Recent geodynamics, active faults and earthquake focal mechanisms of the zone of pseudosubduction interaction between the Northern and Southern Caucasus microplates in the southern slope of the Greater Caucasus (Azerbaijan)

Our study was focused on the active tectonics of the southern slope of the Greater Caucasus within Azerbaijan. The study area is the zone of under-thrusting (pseudosubduction) interaction between Southern and Northern Caucasus continental microplates, which caused the tectonic stratification of the Alpine formations into various allochthonous and parauthochthonous thrust slices of southern vergency between the Middle Bajocian and Quaternary periods. These slices are grouped into the nappe complexes that form the modern structure of the trough in the study area. The large linearly stretched tectonic units (megazones) correspond to the axis of the Alpine marginal sea basin, the consolidated crust of which is subjected to destruction and thinning. The trough’s Alpine cover was compressed in the underthrust zone and pushed southwards. As a result, an accretionary prism formed allochthonously overlapping the northern side of the Southern Caucasus microplate by the system of gently dipping overthrusts. During the continental stage of Alpine tectogenesis (starting from the end of Miocene), intensive lateral compression process was caused by intrusion of the frontal wedge of the Arabian indenter into the buffer structures of the southern frame of Eurasia. This is evidenced by the GPS monitoring data on modern geodynamic activity, which demonstrates the Southern Caucasus block’s intensive (up to 29 mm/year) intrusion in the northern rhumbs as compared to the relative stability of the Northern Caucasus microplate (0–6 mm/year). This, in turn, is a reflection of the ongoing pseudosubduction regime (continental subduction or S-subduction) at the band of collision junction of these microplates. It is suggested that this process caused historically observed seismic activity in the study area, wherein the earthquakes occurred mainly in the southern slope’s accretionary prism area and the adjacent strip of the Southern Caucasus microplate. In this article, we analyze and correlate the whole range of seismic events that occurred in the study area until 2017 and the focal mechanisms of the recently recorded earthquakes (2012–2016). It is established that earthquake foci are confined either to the intersection nodes of variously trending ruptures with the faults of different directions or to the planes of deep tectonic ruptures and lateral displacements along the unstable contacts between the material complexes with different competence. The focal mechanisms of seismic events reveal various, mostly near-vertical, planes of normal and strike-slip faults. However, the earthquake foci are generally confined to the intersection nodes between the Caucasus and anti-Caucasus-striking rupture dislocations. The results of our studies are interesting in terms of their real-time application for drawing a regional summary of causes for both geodynamic and seismic activity of the Greater Caucasus system and the adjacent areas of Alpine-Himalayan fold belt.


INTRODUCTION
According to established ideas [Khain, 1984[Khain, , 2001Akhmedbeyli et al., 2002;Khain, Alizadeh, 2005;Kangarli, 2012], the present tectonic setting of the Caucasus has formed during the Alpine stage of tectogenesis within the south side of the Eurasian continent, the Lesser Caucasus offset Meso-Tethys and the northern side of the Central Iranian microcontinent (Fig. 1). It's widely believed that compression of the Caucasus neck's territory in a collisional zone of mentioned lithosphere plates determines its' modern geodynamics and seismic activity. Wherein, the southern slope of the Greater Caucasus system remains one of the most seismically active areas with periodically occurring large seismic events accompanied by spontaneous largescale energy release. The area's seismic activity is connected with an ongoing intensive structural plan reconstruction with considerable amplitudes of latest and modern movements. Earthquake focuses are normally confined to boundaries of the earth crust's large geotectonic elements and to the intersections of differently striking faults. Seismological and paleoseismotectonic studies as well as seismic and seismotectonic zonation activities carried out in different seismic regions of the Caucasus (including the territory of Azerbaijan), all stand for the assumption that a core zone of the earthquakes is controlled by a network of "general-Caucasus" and "anti-Caucasus" striking faults with different types of displacements. However, modern seismic activity is generally caused by the horizontal movements of the different-scale tectonic blocks compressed in a collisional interaction zone between Afro-Arabian and Eurasian continental plates 1 .
1 Presently, a group of researchers (E.A. Rogozhin, A.V. Gorbatikov, V.B. Zaalishvili, M.Yu. Stepanova, N.V. Andreeva, Yu.V. Kharazova, A.N. Ovsyuchenko and others ) on the basis of the results of the application of microseismic sounding method in combination with other geological and geophysical methods, the essential role of internal causes in the processes of orogenesis and folding in the Greater Caucasus without taking into account the processes of lateral compression under the influence of lithosphere plates motion is defended. Such interpretation is based on the position of the now departed V.V. Belousov on the generation of internal deformations and orogenesis under the influence of the processes of differentiation of matter in the earth interior and advective movements in the upper layers of the lithosphere. However, a large amount of geological and geophysical information (at least, for the whole territory of Azerbaijan and the Caspian Sea, seismic exploration data from MOGT (Fig. 9) and recent GPS data (Fig. 15) clearly defend) allow one to defend the plate-tectonic nature of the formation of the Greater Caucasus, and the entire Alpine-Himalayan folded belt.

METHODS
Geological-tectonic structure of the Azerbaijani part of Greater Caucasus was studied using the well-known geological mapping methods of complexly built nappethrust structures in combination with deep geological mapping through geophysical methods (CMRW -Correlation Method of Refracted Wave, RWM -Reflected Waves Method, MSDP -Method of Separate Deep Point, MEEW -Method of Earthquake Exchange Wave, MTS -Magneto-Telluric Sounding, DS -Dipole Sounding and transformation of the geophysical fields), and the deep well and remote sensing data. This allowed us to precisely describe the structure and composition of the Alpine complex, characterize behavior of the pre-Jurassic basement's surface, and trace correlation between structural elements from different levels of the earth crust [Kangarli, Akhundov, 1988;Khain, Alizadeh, 2005;Kangarli, 2012].
Horizontal present day crustal motion velocities were determined according to records of the stationary GPS surveying network through using the software package of GAMIT-GLOBK. Velocities were assessed within the framework of global reference frame, supported by the International Reference Frame (ITRF) as applied to the Eurasian plate.
In recent years, it became possible to build focal mechanisms by using specially developed software. In this paper, we used the outcomes of earthquake focal mechanism calculations, registered by a network of digital seismic stations. These focal mechanisms were calculated at the Republican Centre of Seismological Survey, using «FPIT» Software developed by "Kinemetrics". This software used the signs of initial P-wave arrivals to the digital stations located within the epicenter distance interval of 15-350 km with fairly even azimuthal distribution [Rzayev et al., 2013;Yetirmishli et al., 2016].

RESULTS
Critical analysis of the space-time distribution of violent earthquake focuses during the instrumental monitoring period in Azerbaijan leads to a conclusion that the hypocenters have concentrated mainly within the exocontact parts of the seismotectonic zone of the Southern slope of Greater Caucasus. Being a part of the Alpine-Himalayan fold belt, the zone had formed during the Alpine stage of tectogenesis under the geodynamic environment of lateral compression peculiar to the area of pseudo-subduction interaction between the Northern and Southern Caucasus continental microplates. Its' present structure was formed as a result of the horizontal movements of different phases and subphases of the Alpine tectogenesis (Late Cimmerian -Wallachian), and is generally regarded as a zone where, along Zangi (Kbaad-Zangi) dislocation (to eastern part of Krasnopolyansk thrust in North-East Caucasus), the insular arc formations of the northern edge of Southern Caucasus microplate have underthrusted beneath the Meso-Cenozoic substantial complex contained in the facies of Greater Caucasus marginal sea [Dotduev, 1986[Dotduev, , 1989Baranov et al., 1990;Kangarli, 1999Kangarli, , 2005Kangarli, , 2012Khain, Alizadeh, 2005;Kangarli et al., 2018]. The latter was in turn thrusted under the Northern Caucasus continental margin of the Scythian-Turanian plate (epi-Hercynian platform) along the Major Caucasus fault, forming an accretionary prism jammed between the aforesaid dislocations (Fig. 2).
Outcomes of geology-geophysical investigations of the territory of Azerbaijan and its' Caspian Sea sector, conducted in the last quarter of the past -the beginning of this century [Kangarli et al., 1994Kangarli, 1999Kangarli, , 2012Khain et al., 2007;Mamedov, 2008Mamedov, , 2010; say for a pseudosubduction (C-subduction) interaction between the Southern and the Northern Caucasus microplates, resulting in tectonic stratification of the Alpine formations of continental slope, marginal sea and insular arc into different south-vergent scale plates combined into the nappe complexes (Fig. 3, 4).
Thus, the Northern Caucasus edge of the Scythian-Turanian plate (Daryal-Shahnabad-Jimi complex of the Side range of Greater Caucasus) presents itself as an allochthonous cover, while the Alpine complex of the northern side of Southern Caucasus microplate appears as an autochthonous (parautochthonous) basement of the accretionary prism. Autochthonous bedding of the Southern slope's accretionary prism is represented by a Meso-Cenozoic complex of the northern Kakheti-Vandam-Gobustan margin (megazone) the Southern Caucasus microplate. Mentioned complex is in turn crushed and lensed into the southward shifted tectonic slices which gently overlap the northern flank of Kur depression along Ganikh-Ayrichay-Alat overthrust.
The autochthonous complex, northern wing of which is buried beneath the accretionary prism, consists of complexly interrelated Mesozoic-Cenozoic sedimentary and volcanic formations. In surface structure the complex is represented by two structural zones: Kakheti-Vandam zone in the west, and Shamakhy-Gobustan zone in the east [Khain, Alizadeh, 2005].
First zone corresponds to a marginal uplift of the Southern Caucasus microplate -contemporaneous with the Gagra-Java zone of Georgia. Within the boundaries of Azerbaijan, revealed are the fold-complicated crest and near-crest part of the northern limb of the uplift built by Middle Jurassic volcano sedimentary to Paleogene terrigenous formations. In its' remaining parts in the west, the uplift gets leveled by Eopleistocene-Quarternary continental molasse of Ganikh (Ala-zani)-Ayrichay superimposed depression, while in the east it buries under the Shamakhy-Gobustan zone's Paleogene deposits. Further in the west (Kakheti, Eastern Georgia), parautochthone pack of tectonic slices protrudes in front of the accretionary prism ( Fig. 11) formed by Middle Jurassic-Eocene deposits in the "vandam" facies [Gamkrelidze P.D., Gamkrelidze I.P., 1977].
Shamakhy-Gobustan zone is revealed on the eastern plunge of Kakheti-Vandam Mesozoic complex and mainly composed of Paleogene-Neogene clayey formations. It is characterized by complex fold-nappe structure and represented on surface by three packs of the differently rooted thrust sheets [Khain, Alizadeh, 2005;Kangarli, 2005Kangarli, , 2012. Parautochthonous slices of the northern strip are represented by homologues of the Kakhetian parautochthonous pack of tectonic sheets protruding in front of Govdagh-Sumgayit nappe complex of the accretionary prism (see Fig. 4).
The fault tectonics, that constructs a structural plan of the region, like for the entire Caucasus, is extremely complex. According to the morphology and type of displacements, fault dislocations are divided into: 1 -deep faults at the boundaries of structural megazones; 2 -faults at the boundaries of structural zones and subzones; 3 -longitudinal thrusts, upthrust-overthusts, thrusts, (in some cases with a strike-slip component), complicating the internal structure of structural zones as branches of disjunctive dislocations of the first and second order; 4 -transverse and diagonal flexures, normal faults and strike slip faults, rarely thrust-strikeslip faults, controlling the transverse block divisibility of the Earth's crust.

Faults at the boundaries of structural zones
and subzones represent large disjunctive dislocations, often penetrating into the pre-Jurassic basement and expressed by upthrust-overthrust and upthrust type zones having south vergency. Within the study area, they include Khuray-Malkamud, Gamarvan, Dashaghil-Mudrisa and Shambul-Ismayilly dislocations.
3. Longitudinal ruptures that complicate the internal structure of structural zones and subzones are presented by elementary upthrusts at the base of the tectonic wedge scales of the accretionary prism, and also complicate the structure of folded dislocations of various orders in a form of axial and wing upthrusts, upthrustes-overthrusts, rarely strike-slip and normal faults.
4. Disjunctive dislocations of the "anti-Caucasian" direction reflect the transverse and diagonal zoning of the study area. They are also well expressed in geophysical anomalies at considerable depths, probably controlling the divisibility of the crystalline basement at deeper levels than longitudinal dislocations. Forms of manifestation and the direction of the "anti-Caucasian" disjunctives differ with huge variety and complexity. These are usually ruptures of normal, rarely upthrust nature faulting type with a right-, less often, left-lateral component. In separate, each rupture usually has a short length, but enters a long-length echelonlike row. Single discontinuities of considerable length are also observed.
Disjunctives of the north-eastern stretch have clearly expressed displacement planes or are closely spaced fracture zones, often accompanied by ruptured microfolding, narrow crushing and limonization zones, veins of calcite.

Characteristics of nappe complexes of the accretionary prism of the Greater Caucasus
Характеристики покровных комплексов аккреционной призмы Большого Кавказа arrangement and closure of individual folds and allochthonous scales in the geological structure, as well as flexure curves in the general strike of folding and are represented by extended right shifts or their zones intersecting diagonally study area. The largest of zones of right-lateral dislocations one of the northwest strike in the South-Eastern Caucasus is the West-Caspian fault zone with 35-40 km wide, which is clearly mapped by a complex of geological and geophysical methods [Khain et al., 1966;Kangarli, Akhundov, 1988] and continues within East-Dagestan diagonal flexures zone. Near longitudinal discontinuous dislocations occupy an intermediate position between NE and NW disjunctives and are usually represented by right-lateral strike-slip faults of significant amplitude.
Continental stage of tectogenesis is directly related to injection of the frontal wedge of Afro-Arabian indenter to the south and, as a consequence, reanimation of the lateral compression process in the pseudosubduction interaction zone of Southern and Northern Caucasus microplates at the territory of Caucasus neck. This process is accompanied by secondary stretching efforts occurred on the intender's eastern and western flanges, generating strike-slip dislocations with an anti-Caucasian orientation. Such orogeny formation mechanism is proposed by different researchers for the Greater Caucasus and the entire Caspian-Caucasus-Black Sea region [Aliyev, 2014;Allen et al., 2004;Philip et al., 1989, Kopp, 1997Khain, 2001;Akhmedbeyli et al., 2002;Jackson et al., 2002;Khain, Chekhovich, 2006;Vincent et al., 2007;Kangarli, 2012;Kadirov et al., 2015;Aliyev et al., 2018]. Namely, the process of С-subduction defines geological-tectonic and geodynamic background for the southern slope's seismic activity within and outside of the Azerbaijan's territory.
vertical and subhorizontal contacts in the earth crust from another [Kangarli, Veliev, 1988;Kangarli et al., 2016Kangarli et al., , 2017aTelesca et al., 2017;Aliyev et al., 2018]. Horizontal and vertical seismic zonality can be explainned from the viewpoint of block divisibility and tectonic stratification of the earth crust. Within the crust's structure, earthquake focuses are confined mainly to the intersection knots between differently oriented rupture dislocations, or to the planes of deep tectonic failures lateral displacements along the unstable contacts between the material complexes with different competency [Kangarli, Veliev, 1988;Alizadeh et al., 2013;Kangarli et al., 2016Kangarli et al., , 2017aKangarli et al., , 2017bAliyev et al., 2018].
Based on the space-time focus distribution analysis of all M≥3 earthquakes recorded through a period of instrumental observations (1902-2017), we traced the seismic activity dynamics within the southern slope zone's frontiers (Fig. 12, 13) and came to the following conclusions: 1. Using the outcomes of geophysical data reinterpretation and the region's resultative tectono-magmatic scheme [Kangarli, Akhundov, 1988;Kangarli, 2012], following 4 blocks separated by the anti-Caucasus striking fault zones may be distinguished in the west-to-east direction, all with different characteristics of seismic activity: Zagatala, Shaki, Gabala-Shamakhy and Gobustan. First two blocks belong to the eastern, and the other two to the southeastern segments of Greater Caucasus system (see Fig. 12). The boundary between these two segments is determined by Samur-Aghdash leftlateral strike-slip fault. Herewith, the vertical seismic focus distribution indicates a regular distribution of most earthquake hypocenters within 12-30 km depths of the pre-Jurassic basement (Fig. 13, 14).
2. First two blocks are distinguished for their lower seismic activity recorded throughout the entire period of observations (see Fig. 13): -until 1980, 12 seismic events occurred within the Zagatala block's frontiers, confined to the consolidated crust's upper segment. Absolute majority of focuses (11) is located at depths of 12-30 km. Since 1980 until present, 66 events were recorded, with 9 events sourcing from the sedimentary cover, and 57 -from 5-30 km depths of the consolidated crust; -14 seismic events have occurred in Shaki block until 1980, 3 of which were confined to 3-5 km deep parts of the alpine cover, and the rest were located in the consolidated crust's upper segment (5-30 km). In 1981-2017, the number of events increased to 65, 3 of which took place in the sedimentary cover, 61 -in the consolidated crust (58 in the upper and 3 in the lower segment), and 1 -below the Moho discontinuity.
3. Gabala-Shamakhy and Gobustan blocks have been more active throughout the entire period of observations, but there were also the leaps of seismic activity recorded in last quarter of XX century: -until 1980, the total 29 seismic events have been registered within the block's structure, including the Alpine cover (14) and the consolidated crust's upper segment (14 events at depths of 5-30 km, and 1 event below the Moho disgontinuity). In the following period, the block's seismic activity increased to 219 events, 46 of which occurred in the sedimentary cover, 171 -in the consolidated crust (141 -5-30 km, 30 -31-45 km), and 8 -below the Moho discontinuity; -23 seismic events have occurred in Gobustan block until 1980. 8 events were confined to the Alpine cover, 11 -to the upper (5-30 km), and 4 -to the lower segment (31-45 km) of the consolidated crust. During 1981-2017, the number of events increased to 196, 30 of which occurred in the sedimentary cover, 187 -in the consolidated crust (139 in the upper and 48 in the lower segment), and 9 -below the Moho discontinuity.
4. Even with allowances made to potential errors of earthquake registration technology and methods of the first half of XX century, it has to be stated that the certain rise in the area's seismic activity is generally observed since 1980 (see Fig. 14). Within the zone's eastern segment, active is the upper part of the consolidated crust. In the southeastern segment, seismic activity affects an entire earth crust and even the uppermost part of the mantle. Majority of deep seismic focuses is located in the zone of submeridional Western Caspian fault (north-west oriented right lateral dislocations in Eastern Caspian zone), to the east of which observed is a stepped dipping of the consolidated crust towards the Caspian hollow. Рис. 13. Гистограмма вертикального распределения очагов землетрясений с М≥3 в блоках земной коры южного склона Большого Кавказа в Азербайджане (1902-2017 гг.). Составитель: Ф.А. Алиев.

5.
Observed seismic activity is generally consistent with data on lateral movement velocities produced since 1998 by GPS monitoring of the region's modern geodynamics [Kadirov et al., 2008[Kadirov et al., , 2009[Kadirov et al., , 2015[Kadirov et al., , 2018Kadirov, Safarov, 2013;Telesca et al., 2017]. By 2014, lateral movement velocities of the most monitoring stations have increased by 2-8 mm/year as compared to a baseline of 2004 (Fig. 15). Meanwhile, similar-to-seismic transverse zonality is observed in the velocity distribution: thus, the velocities average at 8-10 mm/year to the west and exceed 13 mm/year (13-29 mm/year) to the east of Samur-Aghdash dislocation.
Simultaneously, a longitudinal zonality is observed in the distribution of horizontal movement velocities, which correlates with the territory's "general-Caucasus" tectonic zonality.
Described process continues also at a contemporary stage of alpine tectogenesis, as demonstrated by realtime GPS surveying of regional geodynamics. Analysis of data on the distribution of vectors of the lateral movement velocities (produced in 1998-2014 by GPS geodesic stations in Azerbaijan and adjacent territories of Iran) indicates considerable (up to 29 mm/year) velocity of the north-northwestward movement of the southwestern and central parts of the Southern Caucasus microplate, including territory of Lesser Caucasus southeastern segment, Kur depression and Mountainous Talish. At the same time, vectors reduce to 6-13 mm/year within the microplate's northeastern flange confined to Kakheti-Vandam-Gobustan megazone of Greater Caucasus, and become as low as 0-6 mm/year (data of 2010-2014) further in the north, on a hanging wall of Kbaad-Zangi deep underthrust, i.e. directly within the accretionary prism's boundaries. In general, the belt's earth crust shortening rate is estimated as 4-10 mm/year. The aforesaid is confirmed by the earth surface movement directions and velocities registered in Azer- Рис. 14. Гистограмма, показывающая пространственные (по глубине) и временные изменения сейсмической активности (землетрясения с М≥3) в Азербайджанской части южного склона Большого Кавказа за период 1902-2017 гг. Составитель: Ф.А. Алиев.
baijan and its' adjacent territories based on the outcomes of GPS observations implemented in 2015 (Fig.  16). Velocity field clearly demonstrates the north-northeastward motion of the earth surface. One feature of the velocity field is clearly demonstrated by the developed diagrams. It consists in a contrasted decrease   [Kadirov et al., 2015.
This phenomenon reflects gradual accumulation of the elastic lateral compression deformations within the zone of pseudosubduction interaction between structures of the northern side of Southern Caucasus microplate (Kakheti-Vandam-Gobustan megazone) from one side and the accretionary prism of Greater Caucasus from another.
Real time effects of the tangential stresses are also indicated by focal mechanisms of M≥3 earthquakes occurred in the region for the period of 2003. Distribution analysis of the compression and extension axes speaks for predominance of lateral compression oriented in submeridional and NE-SW directions.
Types of focal mechanisms of the southern slope zone of Greater Caucasus generally correspond to a notion of geodynamics of the microplates' convergent borders [Rzayev et al., 2013;Alizadeh et al, 2013;Yetirmishli et al, 2014Yetirmishli et al, , 2016Kangarli et al., 2016Kangarli et al., , 2017aKangarli et al., , 2017bAliyev et al., 2018], where the entire range of focal mechanisms, from normal-fault to thrust faulting is observed (Fig. 18).
Space-time distribution analysis of the strong earthquake focuses in the Azerbaijani part of Greater Caucasus region leads to a conclusion that at present stage of tectogenesis most seismically active are structures on the northern flank of Southern Caucasus microplate (both the structures that are buried under the accre-tionary prism in the north, and the structures that get revealed in a central segment or get covered by a quaternary cover on the southern part of Kakheti-Vandam-Gobustan zone), located in the following two areas: -zone controlled by a "general-Caucasus" striking Ganikh-Ayrichay-Alat deep overthrust (corresponds to a border of Kakheti-Vandam-Gobustan and Middle Kur tectonic megazones), in the west of the Azerbaijani part of the Greater Caucasus; -complex tectonic node located in the east of described region within the boundaries of Talish-Samur-Makhachkala submeridional seismotectonic zone: corresponding to an intersection of two faulting zones: 1) northwest striking Western Caspian zone bordered by Pirsaat and Sighirly elementary deep strike slips from the northeast and southwest), and 2) northeast striking Girdimanchay-Shamakhy zone represented by Basgal-Khashi, Aghsu-Khaltan and Jalair-Dibrar dislocations.
Under lateral compression environment, small-scale blocks that constitute the region's earth crust trigger the emergence of transpressive deformations, which combine the shear displacements along framing transverse deformations with the compression structures like "general-Caucasus" ruptures. Such regime leads to an emergence of multiple concentration areas of the elastic deformations confined to the mentioned dislocations and their articulation knots. It is just the exceeded ultimate strength of the rocks that causes an energy discharge and brittle destructions (according to stick-slip mechanism) in such tectonically weakened regions of the southern slope of the Azerbaijani part of Greater Caucasus (see Fig. 12).
The aforesaid is particularly evidenced by the following seismic events that occurred in the Northwestern part of Azerbaijan during 2012-2016 (Fig. 19, 20). , and confined to a plane of Ganikh-Ayrichay-Alat thrust fault that gently plunges in the northern rhumbs at its' intersection with northeast striking Zagatala transtensional fault. In general, the focal zone represents a complex disjunctive knot inside the pre-Jurassic basement's upper segment, consisting of the elementary intersections of differently striking tectonic deformations to which the earthquake hypocenters are confined (see Fig. 12, 19). Approximate volume of a rock mass to which the hypocenters of all М≥3 events are confined, reaches 3400 km 3 . Seismic events were mainly related with Zagatala transverse fault's activation which have caused an intensification of connected "general-Caucasus" and "anti-Caucasus" deformations. Earthquake mechanisms can help indi-cate fault slip along active fault zones. An example of this would be the May 7, 2012 earthquake that had a large number of aftershocks (Fig. 21, I and II). First shock (М=5.61, Н=9 km) was characterized by near-lateral (PL P =10°) compressive and stretching (PL Т =14°) stresses. The type of movement along both steep (DP 1 =87°, DP 2 =72°) planes is a dextral shift. NP1 plane has northeastern (STK 1 =125°), and NP2 plain has southwestern (STK 2 =216°) strike. Comparing nodal plane strikes with fault lines demonstrates their compliance with the Shambul-Ismayilly fault (rear scale of Ganikh-Ayrichay-Alat thrust fault) of a "general-Caucasus" strike (NP1) and the Zagatala fault with an "anti-Caucasus" strike (NP1). Second shock (М=5.7, Н=12 km) occurred due to an impact of near-lateral stretching stresses (PL Т =1°). Type of movement along both relatively gentle (DP 1 =48°, DP 2 =50°) planes is downthrow. NP1 has southeastern (STK 1 =130°), and NP2 has northwestern (STK 2 =340°) strikes. The strike of the nodal planes is correlated with that of the Shambul-Ismayilly "general-Caucasus" (NP1) and Bulanigchay-Verkhiyan "anti-Caucasus" (NP2) tectonic deformations. Data analysis allows considering the NP1 plane as the event's major acting component. Mechanisms of the majority of aftershocks points at strike-slip movements within the focal zone's structure with subordinate amount (5 events) of upthrust displacements confined to a plane of Ganikh-Ayrichay-Alat thrust fault and its' rear scales.
Balakan focal zone was active in 2012, 2013 and 2016. Seismic events of October-November, 2012, manifested themselves through a series of earthquakes with a maximum Mw of 5. 60 (14.10.2012). Events of the following years were characterized by relatively low magnitudes of 3.1-4.4. Like in the previous case, the focal zone is confined to a complex intersection of differently striking tectonic deformations with earthquake hypocenters (depth interval of 4-13 km) is located at pre-Jurassic basement, as well confined to surface of the basement and bottom of the Alpine cover of Kakheti-Vandam-Gobustan zone (Fig. 20, section II-II'). Approximate volume of a rock mass to which the hypocenters of all М ≥ 3 events are confined, reaches 500 km 3 . Seismic events are mainly related with activation of Khimrikh-Khalatala (2012) and Balakan (2013 and 2016) faults with an "anti-Caucasus" strike. Seismic energy discharge occurred in the most crumble zones which correspond to the intersections of these deformations between each other and with "general-Caucasus" faults. Earthquake mechanisms in the focal zone point at a prevalence of downthrow and fault dislocations with subordinate role of the upthrust type shifts. In particular, October 14, 2012 earthquake (see Fig. 17) with M=5.6 and H=8 km was characterized by the lateral (PL P =0°) southwest trending stretching and the near-vertical northwest trending compressive (PL Т =48°) stresses (Fig. 21, III). Type of movement along both (DP=57°) planes is a fault. NP1 plane has a southeastern (STK 1 =115°) and NP2 plane has a northern strike (STK 2 =2°). Comparing nodal plane strikes with fault lines speaks for a compliance of NP1 with Shambul-Ismayilly latitudinal fault, and NP2with Khimrikh-Khalatala diagonal deformation.
zone within the depth interval of 5-9 km (see Fig. 20, section III-III'). The focal zone is confined to Gokhmug-Salyakhan northeast striking transverse deformation. Seismic energy discharge occurred alternately in the latter's intersection northwest striking rupture dislocations. Earthquake mechanisms of the studied period point at a prevalence of faulting dislocations. Example to this would be the May 14, 2012 earthquake (M=4.1, H=6) which was characterized by sublateral stretching (PL P =7°) stresses with southeastern orientation, as well as compressive (PL Т =14°) stresses with southwestern orientation (Fig. 21, IV). Movement type along both steep (DP=85-74°) planes is a fault. NP1 plane has northwestern (STK 1 =342°), and NP2 has northeastern (STK 2 =251°) strike. Comparing nodal plane strikes with fault lines (mapped through geology-geophysical methods) speaks for their compliance with Shin (NP1) and Gokhmug-Salyakhan (NP2) "anti-Caucasus" rupture dislocations. As indicated by the analysis and comparison of the geology-geophysical material, described seismic event is confined to a complex triple intersection of the "general-Caucasus" Shambul-Ismayilly and the "anti-Caucasus" Shin and Gokhmug-Salyakhan ruptures along the tectonically complicated exocontact of Shaki intrusive massif.
Gabala focal zone became active in Septemberbeginning of October, 2014. The event consisted of two sensible shocks with M=5.0-5.5 followed by several weak aftershocks. The focus zone is controlled by Damiraparanchay northeast striking dextral slip that complicates a line of an underthrust conjunction between the Kakheti-Vandam-Gobustan zone and the accretionary prism of Greater Caucasus. The focal zone is characterized mainly by shear displacements along the rupture's plane, as exampled by 29.09.2014 earthquake (M=5.5) which occurred at a depth of 13 km within the Kakheti-Vandam-Gobustan zone's pre-Jurassic basement. Mainly near-vertical (PL P =48°) compressive stresses prevailed in the seismic focus, oriented in sublatitudinal and submeridional directions (Fig. 21, VI). Type of movement along both steep (DP 1 =64°, DP 2 =53°) planes is a fault. Sublatitudinal (STK 1 =265°) NP1 plain is associated with Dashaghyl-Mudrisa upthrow-thrust fault with the "general-Caucasus" strike. NP2 plane has the northeastern strike (STK 2 =17°) and directly corresponds to the Damiraparanchay deformation.
Oghuz focal zone was active through two moderate earthquakes in September (M=5.9) and October (M=4.0), 2015. It is confined to a complex intersection between Fiy northeast and Ujar-Saribash northwest striking cross faults from one side and Ganikh-Ayrichay-Alat "general-Caucasus" deformation on the southern border of Kakheti-Vandam-Gobustan zone from another. September 4 and 13 earthquakes were impacted by the almost equivalent stretching and compressive stresses occurred at a depth of 16 km in the upper part of pre-Jurassic basement (Fig. 21, VII and VIII). Compressive stresses were near-lateral (PL P = =0-7°) with northeastern orientation, whereas the horizontal stretching efforts (PL Т =0-2°) had west-northwestern trend. Type of movement along both subvertical displacement planes (DP 1 =86-90°, DP 2 =83-90°) is a fault with left-hand horizontal component. First nodal plane of NP1 strikes southeastwards (STK 1 =153°) and dips towards the southwest. NP2 has the northeastern orientation (STK 2 =33°) and dips towards the southeast. Comparing nodal plane strikes with the region's rupture tectonics speaks for their conformity with Ujar-Saribash (NP1) and Fiy (NP2) "anti-Caucasus" rupture dislocations.
Other seismic events of the described period were characterized by weak magnitudes of less than 4.5. Their focuses were mainly grouped in the upper part and surface of pre-Jurassic basement, and subordinately within the Alpine cover's structure.

CONCLUSIONS
In our study, we correlated the space-time swarm sequence of the different-magnitude seismic events in each seismofocal zone of the Northwestern Azerbaijan. The correlation results bring us to the following conclusions: -The spatial distribution of the epicenters demonstrates that most seismic events are confined to transverse (northwest, northeast and submeridional striking) disjunctive dislocations. However, the epicentral zones generally have the 'general-Caucasus' strike along and to the north of Ganikh-Ayrichay-Alat deep upthrust. Both transverse and longitudinal dislocations were mapped by the complex of seismic and electrical survey methods as the natural southern extension of the faulting and strike-slip disjunctive zones. The latter outcrop in the mountainous area where complexes of the accretionary zone and its parautochthone bedding come to the ground surface.
-The complication of these complexes by the mentioned anti-Caucasus dislocations speaks for quite a young age of the latter, suggesting that they formed or were activated minimum during the post-Rodanian stage of tectogenesis, which is one of the factors to determine today's activity of these dislocations.
-In separate groups, the focal mechanisms reveal different, mainly subvertical, planes of normal, strikeslip and diagonal-slip movements in the earthquake foci. Only in four cases strictly upthrust and upthrustthrust movements were established.
-The major hypocenters (М=4.5-5.7) as well as the absolute majority of the aftershocks are confined to the surface or up to 20 km deep parts of the pre-Jurassic basement; -A considerable part of the swarm sequence's hypocenters is confined to the sloping band that plunges in the northern rhumbs and gets identified with the zone of Ganikh-Ayrichay-Alat deep thrust fault and its rear slices (Shambul-Ismayilly etc.).
-The increased seismic activity in the described period (until 2017) is explained by the accumulation of lateral compression stresses and their further release in the underthrust of the Middle Kura depression and the Vandam tectonic zones along the Ganikh-Ayrichay-Alat thrust fault.
-The lateral compression first contributed to the emergence of transpressional shears along the displacement planes of different-strike transverse faults, and to the energy discharge in the most broken and weakened zones that correspond to the intersection nodes between these dislocations and those between the above-mentioned overthrust and the rear slices of its northern branch.