation pulses lasting for a few tens of millions of years (e.g., Clark et al., 2008). This episodic and ephemeral style of upper-plate deformation has been documented in back-arc basins around the Western Pacific (e.g.,

Magnetostratigraphic Age Control of the Timing of Tectonic Deformation and the Shifting Depositional Environments in the Dezful Embayment, Iran

“…In Central Iran, the last marine transgression was suggested to be diachronous (Mohammadi et al., 2013), the marine conditions started from the southeast in the Rupelian (early Oligocene) and continued northwestwards to the Qom back‐arc basin in the late Oligocene to early Miocene. This late Oligocene‐early Miocene marine transgression was attributed to extensional or transtensional deformation phase occurred in the Central Iranian Domain (Boutoux et al., 2021; Morley et al., 2009). The final marine regression from Central Iran in the Qom basin was at the late Burdigalian (Reuter et al., 2009) or a magnetostratigraphic age of 17 Ma (Sun, Talebian, et al., 2021) driven by the Arabia‐Eurasia collision (Reuter et al., 2009; Sun, Talebian, et al., 2021).…”

The Role of Lithospheric‐Deep Mantle Interactions on the Style and Stress Evolution of Arc‐Continent Collision

“…In our simulations, lithospheric extension and thinning are driven only by the dissipation of gravitational potential energy stored in the deformed orogen and is unrelated to back‐arc extension produced by either trench‐kinematics or slab roll‐back in older (>70 Myr) slabs. We acknowledge that contributions such as intermediate angle slab‐folding events (backwards slab‐folding; Boutoux et al., 2021) and plate‐trench kinematics (Chen et al., 2016; Schellart & Moresi, 2013) are important, and widely known mechanisms that explain extension in the overriding continental plate. However, the geodynamic conditions that emerge from our numerical simulations, reproduce a scenario where these mechanisms are unable to drive lithospheric thinning in the continental plate in the absence of a colliding arc (Figure 5).…”

“…Our results show that the coupling of lithospheric flow driven by the mechanical properties of accreted intra-oceanic arcs and episodes of slab-folding, provide a new mechanism that explains surface and lithospheric extension in accretionary continental margins, where the migration of the trench is limited by slab-anchoring in the MTZ and/or the strength of the overriding plate. An example of this is the closure of the Neo-Tethys ocean basin, a >10,000 km subduction zone (Ali et al, 2014(Ali et al, , 2016Bonnet et al, 2020;Bosch et al, 2011;Mitchell et al, 1993), where arc-continent collision, transient strain-stress regimes and the interaction of the subducting slab with the MTZ have been documented by geological and seismic tomography studies (Ali et al, 2012(Ali et al, , 2014(Ali et al, , 2016Boutoux et al, 2021;Jolivet et al, 2016). Moreover, since subduction, mantle flow, and lithospheric deformation emerge entirely from buoyancy forces in our numerical simulations, we are able to offer a new viewpoint that focuses on how the gravitational spreading of the orogen and lithospheric flow controls the post-collisional evolution of arc-continent collision.…”

Morphoevolution of the Seymareh landslide-dam lake system (Zagros Mountains, Iran): Implications for Holocene climate and environmental changes

“…The Seymareh drainage basin (Fig. 1) is located within the northwestern part of the Zagros belt, which resulted from the collision of continental blocks of Arabia and Eurasia and the consequent consumption of the Neotethys since the late Cretaceous (Boutoux et al, 2021;McQuarrie, 2004;Mouthereau et al, 2012;Stampfli and Borel, 2002;Talbot and Alavi, 1996). Its drainage network dissects most of the Lorestan region (e.g., Vergés et al, 2011), crossing several tectonic units of the mountain range, which are oriented from NE to SW: the Sanandaj-Sirjan Zone (SSZ), the High Zagros zone (HZ, named also Imbricate zone), the Simply Folded Belt (SFB) and the continental Mesopotamian Foreland (Agard et al, 2005, and references therein).…”