Recent tectonic stress evolution in the Lesser Caucasus and adjacent regions

Abstract

The stress indicators describing the recent (provided by active tectonics framework) and palaeo-stress (provided by micro-fault kinematics and volcanic cluster) patterns show the scale and temporal changes in stress states since the beginning of Arabian–Eurasian collision. The recent stress derived from the active fault kinematics in the Lesser Caucasus and adjacent area corresponds to a strike–slip regime with both transtension and transpression characteristics. The kinematics of active structures of various scale are conditioned by tectonic stress field with general north–south compression and east–west extension. The distribution of Neogene to Quaternary volcanic cluster geometries and micro-fault kinematic data evidence the time and orientation variability of the stress field since the beginning of the Arabian–Eurasian collision. In addition to the general north–south compression orientation, two other – NW–SE and NE–SW – secondary orientations are observed. The first one was dominant between the Palaeogene and the late Early Miocene and the second one has prevailed between the Late Miocene and the Quaternary. Since the continental collision of Arabia with Eurasia the tectonic stress regime in the Lesser Caucasus and adjacent area changed from compression (thrusting and reverse faulting) to transtension-transpression (strike–slip faulting with various vertical components)

Relict basin closure and crustal shortening budgets during continental collision: An example from Caucasus sediment provenance

“…The modern structural architecture of active faults in the Lesser Caucasus is poorly understood, with north directed thrusting, south directed thrusting, and strike-slip faults all proposed as dominant structures [Koçyiğit et al, 2001;Philip et al, 1989;Rebaï et al, 1993]. More recent work argues for a strike-slip regime [Avagyan et al, 2010].…”

Neotectonic Deformation in Central Eurasia: A Geodynamic Model Approach

“…In north-west Iran, the northward subduction of the Neotethyan oceanic lithosphere beneath the Bitlis-Poturge massif (Rizaoglu et al, 2009;Sengör et al, 2003) formed the Eastern Anatolian accretionary complex (EAAC; Figure 1) and led to the onset of slip along the East Anatolia fault and the postcollisional volcanism in eastern Anatolia (Keskin, 2003). The North Anatolia fault zone formed in late Miocene-early Pliocene in response to a slab-detachment event (Faccenna et al, 2006), which is thought also to have modified the stress regime of the region, which changed from compression to transpression-transtension (Avagyan et al, 2010). The Caucasus range extends between the oceanic Journal of Geophysical Research: Solid Earth 10.1002/2017JB014487 rigid blocks of the Black Sea and Caspian Sea.…”

Linking the NE Anatolian and Lesser Caucasus ophiolites: evidence for large-scale obduction of oceanic crust and implications for the formation of the Lesser Caucasus-Pontides Arc

“…Zakariadze et al, 1990). More recent works along the Neotethys domain evidence processes which include Neotethyan oceanic crust obduction and the collision-accretion of microplates to the Eurasian margin before the final Arabia-Asia collision or IndiaAsia collision (Agard, Searle, Alsop, & Dubacq, 2010;Avagyan et al, 2010;De Sigoyer, Guillot, & Dick, 2004;Ding, Kapp, & Wan, 2005;Galoyan et al, 2009;Hacker, 1991;Hacker, Mosenfelder, & Gnos, 1996;Harper, Grady, & Coulton, 1996;Okay, Tansel, & Tüysüz, 2001;Rice, Robertson, & Ustaömer, 2009;Rolland et al, 2012;Rolland, Sosson, Adamia, & Sadradze, 2011;Searle & Cox, 1999;Sosson et al, 2010;Stampfli et al, 2001;Yılmaz, Yiğitbaş, & Can Genç, 1993). In these works, the presence of several geochemical suites in a given suture zone is interpreted as the tectonic collage of petrological slivers originating from various oceanic environments: volcanic arc, oceanic islands and seamounts, oceanic crust from mid oceanic ridge or from back-arcs.…”