These data come mostly from my diploma work, in case you want to use data from these page please cite my work like this :
"Bochud, M., 2006. Tectonic evolution of the Eastern Greater Caucasus. Diploma Thesis, University of Fribourg, Fribourg, 92 pp."
Sedimentology and stratigraphy (based on Babaev and Abdulkasumzade (1997))
This part describes in detail the sedimentology and the paleoenvironments of the different lithological units of the Eastern Greater Caucasus from the Jurassic to the Quaternary. It is based on Babaev and Abdulkasumzade (1997), an article translated from Russian. The translated paper suffers multiple errors in spelling geological terms and names of localities. We tried to uniform all names. Its goal is to make this very important text understandable and readable to allow a quick identification of the outcrops during the fieldwork.
During the Mesozoic, the main role in today’s Eastern Greater Caucasus is played by normal marine sedimentary deposits of Jurassic and Cretaceous age. In the Lesser Caucasus and the Kura depression, deposits are mainly volcanogenic-sedimentary formations of the same stratigraphic interval.
Mesozoic - Triassic
Triassic deposits have a thickness up to 1000m. They cover a considerable part of the Naxcivan territory except in the Eastern Greater Caucasus.
This area was exposed during this period but was not far from a basin in regard of the Lesser Caucasus deposits (shallow marine deposits with massive oolitic limestones, dolomites, a fauna of bivalves, ammonites and gastropods). The Upper Triassic is absent in Azerbaijan.
This period corresponds to the collision of the Cimmerian block and the closure of the Paleotethys. The basin was probably the beginning of a back-arc rift. Basin deposit crop out in the Lesser Caucasus. Its formation was tied to the subduction of the Paleotethys and afterward the basin was uplifted during the Cimmerian collision.
Mesozoic - Jurassic
Jurassic deposits are widespread in the south-eastern part of the Greater Caucasus. They crop out in separate local suites. The main complex deposits of Jurassic are marine. Outcrops of Jurassic occupy a vast territory in the pre-axial parts of the major Caucasian ridge. The richness of Jurassic deposits in natural resources is a result of their content, their formation and the favorable geological conditions of the area. The good perspective of these deposits concerning oil and gas contents is due to the important thickness of sandy-silt rocks, the regional bituminization and a generally high content of organic matter. Availability of surface oil and gas seepage prove the importance of these deposits for the economical income.
Lower Jurassic
The Lower Jurassic deposits are exclusively marine, with water depths up to 4000m.
Sinemurian
The Sinemurian deposits crop out in the interfluve of the Mazimcay and Balakancay rivers (west of the Eastern Greater Caucasus). They compose a great part of the Katsdag suite. Lithologically they are represented by limestones with interbeds of siltstone and argillaceous shales. In the upper part they alternate with volcanogenic and effusive rocks (up to 2000m).
Pliensbachian
The Pliensbachian deposits are common in the base of the same rivers and correspond to the Balakanian suite. They are composed of black shale-argillaceous sequences (up to 1000m).
Toarcian
The Toarcian deposits are spread in the Tufan anticlinorium. A typical section crops out at the head of Mazimcay River. It is represented by sequences of limestones and argillaceous shales in the Gubakh suite (Gora Gubakh Mountain).
Middle Jurassic
The Middle Jurassic is represented by all stages in the Greater Caucasus and is divided in two domains. The southern domain is wider and crops out in the eastern part of the Tufan anticlinorium. The northern domain is considerably narrower and coincides with the axial zone of the Tengy-Besbarmaq anticlinorium.
Aalenian
The Aalenian deposits are widespread in the east and especially in the south-eastern parts of the Tufan tectonic zone. They are represented mainly by alternations of dark-grey and black argillaceous shales, clays, silts and sandstones with interbeds of carbonate rocks. They form the Qarxunian suite. A typical section is located at the head of Qarxun River (500m). The Aalenian deposits crop out in drillings in the buried structures of the south-east depression of the Greater Caucasus (areas of Baybayim Dagi-Tugcay River and Kescay River). Aalenian deposits contain commonly organic matter and have a detritic facies. In some area, they also include siderite nodules (centimeters scale) and cone-and-cone structures. Nodules are hard bodies of rock with a different composition than the sediments that contain them. Nodules may form by the selective precipitation of minerals that completely replace the original sediment, though some, such as siderite nodules, may form from a gel precipitated under reducing conditions. The cone-and-cone structure generally develops in organic rich mudrocks during burial, and may relate to calcite crystal growth under high pore-fluid pressure during compaction (Tucker, 2001).
Bajocian
Deposits of the Bajocian stage are widespread in units of the Tufan, Vandam, Tengy-Besbarmaq and Zaqatala-Qovdag tectonic zones. The Lower Bajocian deposits are lithologically identical to the Upper Aalenian ones. They form together the Jiminskaya suite where argillites and siltstones are dominant. Most typical sections of the Jiminskaya suite are located in the basins of Qaracay and Cimicay rivers (up to 450m). The Jiminskaya suite is overlain by the Xinaliq sandstones and is widespread in the east part of the Tufan tectonic zone.
Bathonian
The Bathonian deposits in the Eastern Greater Caucasus are not widespread and crop out only in the northern slope of the basin of Agchay, Qaracay and Babacay rivers. Lithologically they are represented by sequences of ribbon alternations of argillites, siltstones and sandstones (up to 400m) and occur in the Keivanian suite (between Xinaliq Dagi and Salavat Asirimi Pass (Salavat ashirim).
Upper Jurassic
During the Upper Jurassic a transgression covered new territories. In some areas restricted lagoons were formed. These deposits are present in the wings of the Tufan and Tengy-Besbarmaq anticlinorium and fill the syncline that separates them.
Callovian
The Lower Callovian deposits crop out in the north-west areas of the Zaqatala-Qovdag depression (Qovdag-Sumgayit zone). It forms the Zaqatala suite, composed by flysch alternations of flinty clays, siltstone and sandstones (up to 350m). In the Sudur zone, the Callovian deposits are transgressive on folded Aalenian rocks. This transgression is linked with the mid-Cimmerian tectonic event. The Callovian stage is absent within the north-eastern Azerbaijan deposits.
Oxfordian
The Oxfordian deposits are found in the interfluve of the Katekhchai–Cimicay rivers. Lithologically they are represented by interbeds of clays, sandstones, limestones and marls (300-800m). In the north-eastern regions isolated outcrops of the Middle-Upper Oxfordian can be found in the line stretching from Tengyaalti, Tekya, Cirax and Gulah villages as far as Besbarmaq. They are represented by carbonate rocks. In the Sudur zone, the Oxfordian rocks include gypsum interpreted as restricted, hypersaline lagoon deposits and clays.
Kimmeridgian
The Kimmeridgian stage is represented by mixed terrigenous and carbonate rocks in the southern slope of the Eastern Greater Caucasus. In the north-eastern area it is formed by reef-bearing facies. The Kimmeridgian deposits (up to 500m) consist in the lower parts of sandy limestones and in the upper parts of finely bedded limestones, marls, clays and sandstones. Reef-bearing formations in the north-eastern regions form good outcrops near the villages of Besbarmaq, Ciraxqala Dagi, Tekya, etc. Upwards in the section, limestones become massive and dolomitized (98m). In the Sudur zone the whole Kimmeridgian is represented by dolomite.
Tithonian
In the Eastern Greater Caucasus, deposits of the Tithonian stage are characterized by a sharp facial change. In the Zaqatala-Qovdag synclinorium the Tithonian stage is represented by argillites, limestones and sandstones (the Ilisu suite). A typical section of the Ilisu suite is located on the left bank of the Qaracay River. It is composed of thick bedded limestones, siltstones and clays (up to 430m). In the Sudur zone deposits are mostly sandy and argillaceous. In the Sahdag and Tengy-Besbarmaq zones the Sahdag facies is composed exclusively of bioclastic carbonate breccia. A standard section of the Sahdag facies is located in the southern cliff of the Sahdag Mountain. In its lower part lie grey, cross-bedded reef-bearing dolomitized limestones (225m) and in its upper part pink cross-bedded breccia in limestones and dolomites (nearly 550m). Thickness of Tithonian deposits in the Tengyaalti canyon is nearly 120m.
Mesozoic - Cretaceous
In the Eastern Greater Caucasus, Cretaceous deposits are mainly carbonate turbidites, terrigenous turbidites and slope facies. However in the Vandamian zone (southern slope) volcanogenic-sedimentary rocks of Albian-Cenomanian are developed. The deposits crop out in the central mountain range but are also exposed by drillings in the buried structures of Qusar-Davaci, Samaxi-Qobustan and middle-low Kura Trough (area of Abseron archipelago). Cretaceous deposits show a rapid facies change between the southern slope and the northern slope. This period is characterized by an unstable regime of sedimentation and that results in a frequent change from turbidite formations to non-turbidite ones. On southern slopes the Cretaceous deposits take part in all structures (Zaqatala-Qovdag and Vandamian zone).
Lower Cretaceous
Berriasian
Berriasian rocks are present in the southern slope and in the northern slope of the Eastern Greater Caucasus. The Berriasian covers two ammonites zones (the lower Spiticeras obliquenodosum zone and the upper Fauriella Boissieri zone). Outcrops in the north-eastern Caucasus can be observed in the axis zones of Tengy-Besbarmaq anticline and on the Sahdag-Xizi and Zaqatala-Qovdag syncline. They are part of the Qizilqazma suite. In the Sahdag and Sudur zones (NW), the Berriasian is represented by carbonate facies consisting of 70-100m dolomitic limestones. Facies of biogenic dolomitic limestones crop out also in the Tengy canyon and the Sohub section. Southward the lithological content changes and beds of clays, sandstones, coarse sandstones and clayey marls appear. In the Xizi zone (Uqah, Dagnacay Atacay sections), the Berriasian sediments transgressively cover the different horizons of the Middle and Upper Jurassic, with conglomerates at the base. In the region of Qonaqkand, Berriasian deposits are in tectonic contact with Middle Jurassic clayey shales. It is represented by bands (72m) of alternation of grey compact marls, breccia limestones, silty clays and fine to medium grained sandstones, grouped in packets of turbidite alternation. The Upper Berriasian is represented by cyclic alternations (40m) of grey, dark grey thin layered marly argillites, light-grey compact foliated marls, light-grey limestones and (rarely) sandstones. In Tengy-Besbarmaq anticlinorium and in Nardaran ravine (unlikely the same one as in Xizi), it is represented by a band of (96m) of alternations with carbonate sandstones, sandy and bioclastic limestones and marls grouped in packets of turbidite. Beds of conglomerate (up to 2-3m) are also common. In the Qovdag-Sumgayit zone, the Berriasian deposits crop out in the western area of Kheibericay (near Zarat-Kheybari)River and in the headwater of the Girdimancay River, where it is represented by thick sequences (up to 170m) of carbonate-terrigenous flysch, consisting of dark-grey carbonate argillites, limestones, marls, sandstones and coarse sandstones. The outcrops of Berriasian-Valanginian are fixed in the basins of Girdimancay, Dasagilcay, Sincay, Kescay, Muxax Cayi, Katexcay, Balakancay River. Here the Berriasian together with volcanogenics forms the Gora Kyupyuch-dag (Kepuch-dag)suite (400-700m), which overlies the Saki suite (Upper Jurassic). It consists of flysch alternation of bioclastic sandy and pelitic limestones, marls, argillite and rare sandstones.
Valanginian
Valanginian outcrops are developed in the same zone as the Berriasian. The Valanginian deposits gradually evolved from the Berriasian deposits. The upper area of the Babadag suite corresponds to the Valanginian stage. It is represented by a facies of light grey carbonate and terrigenous turbidite of the Gaitar suite (all along the southern slope of Eastern Greater Caucasus, northward of Qabala). According to ammonites (the lower Olcostephanus Drumensis zone and the upper Lamellaptychus Didayi zone), the Valanginian is divided into a lower and an upper substage. The Valanginian deposits in Sahdag and Sudur zones (Sahdag Mountain, Tahircal rivers and Tengy canyon) are represented by a band (100m) of grey, siliceous, bioclastic, dolomitic limestones. In the western and south-western area of Xizi syncline the sections consist of alternations of clays, sandstones, limestones and marls up to 200m thick (Fig. 18). On the Gora Kelevu Mountain the Lower Valanginian is represented by a sequence (40m) of alternations of dark-grey, grey marly argillites, orange-brown, bedded marls and grey platy limestones. The lower part of the Upper Valanginian is represented by interbeds of dark-grey, grey marly argillites, grey marls and grey, and locally by platy limestones and conglomerates (5-10m). The upper level (40m) is composed by dark grey, marly argillites with interbeds of grey fragmental marls. Close to Besbarmaq Mountain in the Nardaranian sections of the Kescay and Atacay rivers, there are deposits of pelitic sandstones, coarse sandstones and conglomerates. In the Nardaran ravine the conglomerates are grouped in packets up to 6-10m. They consist of pebble fragments and Triassic blocks. Other components of the coarse turbidites (up to 30m) are silty marls, bioclastic-sandy-oolitic limestones, carbonate sandstones and coarse limestone with thin interbeds of marly argillites with radiolarians. In the eastern segment of the Zaqatala-Qovdag Trough, the deposits of Valanginian are very similar to those of the Xizi Trough. In the headwaters of the Girdimancay and Pirsaat rivers they are represented by thick (up to 500m) carbonate-marl-argillite turbidite sequences with rich microfauna. In the Vandamian zone (southern slope of the Greater Caucasus), Berriasian-Valanginian sequences in the Eastern territory (Ahohcay River) consist of sandy bioclastic limestones, sandstones, conglomerates and carbonate breccia. Westward, in the basins of the Dasagilcay, Kescay and Sincay rivers, the predominance of limestones and breccia decreases in Berriasian-Valanginian sections. At Bas Dasagil River these deposits are represented by siliceous limestones, shale clays, argillites with rare interbeds of sandstones (300m).
Hauterivian
In the Eastern Greater Caucasus deposits of Hauterivian stage are widespread except in the northern slope (Sahdag and Sudur subzones). In north-eastern part of Tengy-Besbarmaq anticline, it is represented by carbonate facies and in all other parts by clayey facies. In the south-east area, the upper part of the Kaitar suite corresponds to the Hauterivian stage and the lower part to the Valanginian stage. In Sahdag and Sudur zones the Hauterivian stage deposits (up to 100m) differ from the underlying Valanginian limestones by the appearance of clay and sandstone beds. In all studied sections of Xizi zone and also on the southern wing of Tengy-Besbarmaq anticline, the lithofacies of Hauterivian deposits are significantly uniform. They are mainly dark grey clays with interbeds of sandstones, limestones and marls. Their common thickness is about 300m in Gora Kelevu Mountain and 700m in Sitalcay. The more typical section of Hauterivian can be observed on Gora Kelevu Mountain where it is divided in two substage: the Lower Hauterivian represented by a band (95m) of dark-grey, grey marly argillites with rare interbeds of thin-layered marls and carbonate sandstones and the Upper Hauterivian corresponding to sequences (150m) of dark-grey, marly argillites with interbeds of carbonate sandstones and marls. In eastern segment of Zaqatala-Qovdag zone, the Hauterivian deposits are similar to those of Xizi zone. In the most western area of Qobustan, in basin of Pirsaat and in Girdimancay-Pirsaat watershed, the Hauterivian is represented by dark grey marly argillites and argillites with frequent interbeds of sandstones, limestones and rarely coarse sandstones. In Vandamian zone (Gurbulaq suite), it consists of alternation of clayey shales with interbeds of sandstones and limestones (60-300m).
Barremian
In south-eastern Caucasus Barremian sediments are widespread in all tectonic zones. They gradually evolve from the underlying Hauterivian deposits. The Khalcay suite (north of Sahnazardag (Shakhnazardag)) corresponds to the Barremian stage, which is represented by clayey facies, except in Sahdag subzone, where these deposits are represented by carbonate rocks with interbeds of clays. These deposits are divided into two substages: the Lower and Upper Barremian based on ammonite zones (the lower Holcodiscus Caillaudianus zone and the upper Phyllopachceras Ectocostatum zone). In Sahdag and Sudur zones Barremian (90-180m) is represented mainly by light grey limestones with beds of clays in middle part of the section. In Xizi and Qovdag-Sumgayit zones, the Barremian is represented in monotonous clayey facies. The section (335m) of Gora Kelevu Mountain is typical for these zones. Here rare interbeds of sandy limestones and marls but also blocks (up to 2m) of Jurassic limestones can be observed. Towards the south-east the Barremian deposits have the same facies as in Sahdag and Sudur zones, and only around the Besbarmaq appear cordylite interbeds of coarse sandstones and conglomerates. In this direction deposits gradually increase up to 600m (Dagnacay River), 620m (Atacay River) and 885m (Qizilqazma River). In eastern area of Qovdag-Sumgayit zone near Altiagac Mountain (215m), Dubrar Mountain (415m), Giyadisu (east of Gadi dagi mountain) (more than 425m) the Barremian consists of grey marly argillites with rare interbeds of limestones and marls. In this area inside of clayey thickness of Barremian exotic blocks of the Upper Jurassic limestones are observed. On Girdimancay-Pirsaat watershed near Zarat-Xeytari village, Barremian consists of clays with interbeds of marls, sandstones and limestones. In the Barremian section of Zaqatala-Qovdag zone appear interbeds of argillites and marls. They have a general thickness from 175 to 386m. In Vandamian zone Barremian corresponds to Candov suite (150-450m). It consists of alternation of light-grey limestones, marls, sandstones, clays and coarse sandstones.
Aptian
Deposits of Aptian stage crop out in the Xizi, Zaqatala-Qovdag-Sumgayit, Tengy-Besbarmaq zones and they were also discovered in drillings. In Sahdag and Sudur zones theses deposits were removed by the Pri-Caspian erosion. The Aptian lithofacies is similar in all regions. The Septarian horizon and Khanaga suite correspond to the Aptian stage. In the Eastern Greater Caucasus, Aptian is faunistically subdivided into three substages : the Lower, Middle and Upper Aptian. In Xizi zone (section of Gora Kelevu Mountain) the Lower Aptian (40m) is represented by greenish-grey, strong marly argillites with interbeds of marls and sandstones. Middle Aptian (45m) is represented by reddish-brown marly argillites with interbeds of marls (Fig. 19). The most complete sections of Aptian are known in south-eastern sections (basin of Atacay River) where clays contain abundant remains of belemnites. The clayey facies of Aptian with rich macro- and microfauna remains can be observed in Qovdag-Sumgayit zone in basins of Carxacicay (Jarkhachicay River (198m), Tudar River (191m), Giyadisu (east of Gadi dagi mountain) River (212m) and on Dubrar Mountain (152m). Here the Lower Aptian is represented by greenish-grey clays with marly septarias and numerous belemnites. Middle and Upper Aptian consist of grey, red, greenish and yellowish marly argillites. They contain together with the above mentioned belemnites, the Middle-Upper Aptian species as well. Towards north-west in sections of Zarat-Xeytari (150m) and Girdimancay-Pirsaat rivers watershed (240m), appear interbeds of sandstones and sandy limestones, usually without organic remains. Kohnadahar suite (Lower Aptian) and the Agbulaq suite (Middle-Upper Aptian) correspond to the Aptian stage in the Vandamian zone. In Girdimancay River Basin, the Kohnadahar (Kokhnadahar village) suite is represented by band of siltstone, limestones, sandstones and argillites. Agbulaq suite is represented by multicolored deposits (up to 50m) corresponding to an alternation of limestones and siliceous argillites.
Albian
In the south-eastern Caucasus Albian deposits are widespread in the same zones as the Aptian deposits and usually they are concordantly bedded on them. Altiagac suite horizon of Kulullusandstones (but main outcrop is near Altiagac (means 6 trees) and Auceline (microfauna name) horizon correspond here to the Albian stage. In central area of Xizi and Qovdag-Sumgayit syncline, the Albian section is complete and expressed by all three substages. In area of Qonaqkand village, the Lower Albian (28m) is represented by clays with interbeds of sandstones and shales. The Middle Albian (30m) is represented by the same rocks. The Upper Albian (50m) consists of turbidite alternation of clays, sandstones and marls. In central part of Qovdag-Sumgayit zone, the Albian is represented in the lower part (25-60m) and in the middle part (50-60m) by clays with interbeds of sandstones, and the in upper part (50-60m) by clays, marls, sandstones and limestones. In section of Dubrar Mountain and in area of Takhta-Yailag (plateau south of Dubrar Mountain) all three Albian substages are known. Their presence can be deduced by finds of belemnites, foraminifers and radiolarians. In sections of Girdimancay River the Albian deposits are subdivided in two parts: the lower part (85-90m) represented by clays and limestones and the upper part (30m) represented by clayey-sandy deposits with remains of foraminifers. Within Vandamian zone the main part of Albian section (from 200 to 600m) is composed of tuffaceous rocks (Fig. 20). The deposits of Lower-Middle Albian are Lahic suite and the upper Culyan (Julyan) suite. The more complete section of Albian can be observed on Sulutcay and Girdimancay rivers where it is represented by alternation of argillites, tuffaceous rocks and (rarely) by siliceous limestones, where foraminifers can be found.
Mesozoic - Upper Cretaceous
Upper Cretaceous deposits are characterized by monotonous lithofacies rich in ammonites, belemnites, inocerams, echinoderms, corals, foraminifers, ostracodes and radiolarians. Upper Cretaceous outcrops are confined to the same structural zones as the Lower Cretaceous outcrops. In the northern slope (Sudur zone and Sahdag subzone) carbonate platform and slope deposits with turbidites have been mainly accumulated. In the southern area (Xizi and Qovdag zone) mainly turbidite deposits have been amassed. In Sudur zone, the Upper Cretaceous is bedded unconformably on the Lower Cretaceous and is represented by thin terrigenous-carbonate sediments. In Sahdag and Tengy-Besbarmaq zones the Upper Cretaceous is represented mainly by carbonate rocks and is characterized its continuity with a significant thickness (up to 2200m) of turbidite deposits with prevalence of clayey rocks.
Cenomanian
Deposits of Cenomanian stage crop out in Xizi and in Qovdag zones. In many sections (Gora Kelevu, Dubrar and others) Cenomanian deposits gradually evolve from the Albian deposits. In Tengy-Besbarmaq Zone, Cenomanian deposits are discovered by drillings and they consist of dark-grey, greenish-grey-clays, fine-grained sandstones, limestones and conglomerates (55-90m), with rare interbeds of tuffs and carbonate tuffites. In Sahdag-Xizi Zone isolated outcrops of Cenomanian deposits can be observed. In Buduq Trough, on Chulgazidag Mountain (near Zuxur village), they are transgressive on eroded horizons of Albian and are covered unconformably by conglomerate of the Upper Turonian. They are represented by carbonate and terrigenous turbidites (up to 50m) consisting of grey clays with interbeds of limestones, carbonate sandstones and small pebble conglomerates. In Xizi section of Gora Kelevu Mountain the Lower Cenomanian (20-22m) is represented by alternation of grey, dark grey fragmental, marly argillites, bioclastic, sandy limestones with interbeds of marls and finally thick-plated carbonate sandstones with rare interbeds of carbonate coarse sandstones. The Middle and Upper Cenomanian (20m) is represented by alternation of small pebble conglomerates, coarse sandstones and carbonate sandstones with thin interbeds of clays. In Qovdag zone the lithological content of Cenomanian deposits is close to the same age deposits of Xizi zone. They differ from these by distinct thickness (300-330m) and a reduction of small pebble conglomerates. The most complete section of the Cenomanian deposits crops out in Dubrar Mountain. Lithologically the section is composed by sandy-clayey carbonate bands (up to 300m) and characterized by rich complexes of benthos, planktonic foraminifers, radiolarians and pollens. In the region of Takhta-Yailag (plateau south of Dubrar Mountain), the Cenomanian is represented by the same facies. In the north-eastern area of the basin of Pirsaat River near Zarat-Xeytari village, the thickness of Cenomanian significantly reduces (65-70m) and is represented by a band of limestones, clays and marls, containing microfossils. Southward in the valley of Saridaghcay River (south of Xaltan Asirimi (Khaltan ashirim) pass), the Cenomanian is represented by interbeds of grey, grey limestones, thin sandstones and marls with thin interbeds of marly argillites. In the Gyadysu River Basin the Cenomanian corresponds to a band (90m) of white grey clays, marls, sandstones and limestones.
Turonian
Turonian deposits are concordantly bedded above the Cenomanian. Lithologically the Turonian is represented by two different facies: the Lower Turonian and Upper Turonian facies. The Lower Turonian stage, corresponding to Zarat Xeytari horizon, is represented by bands of limestones, marls, marly argillites and sandstones with interbeds of shales. The Upper Turonian is represented by carbonate facies. The Upper Turonian and the Coniacian are considered together due to their lithological similarity and poor paleontological remains. Turonian sediments are not dispersed uniformly. In the northern slopes, Turonian deposits are exclusively represented in Xizi and Dubrar zones (Fig. 24). In section of Gora Kelevu Mountain the Lower Turonian deposits are represented by interbeds (up to 30m) of compact, grey plate marls, limestones, argillites and in some place by black clays. The Upper Turonian is represented by a sequence (17m) of grey, dark-grey clays, limestones, marls, conglomerates and sandstones. In Qovdag zone the Turonian is concordantly bedded on Cenomanian and is represented by a terrigenous-carbonate turbidite facies. On Dubrar Mountain (Fig. 23) the Turonian deposits are divided into two substages. The Lower Turonian deposits consists of alternation (26-28m) of greenish-grey, reddish-brown marly argillites, light grey layer compact limestones and sandstones with occasional interbeds of purple-violet clays. The Upper Turonian is represented by cyclic alternation (47-49m) of greenish-grey, brown clays, marls, light-grey crystallized limestones evolving in coarse sandstones and fine-pebble conglomerates.
Turonian deposits are present along the Qozlucay River section and stretch as narrow stripes to the west and crop out in basin of Cigilcay, Pirsaat and Girdimancay Rivers. In the most westerly area of Qobustan, in the area of Zarat-Xeytari village, the Turonian deposits are represented by cyclic alternation of various colored (in some place cross layered) limestones, marly argillites and marls. In such facies the Turonian is represented in the basin of the Saridaghcay River (south of Xaltan Asirimi (Khaltan ashirim) pass). Eastward the Turonian deposits are recorded in the region of Takhta-Yailag (plateau south of Dubrar Mountain) area and along the right bank of Ambizlyar River. In both section the Lower Turonian (up to 40m) is characterized by turbidite alternation, light grey marly argillites. In Upper Turonian (40m) beds contain compact marls in addition to the turbidite components.
Coniacian
Deposits of Coniacian stage concordantly cover the Turonian deposits. Coniacian deposits are represented by clayey marls and carbonate facies. Foraminifers, radiolarians and rare inocerams occur in the lower part. In Sudur and Sahdag zones, outcrops of Coniacian deposits are unknown. Within Xizi zone the Coniacian deposits have been preserved from Pri-Santonian erosion in Buduq Trough. They are represented by carbonate-terrigenous turbidites composed of grey pinkish clays, sandy limestones, marls with rare interbeds of fine pebble conglomerates. In section of Gora Kelevu the Coniacian stage is represented by both substages. The Lower Coniacian (45m) is represented by light-grey clays, marls and limestones. In the base of Upper Coniacian (15m) massive sandstones appear and small pebble conglomerates and interbeds of conglomerates on the top. In Qovdag zone the deposits of Coniacian stage are concordantly bedded on the rocks of the Upper Turonian and are represented by turbidite facies. In the basin of Pirsaat River near Zarat-Xeytari village, the Coniacian corresponds to a band (40m) with alternation of grey, dark-grey compact marly argillites, grey layer marly limestones and marls. The Upper Coniacian is represented by a band (75m) of rhythmic alternation of grey, dark-grey marly argillites, different grain size limestones, marls with rare interbeds of lense sandstones. The same facies of Coniacian can be observed in the basin of Saridaghcay River (south of Xaltan Asirimi (Khaltan ashirim) pass), where the thickness of deposits is reduced to 60m. In section of Dubrar Mountain the Lower Coniacian deposits correspond to turbidites formations (75m) with light-grey, brown, greenish-grey marly argillites, marls, limestones and sandstones. The Upper Coniacian is represented with the same facies as the Lower Coniacian, but its thickness is reduced almost by a factor two. Towards the south, in Takhta-Yailag (plateau south of Dubrar Mountain) area, the Lower Coniacian (70m) is also represented by carbonate facies with microfauna. The Upper Coniacian (40m) is lithologically the same. In the Giyadisu River (east of Gadi dagi mountain) Basin, Coniacian stage (50m) is represented by rhythmic alternations of brown, greenish-grey clays, light-grey limestones and marls and rarely small-pebble conglomerates.
Santonian
Santonian deposits are concordantly bedded on Coniacian. They are represented by terrigenous and carbonate facies with prevalence of clayey rocks. Foraminifers, rare belemnites and inocerams indicate an Upper Santonian deposit. In Sudur, Sahdag and Tengy-Besbarmaq zones these deposits are unknown. Santonian deposits are widespread in Xizi zone. They are bedded on the Upper Coniacian deposits and in some places on different horizons of the Lower Cretaceous. In section of Gora Kelevu Mountain, the Santonian stage is represented by a band (52m) of light-grey, grey massive limestones with interbeds of fine-grained conglomerates. In Zaqatala-Qovdag zone the Santonian deposits are concordantly bedded on Coniacian deposits and lithologically differ by an increase of clay thickness and by a prevalence of brown color. In Dubrar Mountain section the Lower Santonian is represented by a band (82m) of rhythmic alternations of reddish-brown, greenish-grey marly argillites with interbeds of grey, greenish-grey carbonate sandstones and limestones and also (rarely) fine conglomerates and coarse sandstones. The Upper Santonian corresponds to a band (77m) of rhythmic alternations of greenish-grey, pinkish-brown compact sandy clays with interbeds of grey limestones. In section of Zarat-Xeytari (50m) and Takhta-Yailag (plateau south of Dubrar Mountain) (64m) the Upper Santonian is lithologically almost monotonous and is represented by interbeds of clays, marls and limestones with prevalence of clays. In the south-east the outcrops of Santonian deposits can be observed in the Giyadisu River (east of Gadi dagi Mountain)Basin (80m). They are represented by red marly argillites with interbeds of white-grey marls.
Campanian
Deposits of Campanian stage are widespread in all troughs and are represented by the same facies as the Lower Santonian deposits but their thickness significantly increases (up to 215m). In the Campanian deposits, belemnites, bivalves and foraminifers are widespread and allow to distinguish the Campanian substages. In Sudur and Tengy-Besbarmaq zones, the Lower Campanian deposits are transgressive. Their basal conglomerates are bedded on the Upper Barremian rocks (Fig. 25). In Sahdag zone, at the base of the Upper Cretaceous section, the deposits of Lower Campanian cover unconformably the Barremian and Aptian rocks with, in some areas, a coarse conglomerates facies at the base. In Sahdag Mountain area the Lower Campanian (6m) is represented by clays with rare interbeds of limestones and marls. The Upper Campanian deposits correspond to interbeds of limestones, marls and clays, containing rich fauna of belemnite and foraminifers as well. Their thickness is 144m. In Xizi zone, conglomerates are also observed in the base of Campanian.
Campanian sediments cover the Santonian deposits and different horizons of Cretaceous. On Gora Kelevu Mountain the Lower Campanian (30m) is represented by a band of pelitic limestones, sandstones, marls and clays. The Upper Campanian (34m) is represented by interbeds of sandy limestones, marls, clays with foraminifers and radiolarians (sample AZ059 Fig. 26). The Campanian deposits in Qovdag and Dubrar zones are widespread and have similarities with those of Xizi zone, differing by the prevalence of clayey rocks. On Dubrar Mountain, the Lower Campanian has, in the base, fine pebble conglomerates (0-4m) and is represented by a band (52m) of alternations of white-grey, greenish-grey and red marly argillites with common interbeds of marls, carbonate sandstones and compact limestones with abundant remains of foraminifers. The Upper Campanian is represented by a band (50m) of turbidite alternations of grey, greenish marly argillites, plated sandstones, layered marls and limestones. Southward, in section of Takhta-Yailag (plateau south of Dubrar Mountain)area and of the Cigilcay River basin the thickness of clayey beds significantly increases. In Qovdag zone, the Campanian deposits (up to 80m) are lithologically close to Dubrar facies and crop out in the basin of Pirsaat River in the region of Zarat village. Good outcrops of Campanian deposits can be observed within Sahdag zone structures, on Sahdag Mountain. Here, the lower substage is represented by a sequence (80m) of alternation of grey, greenish-grey, sometimes red-brown marly argillites, white-grey, pink-marls and fine grained sandstones. The Upper Campanian (60m) is represented by the same facies as the Lower Campanian.
Maastrichtian
Maastrichtian deposits are bedded concordantly on Campanian. Faunistically they are characterized by ammonites, belemnites, inocerams and foraminifers. Thin conglomerates of Lower Maastrichtian remain in Sudur substage. The pebbles of these conglomerates have removed Aptian-Albian mollusc fauna. In Tengy canyon (Tengy-Besbarmaq zone), Lower Maastrichtian deposits are represented by a band (67m) of alternations of grey-sandy limestones, dark grey marly argillites with rare interbeds of small-pebble conglomerates. In the upper part the clays are substituted by sandy marls. In the south-eastern zone Maastrichtian deposits can be observed along the Caspian Sea coast near Suraabad village. They are represented by an accumulation (260m) of light-grey marls and marly clays. In Sahdag-Xizi zone Maastrichtian deposits have been preserved in some section of Xizi Trough as a result of recent erosive cut. In Sahdag substage (Sahdag Mountain) the section of Lower Maastrichtian (25m) consists of bioclastic limestones with interbeds of clays, sandstones and marls. In Xizi substage in the Buduq Trough (Chulgazidag Mountain (near Zuxur village)) the Maastrichtian deposits consist of clayey-carbonate deposits with interbeds of marls, sandstones and fine-pebble conglomerates. On Gora Kelevu the deposits of Maastrichtian stage are represented only by the lower substage. They consist of a band (35m) of limestones, marls and clays with interbeds of sandstones. In Qovdag and Dubrar zones Maastrichtian deposits are widely developed and connected with Campanian by gradual transition. Lithologically, there is an increase of terrigenous material content compared to the Campanian deposits. In the section of Dubrar Mountain, the Maastrichtian stage (70m) is represented by turbidite alternations of grey, greenish-grey clays, marls and sandy limestones. In some places, this kind of deposit is replaced by fine-pebble conglomerates. Dubrar turbidites facies of Maastrichtian can be observed in outcrops of the basins of Cigilcay (Takhta-Yailag (plateau south of Dubrar Mountain)section) and Tudar rivers (Ambizlyar Trough). They differ only by some increase of sandy limestones interbeds. The complete section of Maastrichtian crops out in the area of Diyalli village, where the Lower Maastrichtian (85m) is represented by interbeds of marls, limestones and clays. The Upper Maastrichtian (50m) is represented by the same facies as the lower, but fine-grained conglomerates can be observed at the top.
Tertiary Paleogene
Paleogene deposits of the Eastern Greater Caucasus have different lithologies: sedimentary, volcanogenic-sedimentary and volcanogenic. These deposits have an important thickness and take part in the construction of numerous tectonic units. They are also largely represented in other parts of Azerbaijan (Lesser Caucasus, Kura depression and Talysh Mountains). Tracing of the distribution of Paleogene deposits and clarification of their stratigraphic position in Azerbaijan can help solve problems of correlation with the Mediterranean-Alpine Paleogene deposits.
Paleocene
In the Eastern Greater Caucasus, accumulation of the Paleocene deposits took place in a marine basin. Transition from Maastrichtian to Paleocene stage was marked by a regional rise in the NE and SW of Azerbaijan and also by an important downwarping of the central part of the basin. This downwarping was not constant and varies in space and time. The depth of the basin varied frequently from the coastal to shallow water. The smallest depths areas in the Paleocene basin are the west part of the Pri-Caspian-Quba, the Ganca and Muradhanly regions. The deepest area was located in the Abseron Peninsula and in the Central and South Qobustan (at least 5000m of sediments). The presence of some kinds of nummulites and foraminferas are in favor of a mainly warm climate with certain intervals of hot climate close to tropical. In the north-eastern area, the Paleocene deposits are composed of shales of polymineral composition. Within the Buduq Trough bands of coarse sands with interlayers and lenses of conglomerates occur. In the South Eastern area, deposits acquire a clayey character and in the Samaxi-Qobustan area, they are enriched sandy material again.
Eocene
Eocene deposits are widespread in Azerbaijan. Stratigraphically they are divided into three parts. The geotectonic surroundings of the sedimentation basin were nearly the same as during the Paleocene. Only the Tufan - Sahdag zone surroundings suffered considerable contraction since Lower Eocene.
The Lower Eocene is characterized by terrigenous deposits. They conformably lie on the Upper Paleocene deposits. Their formation took place in a relatively deep marine basin.
The facies of the Middle Eocene deposits shows an explosive activity of the volcanic zones of the southern flank together with a wide transgression. There is sedimentation of the volcanic eruptions products. Their lacks in the Pri-Caspian region, probably, demonstrate the role of the Sahdag uplift as a barrier on the possible way of the volcanic material to the Lower Eocene Basin. The main sources of the removal material were the Greater and Lesser Caucasus and the centers of volcanic eruption.
Oligocene
The deposits of Maikopian suite (Fig. 27) are common in Azerbaijan. They consist of grey and brown compact (occasionally laminated) slightly marly argillites having fish and plant remains as well as thin interbeds of marls, dolomites, clayey shales and siderite concretions. Sediments were accumulated in a shallow sea basin. This basin became shallower towards the uplifted part of the Pri-Caspian-Quba area as well as toward the northern slopes of the Lesser Caucasus and the Talysh Mountain system. The depositional environment was coastal towards the northern slopes of the Lesser Caucasus. The deepest portion of this basin was located in the Abseron peninsula and northern Qobustan. The Maikopian Basin properties promoted the accumulation, the burial and the transformation of organic matter into oil hydrocarbons. Accordingly, the Maikopian deposits are famous for being a productive sequence of hydrocarbon.
Tertiary - Neogene
Miocene
The formation of these deposits was determined by conditions that prevailed in the sedimentary basin as well as by the tectonic regime. The depositional environments were continental, shallow-coastal, moderate-deep marine and deep marine.
The continental facies consists of coarse rocks (conglomerates and coarse sandstones) and occasional sandy-silty formations. It prevails in Azerbaijan between the Kura and Qabirri zone.
The shallow coastal facies occurs in the border part of the Kura depression and consists of coarse and fine-clastic rocks. The reason of wide distribution of coarse rocks is the accumulation of continental facies sediments in the coastal part. As for the fine-clastic rocks, their formations were caused by a disintegration of the sedimentary rocks of the Greater Caucasus and the volcanogenic rocks of the Lesser Caucasus. Besides, elevations in the sedimentary basin might have caused the removal of these rocks.
Based on fauna and facies, different water depth facies have been determined. The moderate deep water facies is characterized by the presence of a sandy-shaly lithofacies having interlayers of marls. The deep water facies consists chiefly of shaly formations with thin interlayers of fine-clastic rocks. It is mostly developed in the central part of the Evazli-Agcabadi Trough.
The Pontian stage (~7 Ma) is common in the south-eastern Caucasus (Pri-Caspian – Quba area), the Samaxi – Qobustan area, the Lower Kura depression and in the interfluve of the Kura and Qabirri rivers. This stage is everywhere bedded unconformably on older deposits of Miocene (Abseron peninsula, Qobustan and Samaxi region), on Oligocene deposits (Samaxi-Qobustan area, interfluve of Agsu-Goycayand on Upper Cretaceous deposits (Pre-Caspian-Quba area).
In the Pre-Caspian-Quba area, the Pontian deposits crop out in the Qudiyalcay River valley near Kusnatqazma village. Lithologically they are represented by sequences (300m) of dark grey, bluish-grey striped clays with interbeds of sands and sandstones. They are bedded unconformably on the Cretaceous deposits.
In the Samaxi-Qobustan region the Pontian deposits (Fig. 28) are represented by limestones rich in shells, rocks compact sandstones and sandy clays. Here the middle and upper horizon have remained. They differ lithologically from the lithofacies of the Abseron peninsula.
In the Abseron Peninsula they are represented by a deep water facies. The lower substage is lithologically represented by dark grey, shale clays, and brown clayey interbeds. The Middle Pontian deposits are more developed than the lower substage and they are represented by alternation of dark-grey, light-brown stripped clays within interbeds of silt and volcanic ash. The Upper Pontian substage is represented by grey, dark-grey compact shaly clays, and interbeds of clayey limestones and shell rocks.
The Pontian shale strata may be potentially oil prone. However there is no occurrence of oil and gas fields in Pontian deposits due to hydrocarbon migration. The limestones of Samaxi-Qobustan zone have been used as a building material for a long time.
Pliocene
The Lower Pliocene deposits are widespread in Azerbaijan. It is a mass consisting of alternating layers of sandy-silty and shaly rocks that occurs between faunal characterized Pontian and Akchagylian deposits. The productive sequence consists of coarse non-sorted and pyroclastic, sandy, silty and shaly rocks with a cyclic structure. Their thickness is up to 5000m. Depending formation conditions of the Pliocene deposits, there are four different facies: continental, shallow coastal (up to 50m deep), shallow (50-200m deep) and relatively deep (up to 1000m). They contain numerous turbidite deposits. All these facies crop out in the different zones (Abseron peninsula, Qobustan area, Pre-Kura area, South Caspian Basin and Pre-Caspian Basin).
The eroded terrigenous material came from principal and secondary relief as the Russian platform, the Greater and Lesser Caucasus and the Talish Mountain.
The Upper Pliocene deposits of the Akchagylian stage play an important role in the geological structure of Azerbaijan major oil and gas bearing area. The abundance of these deposits in Azerbaijan's rocks is accounted to the Akchagylian transgression. It began as early as the Late Pliocene period and reached its peak in the Upper Pliocene. Therefore the boundaries of the Caspian Sea extended considerably. In the Middle Pliocene period, the major sinking zones were linked to the Terek-Caspian Trough, the South Caspian depression and the west Turkmenian depression.
In spite of a steady tectonic regime, volcanic activity took place in the peripheral parts of the depression. The evidence of this activity is the presence of interlayers of volcanic ashes in the Akchagylian deposits. Even if a regression took place at the end of the Akchagylian and Abseron ages, it was insignificant.
In the Kura depression, the shores of the Akchagylian Sea overlapped not only the shores of the Early Pliocene Basin but also those of the older basins of the Miocene Sea (including the Pontian Sea) and in some places even those of the Paleogene Sea. For this reason, the Akchagylian deposits transgressively lie on older deposits along the border of the Kura depression. In the buried structures of the Kura depression, the productive sequences are overlapped by the Akchagylian stage without any significant signs of breaks and unconformity. In the Pri-Caspian-Quba lowlands (in the country between the Samur River and the Valvalacay River, the Akchagylian stage consists of shallow marine and fresh water facies while in the country between the Davachicay and the Gigilcay it consists of a deep water clayey facies. In the Abseron Peninsula, Eastern and Central Qobustan and the south-eastern part of the Pri-Caspian-Quba lowland, the Akchagylian section consists of the same facies having interlayers of volcanic ashes.
Hydrocarbon accumulations have been discovered in the Akchagyl deposits of the Pri-Kura area. These local reservoirs are located in some anticlinal uplifts. Here the hydrocarbon is accumulated in granular reservoir rocks alternating with clayey facies.
Quaternary
The Pleistocene is characterized by the formation of different basins in the regions around the Eastern Greater Caucasus and is represented by molasses-type deposits and expressed by marine, continental and transitional facies. The Greater Caucasus and the Lesser Caucasus were the main sources for clastic products. They were constantly rising and the rate of this uplift increased all the time. There are also periodic deposits of volcanic activities.
The thickness and widespread of Pleistocene deposits are due to an intensive marine and continental sedimentation, tectonic construction (begun in early Pleistocene) and volcanism. They are mostly spread in the intermontane depression (Pri-Kura lowland, Baku archipelago), in the south-east slope of the Greater Caucasus (Qobustan, Abseron Peninsula, Abseron archipelago), and in the frontal depression (Lankoran lowland). The deposits reach a thickness of up to 1200m in the intermontane depression and up to 2000m in the adjacent South Caspian Basin.
Oil- and gas-bearing deposits are confined mainly to the deep marine deposits in the eastern part of the Kura depression.