General map of the larger Caucasus area with topography and earthquake distribution. Not all existing thrusts are shown only a selection of the major thrusts of the Greater Caucasus relevant for the discussion. Transparent red indicates the pre-Mesozoic core. Yellow highlighted area is the Adjara-Trialet fold-and-thrust-belt. Black triangles are mountain summits of the Greater Caucasus, black stars correspond to localities cited in text. 

Contexts in source publication

Context 1

... Kura- Kartli and also the Rioni foreland basins are dissected by, and incorporated into, the outward propagating foreland FTB to the south of the main range. Deep seated southward migration of the orogenic front led to the inversion of the Pliocene to Late Pleistocene sediments, and the transport of the Alasani basin (Figs 1 & 3a) as a piggy back basin towards the south. ...

Context 2

... the axial zone of the Greater Caucasus comprises Jurassic sedimentary rocks (Azerbaijan), a pre-Mesozoic basement (Georgia, Russia), and Pliocene intrusions, both external fold-and-thrust Fig. 2. General crustal-scale cross-section through the eastern Greater Caucasus and the Lesser Caucasus (location see Fig. 1). The Lesser Caucasus is associated with a northward subduction and possibly a detached slab [based on tomography after Hafkenscheid et al. (2006)]. No subduction is seen under the Greater Caucasus. The Greater Caucasus is a doubly verging orogenic wedge with the dominant thrusting towards the pro-wedge to the South. A retro-foreland ...

Context 3

... Greater Caucasus is a doubly verging orogenic wedge with the dominant thrusting towards the pro-wedge to the South. A retro-foreland fold-and-thrust belt develops to the north in Dagestan (Russia) see also Figure 1. Three different types of crust have been distinguished according to their geodynamic belonging: to the South a crust intruded and associated with the Jurassic- Cretaceous suprasubduction arc volcanism in the Lesser Caucasus, in the centre the thinned and rifted and intruded southern part of the supra-subduction backarc basin, and to the north the northern part of this extended backarc rift system with the important Mesozoic sedimentary series of the Greater Caucasus Basin. ...

Context 4

... (1986). Some recent papers ( Kadirov et al. 2008) mistakenly label the thrust separating the Alasani Basin from the terrains in higher topographic elevations to the north as MCT. This latter thrust is believed to be a relic thrust front of early Cenozoic age. In eastern Azer- baijan, east of Mount Bazardüzü (the highest summit in Azerbaijan, Fig. 1), we lose the trace of the MCT and fieldwork has shown that is relayed by a string of fault-related ...

Context 5

... Greater and Lesser Caucasus are seismically active zones linked to the rapid and non-uniform plate convergence between Arabia and Eurasia ( Philip et al. 1989;Jackson 1992;Priestley et al. 1994;Triep et al. 1995;Jackson et al. 2002;Allen et al. 2004Allen et al. , 2006) (Fig. 1). The Lesser Caucasus and the adjoining Anatolian Plateau show a predo- minance of strike-slip focal mechanisms associated with a system of vertical faults. In the Greater Cau- casus, on the contrary, convergence is accommo- dated predominantly by reverse focal mechanisms associated to thrusting with a general north-south to NE-SW ...

Context 6

... faults are located to the south and are structurally in the footwall of the MCT. To the west this fault system links to the MCT precisely where this latter shows an important bend, and is stepping back (to the north) into the mountain range (Figs 1 & 3a, b). We suggest that the MCT is developing a new splay, and that the higher seismicity in this region is due this propagation of the MCT to the SW and to a lower structural level (Fig. 3a). ...

Context 7

... existence of several levels and ages of river terraces document continued incision possibly due to uplift of the mountain range (Shirinov 1973). This is also shown by the important cliffs of Quaternary material cannibalized on the northern slopes of the eastern Greater Caucasus near Quba (Figs 1 & 4) (Kangarli 1982). Connecting these 'events' to the different levels and ages of terraces along the (a) Uplift rates: map shows that highest rates of 10-12 mm a 21 are found in the central part of the western Greater Caucasus ( Philip et al. 1989). ...

Context 8

... to the south the Quaternary sediments of the northern part of the Kura-Kartli basin are folded and thrusted. Very prominent in the morphology the Karamarian Quaternary Anticline in Azerbaijan (Girdimanchai River -city of Agsu; (Figs 1 & 7) is a large doubly plunging anticline showing well developed water gaps formed by tributaries of the river Girdimanchai (Fig. 7) (Shirinov 1975). A large asymmetric south-verging anticline is devel- oped over a blind thrust with splays. ...

Context 9

... Cenozoic, but mainly affect the southern parts of the basin (Sosson et al. 2010). Volcanoclastic series derived from the Lesser Caucasus volcanic arc are now found imbri- cated and folded in the southern foothills of the Greater Caucasus where they form distinct tectono- sedimentary units (Kangarli 1982, 2005). In situ intrusives remain however rare and are associated with igneous activity on the margins to the south of the Greater Caucasus Basin (Mengel et al. 1987; Mustafayev 2001; Chalot-Prat et al. 2007). Pliocene to Quaternary igneous activity is observed in the central part of the mountain range, in the border areas between Georgia and Russia (Tchechenia). The most outstanding examples are Mount Elbrus with 5642 m a.s.l. and further East Mount Kazbek (5047 m a.s.l.). These intrusions are mainly late-collisional, subalkaline granitoids that roughly range between 4.5 and 1.5 Ma (Hess et al. 1993; Gazis et al. 1995; Nosova et al. 2005; Lebedev & Bubnov 2006), and culminate with Quaternary volcanism reaching into the Holocene (Lebedev 2005; Chernyshev et al. 2006). Several successive tectonic events are documented in the Greater Caucasus sedimentary record. Precambrian and Palaeozoic (pre-Hercynian and Hercynian) tectonic phases are recorded in the pre- Alpine basement or Palaeozoic core (for discussion and references see Gamkrelidze & Shengelia 2005; Kazmin 2006; Saintot et al. 2006 a , b ; Somin et al. 2006) and are followed by palaeotectonic events related to the Tethyan oceans (Palaeo- and Neo- tethys) (Nikishin et al. 1997; Barrier et al. 2008). These palaeotectonic events included extensional structures recorded throughout the Mesozoic cover of the Greater Caucasus Basin (Dotduyev 1986), but also unconformities thought to result from compressive phases such as the ‘Eo-Cimmerian’ (Triassic) and the ‘Mid-Cimmerian’ (Callovian – Bajocian) which is well documented in northern Azerbaijan (Fig. 4). The link of the latter unconformity to possible orogenic events remains speculative and debated. The geometry of the Greater Caucasus sedimentary basin is of passive margin type with numerous tilted blocks. The central part of the orogen – where the oldest series outcrop, and topography is the highest – represents a distal basin between a platform domain to the north and a distant deeper domain with a structural high (tilted block) to the south. The foreland basins associated with the orogenic evolution are filled with Cenozoic and Quaternary sediments. In the south they build on top of the former distal, stretched continental margin (Greater Caucasus Basin), in the north they build on a flexural foreland underlain by a carbonate platform (Ershov et al. 1999). During the growth of the orogen since the Early Cenozoic the thrust front is propagating out into its own foreland basins. Especially the southern basins develop into a succession of piggy- back foreland basins, subsequently and progress- ively abandoned (relic thrust fronts) as the orogenic front migrates southward. A typical example of an abandoned basin is the Cenozoic–Quaternary Alasani Basin (Philip et al. 1989) (Figs 1 & 3a). Distinct tectonic zones, from north to south, are separated by major thrusts (Dotduyev 1986). They correspond to the original palaeogeographic setup and build upon inherited, pre-existing structures (Egan et al. 2009). Lateral correlations and differences can be made between the western region in Crimea (Saintot et al. 1998; Saintot & Angelier 2000; Saintot et al. 2006 a ), through Georgia (Gamkrelidze & Rubinstein 1974; Gamkrelidze & Gamkrelidze 1977; Banks et al. 1997) to the Caspian Sea (Kangarli 1982, 2005; Allen et al. 2003; Egan et al. 2009). The Adjara-Trialet FTB in Georgia located to the south of the southern limit of the Greater Caucasus in Georgia (Banks et al. 1997; Gudjabidze 2003) is of particular interest since thrusting is top to the North, opposite the direction in the GC (Gamkrelidze & Kuloshvili 1998). One of the major structural features in the GC is the Main Caucasus Thrust (MCT) (Dotduyev 1986). This large thrust can be observed along strike of the mountain belt over a distance of more than 1000 km (Figs 5 & 3). Displacement on this major thrust fault is top to the South, possibly in excess of 30 km in some places. In the west in Russia and Georgia, the MCT separates the Palaeozoic metamorphic core of the mountain range from the Jurassic cover series to the South. Further east in Georgia, Dagestan (Russia) and Azerbaijan it is found in the core of the orogen, separating rocks of different Jurassic ages. The definition of the MCT used here is according to Dotduyev (1986). Some recent papers (Kadirov et al. 2008) mistakenly label the thrust separating the Alasani Basin from the terrains in higher topographic elevations to the north as MCT. This latter thrust is believed to be a relic thrust front of early Cenozoic age. In eastern Azerbaijan, east of Mount Bazard ̈z ̈ (the highest summit in Azerbaijan, Fig. 1), we lose the trace of the MCT and fieldwork has shown that is relayed by a string of fault-related folds. The Greater and Lesser Caucasus are seismically active zones linked to the rapid and non-uniform plate convergence between Arabia and Eurasia (Philip et al. 1989; Jackson 1992; Priestley et al. 1994; Triep et al. 1995; Jackson et al. 2002; Allen et al. 2004, 2006) (Fig. 1). The Lesser Caucasus and the adjoining Anatolian Plateau show a predo- minance of strike–slip focal mechanisms associated with a system of vertical faults. In the Greater Caucasus, on the contrary, convergence is accommodated predominantly by reverse focal mechanisms associated to thrusting with a general north–south to NE–SW compression (Ko ̧yigit et al. 2001; Barazangi et al. 2006; Copley & Jackson 2006; Tan & Taymaz 2006), see also discussion in (Jackson 1992; Allen et al. 2004). Slip vectors based on earthquake focal mechanisms show a general top-to-the-south thrusting. Strike – slip mechanisms exist but are rare. Present seismicity is unevenly distributed across the GC (Figs 1 & 3). A zone with a higher seismic activity is observed on the south slope of the Greater Caucasus west of Tbilisi (Georgia) in the Racha area (Triep et al. 1995). Studies of focal mechanisms and focal depths show that this seismicity is linked to several active fault strings in the subsurface of the Gagra-Dzhava zone (Triep et al. 1995; Gamkrelidze & Kuloshvili 1998). They show south directed slip vectors. These faults are located to the south and are structurally in the footwall of the MCT. To the west this fault system links to the MCT precisely where this latter shows an important bend, and is stepping back (to the north) into the mountain range (Figs 1 & 3a, b). We suggest that the MCT is developing a new splay, and that the higher seismicity in this region is due this propagation of the MCT to the SW and to a lower structural level (Fig. 3a). To the east this fault system may be correlated with the thrust fault at the front of the Alasani Basin. It is relevant to notice that elsewhere in the Greater Caucasus the largest earthquakes known (earthquakes . magnitude 6, both historical and measured) are all located in the vicinity of the MCT. We interpret this to show the importance of the MCT to the present day in the deformation processes, since large earthquakes occur along large faults accommodating important displacement. The MCT appears to be a major thrust in the development of the Greater Caucasus. Seismicity is extending into the Middle and South Caspian Sea (Kovachev et al. 2006). In the Apsheron zone focal mechanisms show NNE– SSW oriented thrusting (Jackson et al. 2002) and seismic activity may be linked with an extension / termination of the Greater Caucasus towards the East and / or with young north-directed subduction of the South Caspian Basin to the North under the Apsheron (Allen et al. 2002; Knapp et al. 2004). The seismicity further south as well as in the Gobustan desert area shows a westward component of motion relative to Eurasia, suggesting underthrusting towards the west (Jackson et al. 2002). Some seismic activity is also seen in the central part of the eastern Greater Caucasus, as well as in the Kura basin. On the northern slopes, the Dagestan FTB and the recent faults in the Terek Basin show a higher concentration of earthquakes pointing to active thrust tectonics in this area. Studies on palaeoseismology remain rare but confirm the existence of inherited faults and the possible 2000 year recurrence of high magnitude events (Rogozin et al. 2002; Rogozin & Ovsyuchenko 2005). Studies based on GPS technologies in the larger Caucasus area, including Turkey, Arabia and Iran have confirmed the global picture of convergence across the Caucasus (McClusky et al. 2000; Nilforoushan et al. 2003; Reilinger et al. 2006). The average convergence of Arabia and Eurasia of 18 –23 mm a 2 1 is transformed into a deformation of 14 mm a 2 1 with a north–south direction across the Greater Caucasus, mainly the southern part (Vernant et al. 2004). Detailed studies in Azerbaijan (Kadirov et al. 2008) confirm a rotational convergence between Arabian and European plates. Shortening is distributed between the Northern Kura Basin and the outermost thrusts of the Dagestan FTB. Present-day slip rates decrease from 10 + 1 mm a 2 1 in eastern Azerbaijan to 4 + 1 mm a 2 1 in western Azerbaijan (Kadirov et al. 2008). A similar study in Georgia shows the opposite thrust directions between south-dipping thrusts in the Adjara-Trialet FTB and the Greater Caucasus front, which shows relative motion of 6.9 + 1.1 mm a 2 1 to the SW on north-dipping thrusts (Gamkrelidze & Kuloshvili 1998). These studies also show a marked change (decrease) in velocities across the MCT. Indeed north of the MCT velocities are almost 0, indicating no longi- tudinal displacement. All deformation appears to be taken up in uplift. Across the more or less north –south oriented ...

Context 10

... activity on the margins to the south of the Greater Caucasus Basin (Mengel et al. 1987; Mustafayev 2001; Chalot-Prat et al. 2007). Pliocene to Quaternary igneous activity is observed in the central part of the mountain range, in the border areas between Georgia and Russia (Tchechenia). The most outstanding examples are Mount Elbrus with 5642 m a.s.l. and further East Mount Kazbek (5047 m a.s.l.). These intrusions are mainly late-collisional, subalkaline granitoids that roughly range between 4.5 and 1.5 Ma (Hess et al. 1993; Gazis et al. 1995; Nosova et al. 2005; Lebedev & Bubnov 2006), and culminate with Quaternary volcanism reaching into the Holocene (Lebedev 2005; Chernyshev et al. 2006). Several successive tectonic events are documented in the Greater Caucasus sedimentary record. Precambrian and Palaeozoic (pre-Hercynian and Hercynian) tectonic phases are recorded in the pre- Alpine basement or Palaeozoic core (for discussion and references see Gamkrelidze & Shengelia 2005; Kazmin 2006; Saintot et al. 2006 a , b ; Somin et al. 2006) and are followed by palaeotectonic events related to the Tethyan oceans (Palaeo- and Neo- tethys) (Nikishin et al. 1997; Barrier et al. 2008). These palaeotectonic events included extensional structures recorded throughout the Mesozoic cover of the Greater Caucasus Basin (Dotduyev 1986), but also unconformities thought to result from compressive phases such as the ‘Eo-Cimmerian’ (Triassic) and the ‘Mid-Cimmerian’ (Callovian – Bajocian) which is well documented in northern Azerbaijan (Fig. 4). The link of the latter unconformity to possible orogenic events remains speculative and debated. The geometry of the Greater Caucasus sedimentary basin is of passive margin type with numerous tilted blocks. The central part of the orogen – where the oldest series outcrop, and topography is the highest – represents a distal basin between a platform domain to the north and a distant deeper domain with a structural high (tilted block) to the south. The foreland basins associated with the orogenic evolution are filled with Cenozoic and Quaternary sediments. In the south they build on top of the former distal, stretched continental margin (Greater Caucasus Basin), in the north they build on a flexural foreland underlain by a carbonate platform (Ershov et al. 1999). During the growth of the orogen since the Early Cenozoic the thrust front is propagating out into its own foreland basins. Especially the southern basins develop into a succession of piggy- back foreland basins, subsequently and progress- ively abandoned (relic thrust fronts) as the orogenic front migrates southward. A typical example of an abandoned basin is the Cenozoic–Quaternary Alasani Basin (Philip et al. 1989) (Figs 1 & 3a). Distinct tectonic zones, from north to south, are separated by major thrusts (Dotduyev 1986). They correspond to the original palaeogeographic setup and build upon inherited, pre-existing structures (Egan et al. 2009). Lateral correlations and differences can be made between the western region in Crimea (Saintot et al. 1998; Saintot & Angelier 2000; Saintot et al. 2006 a ), through Georgia (Gamkrelidze & Rubinstein 1974; Gamkrelidze & Gamkrelidze 1977; Banks et al. 1997) to the Caspian Sea (Kangarli 1982, 2005; Allen et al. 2003; Egan et al. 2009). The Adjara-Trialet FTB in Georgia located to the south of the southern limit of the Greater Caucasus in Georgia (Banks et al. 1997; Gudjabidze 2003) is of particular interest since thrusting is top to the North, opposite the direction in the GC (Gamkrelidze & Kuloshvili 1998). One of the major structural features in the GC is the Main Caucasus Thrust (MCT) (Dotduyev 1986). This large thrust can be observed along strike of the mountain belt over a distance of more than 1000 km (Figs 5 & 3). Displacement on this major thrust fault is top to the South, possibly in excess of 30 km in some places. In the west in Russia and Georgia, the MCT separates the Palaeozoic metamorphic core of the mountain range from the Jurassic cover series to the South. Further east in Georgia, Dagestan (Russia) and Azerbaijan it is found in the core of the orogen, separating rocks of different Jurassic ages. The definition of the MCT used here is according to Dotduyev (1986). Some recent papers (Kadirov et al. 2008) mistakenly label the thrust separating the Alasani Basin from the terrains in higher topographic elevations to the north as MCT. This latter thrust is believed to be a relic thrust front of early Cenozoic age. In eastern Azerbaijan, east of Mount Bazard ̈z ̈ (the highest summit in Azerbaijan, Fig. 1), we lose the trace of the MCT and fieldwork has shown that is relayed by a string of fault-related folds. The Greater and Lesser Caucasus are seismically active zones linked to the rapid and non-uniform plate convergence between Arabia and Eurasia (Philip et al. 1989; Jackson 1992; Priestley et al. 1994; Triep et al. 1995; Jackson et al. 2002; Allen et al. 2004, 2006) (Fig. 1). The Lesser Caucasus and the adjoining Anatolian Plateau show a predo- minance of strike–slip focal mechanisms associated with a system of vertical faults. In the Greater Caucasus, on the contrary, convergence is accommodated predominantly by reverse focal mechanisms associated to thrusting with a general north–south to NE–SW compression (Ko ̧yigit et al. 2001; Barazangi et al. 2006; Copley & Jackson 2006; Tan & Taymaz 2006), see also discussion in (Jackson 1992; Allen et al. 2004). Slip vectors based on earthquake focal mechanisms show a general top-to-the-south thrusting. Strike – slip mechanisms exist but are rare. Present seismicity is unevenly distributed across the GC (Figs 1 & 3). A zone with a higher seismic activity is observed on the south slope of the Greater Caucasus west of Tbilisi (Georgia) in the Racha area (Triep et al. 1995). Studies of focal mechanisms and focal depths show that this seismicity is linked to several active fault strings in the subsurface of the Gagra-Dzhava zone (Triep et al. 1995; Gamkrelidze & Kuloshvili 1998). They show south directed slip vectors. These faults are located to the south and are structurally in the footwall of the MCT. To the west this fault system links to the MCT precisely where this latter shows an important bend, and is stepping back (to the north) into the mountain range (Figs 1 & 3a, b). We suggest that the MCT is developing a new splay, and that the higher seismicity in this region is due this propagation of the MCT to the SW and to a lower structural level (Fig. 3a). To the east this fault system may be correlated with the thrust fault at the front of the Alasani Basin. It is relevant to notice that elsewhere in the Greater Caucasus the largest earthquakes known (earthquakes . magnitude 6, both historical and measured) are all located in the vicinity of the MCT. We interpret this to show the importance of the MCT to the present day in the deformation processes, since large earthquakes occur along large faults accommodating important displacement. The MCT appears to be a major thrust in the development of the Greater Caucasus. Seismicity is extending into the Middle and South Caspian Sea (Kovachev et al. 2006). In the Apsheron zone focal mechanisms show NNE– SSW oriented thrusting (Jackson et al. 2002) and seismic activity may be linked with an extension / termination of the Greater Caucasus towards the East and / or with young north-directed subduction of the South Caspian Basin to the North under the Apsheron (Allen et al. 2002; Knapp et al. 2004). The seismicity further south as well as in the Gobustan desert area shows a westward component of motion relative to Eurasia, suggesting underthrusting towards the west (Jackson et al. 2002). Some seismic activity is also seen in the central part of the eastern Greater Caucasus, as well as in the Kura basin. On the northern slopes, the Dagestan FTB and the recent faults in the Terek Basin show a higher concentration of earthquakes pointing to active thrust tectonics in this area. Studies on palaeoseismology remain rare but confirm the existence of inherited faults and the possible 2000 year recurrence of high magnitude events (Rogozin et al. 2002; Rogozin & Ovsyuchenko 2005). Studies based on GPS technologies in the larger Caucasus area, including Turkey, Arabia and Iran have confirmed the global picture of convergence across the Caucasus (McClusky et al. 2000; Nilforoushan et al. 2003; Reilinger et al. 2006). The average convergence of Arabia and Eurasia of 18 –23 mm a 2 1 is transformed into a deformation of 14 mm a 2 1 with a north–south direction across the Greater Caucasus, mainly the southern part (Vernant et al. 2004). Detailed studies in Azerbaijan (Kadirov et al. 2008) confirm a rotational convergence between Arabian and European plates. Shortening is distributed between the Northern Kura Basin and the outermost thrusts of the Dagestan FTB. Present-day slip rates decrease from 10 + 1 mm a 2 1 in eastern Azerbaijan to 4 + 1 mm a 2 1 in western Azerbaijan (Kadirov et al. 2008). A similar study in Georgia shows the opposite thrust directions between south-dipping thrusts in the Adjara-Trialet FTB and the Greater Caucasus front, which shows relative motion of 6.9 + 1.1 mm a 2 1 to the SW on north-dipping thrusts (Gamkrelidze & Kuloshvili 1998). These studies also show a marked change (decrease) in velocities across the MCT. Indeed north of the MCT velocities are almost 0, indicating no longi- tudinal displacement. All deformation appears to be taken up in uplift. Across the more or less north –south oriented West Caspian Fault – at the transition Kura basin to Gobustan area near the eastern shores of the South Caspian Sea – a recent study indicates a dextral strike –slip motion and calculates a differen- tial movement of 11 + 1 mm a 2 1 (Kadirov et al. 2008). The Greater Caucasus basin was initiated by Mesozoic back-arc extension related to the subduction of the Tethys Ocean to the ...

Context 11

... 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 range with 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 Kura- Kartli 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 component of convergence and a complex plate boundary with vertical and horizontal strain partitioning (Jackson 1992). Recent convergence rates of up to 14 mm a 2 1 , strong earthquakes, landslides, active volcanoes, and extreme subsidence and surface uplift rates are indicative for the dynamics of the continent– continent collision. From east to west, the morphological shape and the structural features are strongly influenced by the rotational convergence of the Arabian plate and westward escape of the Anatolian Plate causing distinct tectonic regimes in the Caucasus. The Lesser Caucasus area is dominated at present by a strike–slip regime, whereas the Greater Caucasus is dominated by thrust tectonics with a main NNE –SSW direction of movement. The dominant movement is top to the south in the main range and the southern slopes. Top-to-the-north motion is observed in the areas in the north and in Dagestan. Hereafter we will present different aspects of Cenozoic and recent tectonics, and tectonic geomorphology, especially based on detailed structural studies carried out over several years in the eastern Greater Caucasus in Azerbaijan. We shall discuss their relevance for understanding the thrust kinematics and the links between tectonics, topography, seismicity and uplift in the Greater Caucasus. The geodynamics of the Greater Caucasus orogen correspond to an intercontinental collision zone inverting a deep Mesozoic –Cenozoic basin (Fig. 2) that is not located above a subduction regime, but bordered east and west by super deep sedimentary basins that have their origin in the Mesozoic and are filled with Cenozoic– Quaternary sediments. To the north and south of the Greater Caucasus are the foreland basins of the Terek-Kuban and the Kura-Kakheti-Kartli-Rioni, respectively (Ershov et al. 1999; Mikhailov et al. 1999; Ulminshek 2001; Daukeev et al. 2002; Ershov et al. 2003); to the east and west are the Caspian Sea and the Black Sea, respectively (Shikalibeily & Grigoriants 1980; Berberian 1983; Ismail-Zade et al. 1987; Narimanov 1992; Abrams & Narimanov 1997; Mangino & Priestley 1998; Nikishin et al. 1998; Allen et al. 2002; Brunet et al. 2003; Nikishin et al. 2003). The Lesser Caucasus is situated above an old, possibly detached subduction slab (Hafkenscheid et al. 2006). An incipient subduction is believed to have occurred at the northern edges of the Black Sea, whereas in the east the subduction process was already initiated in Pliocene times, when the South Caspian Basin started subducting to the north under the eastern termination of the GC and the Apsheron Ridge (Allen et al. 2002; Knapp et al. 2004). The detailed link of the incipient subduction to the structures such as the Main Caucasus Thrust (MCT) in the Greater Caucasus remains to be investigated. The depth of the Moho changes from about 40 km beneath the Kura basin to more than 50 km beneath the eastern Greater Caucasus and rises to 40 km again under the northern foreland basin (Brunet et al. 2003; Ershov et al. 2003). The Greater Caucasus is a doubly verging mountain-belt (Fig. 2) with two external fold-and- thrust belts (FTB) and a complex nascent axial zone (Sholpo 1993; Khain ...

Context 12

... 2. General crustal-scale cross-section through the eastern Greater Caucasus and the Lesser Caucasus (location see Fig. 1). The Lesser Caucasus is associated with a northward subduction and possibly a detached slab [based on tomography after Hafkenscheid et al. (2006)]. No subduction is seen under the Greater Caucasus. The Greater Caucasus is a doubly verging orogenic wedge with the dominant thrusting towards the pro-wedge to the South. A retro-foreland fold-and-thrust belt develops to the north in Dagestan (Russia) see also Figure 1. Three different types of crust have been distinguished according to their geodynamic belonging: to the South a crust intruded and associated with the Jurassic– Cretaceous suprasubduction arc volcanism in the Lesser Caucasus, in the centre the thinned and rifted and intruded southern part of the supra-subduction backarc basin, and to the north the northern part of this extended backarc rift system with the important Mesozoic sedimentary series of the Greater Caucasus Basin. Some major faults such as the Main Caucasus Thrust (MCT) are highlighted. The structure and the position of the thrusts at depth remains speculative, but indicate underthrusting of the terranes to the south of the Greater Caucasus and strong imbrication over a ramp system in the Greater Caucasus.  ...

Context 13

... 2. General crustal-scale cross-section through the eastern Greater Caucasus and the Lesser Caucasus (location see Fig. 1). The Lesser Caucasus is associated with a northward subduction and possibly a detached slab [based on tomography after Hafkenscheid et al. (2006)]. No subduction is seen under the Greater Caucasus. The Greater Caucasus is a doubly verging orogenic wedge with the dominant thrusting towards the pro-wedge to the South. A retro-foreland fold-and-thrust belt develops to the north in Dagestan (Russia) see also Figure 1. Three different types of crust have been distinguished according to their geodynamic belonging: to the South a crust intruded and associated with the Jurassic– Cretaceous suprasubduction arc volcanism in the Lesser Caucasus, in the centre the thinned and rifted and intruded southern part of the supra-subduction backarc basin, and to the north the northern part of this extended backarc rift system with the important Mesozoic sedimentary series of the Greater Caucasus Basin. Some major faults such as the Main Caucasus Thrust (MCT) are highlighted. The structure and the position of the thrusts at depth remains speculative, but indicate underthrusting of the terranes to the south of the Greater Caucasus and strong imbrication over a ramp system in the Greater Caucasus.  ...