Planation surfaces of the Tian Shan Range (Central Asia): Insight on several 100 million years of topographic evolution

Abstract

In Central Asia, numerous fragments of planation surfaces are visible within the present day topography. However, their precise timing of formations is still poorly constrained and it is not clear if they are remnants of a single extensive planation surface or if they represent different planation episodes. By reconstructing the landscape evolution of the Tian Shan region and by analyzing the relations between the planation surfaces preserved within the eastern Tarim Basin and the sedimentary record, we demonstrate that the numerous erosional surfaces preserved within the Tian Shan Range represent different episodes of surfaces genesis. These erosion events span from the late Paleozoic to the Early Cenozoic. The widespread preservation of large fragments of these surfaces within the Tian Shan Range implies that this region did not undergo strong relief building during most of its Mesozoic evolution but was dominated by plains associated to small hills along episodically active discrete tectonic structures. Finally, the preservation of these surfaces within the active Tian Shan Range implies a long-term, strong non-equilibrium state of the topography during its Cenozoic evolution. This was probably promoted by the arid to semi-arid climate prevailing since the Late Paleogene onset of relief building.

Thermochronology of the highest central Asian massifs (Khan Tengri - Pobedi, SE Kyrgyztan): Evidence for Late Miocene (ca. 8 Ma) reactivation of Permian faults and insights into building the Tian Shan

“…Bullen et al, 2003Bullen et al, , 2001Jolivet et al, 2010;Macaulay et al, 2014). This long period of tectonic quiescence is also supported by the formation of large peneplains and alluvial fans in western Central Asia (Hendrix et al, 1992;Dumitru et al, 2001;Jolivet et al, 2007Jolivet et al, , 2009Jolivet et al, , 2015Vassallo et al, 2007;Jolivet, 2015;Morin et al, 2019).…”

“…Following the pioneering works of Afonichev and Vlasov (1984); Makarov (1977); Chediya (1986); Hendrix et al (1992) and Dumitru et al (2001) during most of the Jurassic (e.g. Dumitru et al, 2001;Sobel et al, 2006a;Jolivet et al, 2010;De Grave et al, 2011Tang et al, 2015;Glorie and De Grave, 2016;Zhang et al, 2016;Gillespie et al, 2017a-b;Wang et al, 2017;Morin et al, 2019). The Permian-Cretaceous peneplain is recognized in the landscape in regions neighbouring the Pobedi range; therefore, in these areas, Cenozoic tectonics have resulted in surface uplift with very limited erosion.…”

“…4, 5). The age of this tectonic transport is indirectly constrained by 40 Ar/ 39 Ar biotite ages between 265-256 Ma, which suggests a rapid cooling of the Pobedi granulites after the metamorphic (Rolland et al 2013;Konopelko et al 2013;Morin et al, 2019), with up to 70 km of right-lateral slip in the Permian-Triassic (Alexeiev et al, 2017). During this phase of transcurrent deformation, the Tarim Basin experienced a significant phase of subsidence (Carroll et al 1995).…”

Towards interactive global paleogeographic maps, new reconstructions at 60, 40 and 20 Ma

“…Rohrmann et al, 2012;Van Der Beek et al, 2009;Wang et al, 2008). In northern Tibet, no major deformation is reported before the collision apart from local events possibly reactivating older structures (Jolivet et al, 2018;Morin et al, 2019;Van Hinsbergen et al, 2015).…”

Late Pleistocene Uniform Rate of Thrusting Along the Fault's Strike: A Case Study From the Northern Tian Shan Foreland

“…As one of the largest and most active orogenic belts in Central Asia, the Tian Shan has experienced a complex history of geological evolution (e.g., Allen et al., 1991; Bullen et al., 2001, 2003; A. Yin, Nie, et al., 1998). The ancient Tian Shan was formed during Late Paleozoic (Windley et al., 1990), and since then has experienced strong erosion and planation during Late Mesozoic‐Early Cenozoic, resulting in beveling of the topography of the range and formation of a vast peneplain (Allen et al., 1991; Bullen et al., 2003; Morin et al., 2019). In response to the ongoing India‐Asia collision since the Early Cenozoic (Avouac & Tapponnier, 1993; Najman et al., 2001; Tapponnier et al., 2001), the Tian Shan has been tectonically reactivated and has propagated into its foreland basins (Zhang, 2004).…”