Cenozoic-Recent tectonics and uplift in the Greater Caucasus: a perspective from Azerbaijan

The Greater Caucasus is Europe’s highest mountain belt and results from the inversion of the Greater Caucasus back-arc-type basin due to the collision of Arabia and Eurasia. The orogenic processes that led to the present mountain chainstarted in the Early Cenozoic, accelerated during the Plio-Pleistocene, and are still active as shown from present GPS studies and earthquake distribution. The Greater Caucasus is a doubly verging fold-and- thrust belt, with a proand a retro wedge actively propagating into the foreland sedimentary basinof the Kura to the south and the Terek to the north, respectively. Based on tectonic geomorphology – active and abandoned thrust fronts – the mountain rangecan be subdivided into several zones with different uplift amounts and rates with very heterogeneous strain partitioning. The central part of the mountain range– defined by the Main Caucasus Thrust to the south and backthrusts to the north – forms a triangular-shape zone showing the highest uplift and fastest rates, and is due to thrusting over a steep tectonic ramp system at depth. The meridional orogenic in front of the Greater Caucasus in Azerbaijan lies at the foothillsof the Lesser Caucasus, to the south of the Kura foreland basin. The Caucasus orogen lies at Europe’s cross-road with Asia and Arabia, and is one of the world’s outstanding mountain ranges(Fig. 1). It is Europe’s highest mountain rangewith Mount Elbrus culminating at 5642 m a.s.l. in the western Greater Caucasus. It consists of the Greater Caucasus (GC), intramontane basins (Kura-Kartli-Rioni; c. 200 m elevation) and the Lesser Caucasus. North of the Greater Caucasus the deep sedimentary Terek and Kuban foreland basin(.6000 m thick; up to 1600 m elevation) form the transition to the Scythian platform. NNW of Mount Elbrus, the Stavropol ‘high’ forms a basement uplift, and in the east the northern slope is formed by the Dagestan foreland fold-and- thrust belt. The southern Greater Caucasus foreland, SW of Tbilisi is one of the world’s earliest sites of human society with 1.8 Ma old hominoid remains of Dmanisi (Georgia) (Lordkipanidze et al. 2007). The Lesser Caucasus with lower topography (c. 3000 m), is a zone of important volcanic and seismic activity. In the east and west, the Caucasus topography is bound by two very deep sedimentary basins, the South Caspian Sea and the Black Sea, hosting some of the world’s largest oil and gas provinces. The Caucasus orogen is caused by the north directed movement of the Arabian plate squeezing a Jurassic to Early Palaeogene subduction related volcanic arc(Lesser Caucasus) as well as Jurassic to Pliocene marine sedimentary rocks and sediments (northern Lesser Caucasus, substratum of KuraKartli Basins and Greater Caucasus Basin) towards the Scythian plate (Gamkrelidze 1986; Nikishin et al. 2001; Stampfli et al. 2001; Popov et al. 2004; Hafkenscheid et al. 2006; Kazmin & Tikhonova 2006; Sosson et al. 2010). Recent plate tectonic models and GPS-based convergence rates (Gamkrelidze & Kuloshvili 1998; Vernant et al. 2004; Reilinger et al. 2006; Kadirov et al. 2008) suggest a moderate anticlockwise rotational 1 Published in ! which should be cited to refer to this work. ht tp :// do c. re ro .c h