Kuban Basin Research Articles

Debris cover effect on the evolution of Northern Caucasus glaciers in the 21st century

More than 13% of the area of the Caucasus glaciers is covered by debris affecting glacier mass balance. Using the Caucasus as example, we introduce a new model configuration that incorporates a physically-based subroutine for the evolution of supraglacial debris into the Global Glacier Evolution Model (GloGEMflow), enabling its application at a regional level. Temporal evolution of debris cover is coupled to glacier dynamics allowing the thickest debris to accumulate in the areas with low velocity. The future evolution of glaciers in the Northern Caucasus is assessed for five Shared Socioeconomic Pathways (SSP) and significance of explicitly incorporating debris-cover formulation in regional glacier modeling is evaluated. Under the more aggressive scenarios, glaciers are projected to disappear almost entirely except on Mount Elbrus, which reaches 5,642 m above sea level, by 2,100. Under the SSP1-1.9 scenario, glacier ice volume stabilizes by 2040. This finding stresses the importance of meeting the Paris Climate Agreement goals and limiting climatic warming to 1.5 °C. We compare evolution of glaciers in the Kuban (more humid western Caucasus) and Terek (drier central and eastern Caucasus) basins. In the Kuban basin, ice loss is projected to proceed at nearly double the rate of that in the Terek basin during the first half of the 21st century. While explicit inclusion of debris cover in modeling leads to a less pronounced projected ice loss, the maximum differences in glacier length, area, and volume occur before 2,100, especially for large valley glaciers diminishing towards the end of the century. These projections show that on average, fraction of debris-covered ice will increase while debris cover will become thinner towards the end of the 21st particularly under the more aggressive scenarios. Overall, the explicit consideration of debris cover has a minor effect on the projected regional glacier mass loss but it improves the representation of changes in glacier geometry locally.

Climate Change Effects on River Flow in Eastern Europe: Arctic Rivers vs. Southern Rivers

The hydrological model ECOMAG was used to calculate runoff characteristics in the main arctic (Northern Dvina and Pechora) and southern (Don and Kuban) river basins of Eastern Europe using the data from the ensemble of global climate models under the scenario of 1.5 and 2 °C global warming in the 21st century relative to pre-industrial values. Flow generation models were calibrated and validated based on runoff measurements at gauging stations using meteorological observation data. According to the results of numerical experiments, the relative change in river runoff in European Russia increases from north to south and from east to west under global warming of 1.5 to 2 °C. As a result, hydrological systems in milder climate were found to be more vulnerable to climate change. The assessment of flow anomalies in European Russia under the selected climate scenarios revealed the following general features: winter runoff in arctic rivers would increase, spring melt runoff in the Northern Dvina and Don would decrease, and summer–autumn runoff in all studied rivers would decrease to varying degrees. The most negative runoff anomalies are characterized in the southwestern part of the Northern Dvina basin, the middle part of the Don basin, and the lowland part of the Kuban basin, whereas positive runoff anomalies are characterized in the northern and eastern parts of the Pechora basin. Global warming of 1.5 to 2 °C would have the greatest impact on the rate of reduction of Kuban summer–autumn runoff and Don runoff during the spring flood, as well as the increase in Northern Dvina and Pechora winter runoff.

ВЫПУСК МОЛОДИ ОСЕТРОВЫХ В АЗОВО-КУБАНСКОМ РАЙОНЕ С РЫБОВОДНЫХ ЗАВОДОВ ФЕДЕРАЛЬНОГО АГЕНТСТВА ПО РЫБОЛОВСТВУ В ПЕРИОД С 2016 ПО 2022 Г.

Background. By the end of the 20th and the beginning of the 21st century, artificial reproduction had taken up a key role in the sturgeon stock recruitment in the natural water bodies of the Azov–Kuban region. Relevance. The major part of artificial reproduction of sturgeon species is conducted in the fish hatcheries of the Azov–Kuban region under the authority of the Federal Agency for Fishery (Rosrybolovstvo). The aim of this study was to analyze the volumes of rearing and release of juvenile sturgeons into water bodies of fisheries importance in the Azov–Kuban region by fish hatcheries subordinate to the Federal Agency for Fishery. Methods. This article is based on the data recordings of the Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”) for the time range from 2016 through 2022. The data on 4 sturgeon hatcheries— Adygea, Achuevo, Grivensk, and Temryuk—are presented and analyzed. Results. An increase in the total number of juveniles of sturgeon species released into the natural habitat has been revealed. The highest values were recorded in 2021–2022. There has also been a disproportion in the number of released juveniles belonging to different species. Each year, sterlet Acipenser ruthenus accounted for a large share of released juveniles, for which the percentage ranged from 47.6 % in 2018 to 64.4 % in 2022. In recent years, the volumes of rearing and releasing the juveniles of this species have been increasing both quantitatively and in percentage terms. This fact can be explained by the earlier maturation of sterlet breeders, shorter intervals between repeated spawning, and the resultant larger number of “active” breeders of this species in the hatcheries. From 2019 through 2022, the share of the juveniles of sturgeon species released by the hatcheries of the Federal Agency for Fishery into the Protoka River, as compared to the Kuban River, increased from 55.0±0.10 % in 2016–2018 to 68.9±0.44 % (2019–2022). It resulted from the increase in the number of the sturgeon juveniles released into this water body, and not from a redistribution of release volumes between the Kuban and Protoka Rivers. Conclusion. In general, the artificial reproduction of sturgeon species by the fish hatcheries of the Federal Agency for Fishery in the Azov–Kuban Basin has shown a positive dynamics. However, it has also been found necessary to increase the scale of artificial reproduction of the most commercially valuable anadromous species: Russian sturgeon Acipenser gueldenstaedtii and stellate sturgeon Acipenser stellatus.

GEOCHEMISTRY AND CARBON ISOTOPE CHARACTERISTICS OF ASSOCIATED GASES FROM OILFIELDS IN THE NW GREATER CAUCASUS, RUSSIA

The NW Greater Caucasus and surrounding areas have a long history of petroleum production dating back to the mid-19th century. However the origin of the oil and gas is still a matter of debate. This paper focusses on a study area to the north of the western Greater Caucasus covering the West and East Kuban Basins and neighbouring structural highs where oil and natural gas occur in reservoir units of Neogene, Paleogene, Cretaceous and Jurassic ages. The study is based on the results of organic geochemical and stable carbon isotope analyses of 21 samples of associated gases from 16 oil fields. The gas samples' compositions were investigated together with the δ13C values of C1 to C5 alkanes. Twenty of the gas samples were of thermogenic origin and one was mixed (thermogenic and secondary microbial). δ13C values for CH4 for all the gas samples varied over a wide range from -62.3 to -30.0 ‰, indicating major variations in the thermal maturity of the respective source rocks. In a previous study, three genetic types of oil were identified in the study area and are referred to here as Types 1, 2 and 3. Gaseous hydrocarbons associated with Type 1 oils were generated by source rocks in the Middle Eocene Kuma Formation and the Oligocene (lower) part of the Maikop Group which are inferred to have been deposited in anoxic, deep-marine conditions. C2–C5 alkanes in gases associated with Type 1 oils have the lowest (most negative) δ13C values of the samples studied, and the lowest iso-butane: n-butane and iso-pentane: n-pentane ratios. These gas samples were recovered from wells in oilfields located in the south and SE of the West Kuban Basin, in the Akhtyrskaya fault zone which extends along the northern flank of the Greater Caucasus foldbelt. Higher δ13C values of C2–C5 alkanes were found in gas samples associated with Type 2 oils which were recovered from wells in the central West Kuban Basin. The associated source rocks are interpreted to have been deposited in weakly oxidizing subaqueous conditions and to contain mainly marine organic matter but with an input of higher land plant material. The precise age and stratigraphic identity of the source rocks is unresolved but they may comprise the Upper Oligocene – Lower Miocene (middle and upper) part of the Maikop Group. In gases associated with Type 3 oils, δ13C values of ethane to pentane are similar to those of gases associated with Type 2 oils. These gases were recovered from wells in oilfields located on the Adygeya Swell which divides the southern East and West Kuban Basins and from the Armavir-Nevinnomyssk Swell to the north. The precise source of these gases and oils is not known but the oils are probably older than Late Cretaceous on account of the absence of oleanane.

Mercury Anomaly in Oligocene–Miocene Maykop Group Sediments (Caucasus Continental Collision Zone): Mercury Hosts, Distribution, and Sources

The Oligocene–Miocene Maykop Group sediments, mainly composed of illite–smectite, store mercury in strongly variable concentrations from 10 to 920 μg/kg. Extremely high Hg levels (98–920 μg/kg) coupled with abnormal mercury-to-total organic carbon (TOC) ratios (Hg/TOC = 109 to 3000 μg/kg/wt%; TOC = 0.2 wt% to 1.2 wt%) were measured in the Middle Maykop marine shales that were deposited in the deepwater Indol–Kuban Basin under anoxic conditions. The Middle Maykop shales contain up to 70% of total mercury in sulfide form. In heavy mineral fractions, abundant Hg-bearing pyrite (with up to 4810 µg/kg Hg in hand-picked concentrates) is accompanied by sporadic cinnabar. Relative to the Middle Maykop sediments, the Upper Maykop shales have much lower Hg concentrations and Hg/TOC ratios: 10 to 63 μg/kg (34 μg/kg on average) and 7.7 to 137 μg/kg/wt% (39 μg/kg/wt% on average), respectively. Mercury sequestration is inferred to occur mostly by binding in sulfide hosts in the Middle Maykop anoxic deep-sea sediments and in organic matter, Fe3+-(oxy)hydroxides, and clay particles in the Upper Maykop shales which were deposited in a more oxygenated environment. Mercury inputs to the marine shales during Maykopian sedimentation were possibly associated with local Oligocene–Lower Miocene volcanic activity in the Caucasus Continental Collision Zone. At the same time, the mode of Hg binding in sediments was controlled by redox conditions which changed from anoxic to disoxic and suboxic at the Middle-to-Upper Maykop transition.

Environmental safety assessment in the influence zone of the existing Zelenchukskaya HPP-PSHS and Krasnogorsk HPP-1, HPP-2 under construction in the area of Ust-Dzhegutinsky reservoir location

«Environmental safety “in the considered spatial limits of the Upper Kuban basin geosystem (F w=11,0*103 km3, W l=3,3*103 km3, Watm=110*103 Wb.g.U.K..=124,3*103 km3) makes up about 21.4% of the spatial limits of the Kuban River, where water resources are formed according to the average long-term data about 3,0 km3, which are used in various sectors of economic activity, including for the electricity generation at Zelenchukskaya HPP-PSHS and Krasnogorsk HPP-1 and HPP-2 under construction with installed power up to 25 mW, located below the HPP-PSHS Zelenchukskaya section and above the alignment (12 km) of the Ust-Dzhegutinsky reservoir. Such HPP-PSHS placement on a 15 km long section of the Kuban Zelenchukskaya riverbed and Krasnogorsk HPP-1 and HPP-2 under construction determined a highly active zone of influence (IV), which is caused by a change in the natural hydrograph of the Kuban River, with the formation of the channel flow movement unsteady hydraulic regime in the considered section of the river to the Ust-Dzhegutinsky reservoir. Unsteady changes in the water level in the Ust-Dzhegutinsky reservoir affects the pressure front structures safety, the functional operation of the water intake system in the Bolshoi Stavropol Canal (BSC) and hydraulic BSC operation. To assess the level of “environmental safety”, it became necessary to develop a mathematical model of the impact of the HPP-PSHS functional work and Krasnogorsk HPP-1 and HPP-2 under construction at the level modes of operation of the Ust-Dzhegutinsky reservoir.

К вопросу о заторах и зажорах в бассейне р. Кубани

Purpose: analysis of quantitative indicators of actual сongestion and ice jams in the Kuban river basin with subsequent intra-basin zoning of the parameters studied. Materials and Methods: data from hydrometeorological observations of ice phenomena were used. The summary calculation of the quantitative indicators of gorges and ice jams along the river Kuban, as well as for each basin of tributaries of the first order was carried out. Results: as a result of the analysis, it was found that the cases of maximum ice jams above the “0” graph in the river Kuban basin were observed more often than the maximum gorge rises. On the river Kuban the number of jams was 90, gorges – 64; in the river Belaya basin number of jamming phenomena was 96, gorges – 9; in the river Laba basin – 43 ice jams and 18 gorges; on the river Pshish the number of jams – 31, gorges – 6; in the river basin Urup the number of jams is 10, and the number of gorges is 20; the river Bolshoi Zelenchuk basin has 25 jams, and 5 gorges. The maximum rise in the water level during jams was 248 cm on the river Pshish at the Bzhedukhovskaya gauging station. The highest water level during gorge events was also recorded on the river Pshish in the aul Teuchezhkhabl and amounted to 386 cm. Most of the recorded cases of water level rise in the presence of gorge phenomena occur at the end of December and the second decade of February. There are no observational series of gorge events at most gauging stations, but, according to available data, most gorge events occur at the end of January and the second decade of February. Conclusions: gorges and ice jams are very dangerous natural phenomena and therefore require promptness and accuracy of forecasting. The solution of such problems is impossible without a network of hydrological posts and observation points, which is currently underdeveloped. Therefore, thickening and improving the existing observational network is one of the main solutions to this issue.

Genetic Types of Crude Oil in the Eastern Part of the Crimea–Caucasus Area

The paper presents data on 48 samples of crude oil and oil shows from oil fields and surface oil seeps in the Krasnodar Territory, Crimea, and the Russian part of the Black Sea. The oil samples were analyzed for isotope and molecular composition. According to the results, all crude oil samples were classified into three genetic types (Akhtyrsky, Sladkovsky, and Nikolaevsky), which differ in molecular and isotope composition and were derived from different types of source organic matter. A source rock was identified only for the Akhtyrsky genetic type (type 1): these were rocks of the Middle Eocene Kuma Formation and the Oligocene rocks of the Lower Maikop Group. The source rock for the Sladkovsky genetic type (type 2) of the oils may have been Lower Miocene rocks of the Middle and Upper Maikop Group, which occur at depths greater than 4000 m in the central part of the West Kuban basin. The source rocks of Nikolaevsky genetic type (type 3) of the oils may have been older rocks, no younger than of Early Cretaceous in age. It is demonstrated that the Cenomanian–Turonian rocks, which are often considered to be among the dominant source rock for oil in this area, most likely could not make any significant contribution to the oil and gas potential because the thicknesses of these rocks are very small, and also because no molecular and isotopic signatures of their organic matter are found in the crude oils and oil shows.

Assessing the Pollution Level in the Kuban River Basin by Multivariate Cluster Analysis

Considering features of hydrological conditions for hydro-chemical system, this paper analyses the performance of the hydro-ecological status of the Kuban river basin.. The results of the study on water chemical composition depending on the distance from the source are presented. By comparing the results with the reference values of water quality, increased aluminium, zinc, and copper content was established. Respective dendrograms of hydro-ecological studies obtained according to performed analysis for the Kuban River and its tributaries are presented. The relevance of the findings received is p<0.0005 and the correlation coefficient corresponds to 0.935...1. The results of multivariate cluster analysis showed that the Kuban basin has an increased content of particular heavy metals such as aluminium, copper, and zinc.

The Southeastern Sindica Frontier: The Raevskoye Fortified Settlement

The expansion of the Bosporan Kingdom (the interior colonization of Bosporus) was caused by the need for commercial grain in the Greek markets of the Mediterranean. The steep rise in the Bosporan rulers’ incomes followed the annexation of Sindica—one of the most fertile lands of the Northern Pontic region, situated in the Lower Kuban basin. This study discusses the history of the vast chora of the Greek Gorhippia in the southeastern fringes of Sindica, focusing on findings from a Bosporan fort—the Raevskoye fortified settlement. We reconstruct the evolution of the anthropogenic landscape of the area over four centuries (Hellenistic and Early Roman period). The chronology is based on a collection of Bosporan coins from the fortified settlement. We analyze the factors due to which the habitation layers of the fortified settlement span a period from the Early Bronze Age to the High Middle Ages. We provide a new topography of the Early Iron Age aboriginal site, along with that of the fortified site existing during the three Bosporan stages. Special attention is paid to the fortification system, arranged in the Hellenistic period. Studies in recent decades have suggested that the fortifications were constructed according to the typical Bosporan technique of adobe-stone architecture. The fortified settlement evolved over a long period as an economic and political center of a large borderland zone between the Greek civilization and the archaic societies of the Caucasian piedmonta peculiar frontier of the classical era.

Pastoral aquaculture in the reservoirs of the Kuban basin

The article provides calculations and recommendations for fisheries development and improvement of fish productivity of reservoirs in the Kuban basin. The taxonomic composition of water biological resources has been studied and the natural bio-production potential of some reservoirs in the South of Russia has been determined. It is proposed for the purpose of pastoral aquaculture to produce directed formation of the ichthyofauna of reservoirs by yearlings Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Ctenopharyngodon idella, and as anaddition Cyprinus carpio, Mylopharyngodon piceus, Liza haematocheila with an individual mass not less than 25-30 g, which will allow rational use of forage resources of aquatic ecosystems.

The role of the silver carp in increase fish productivity and the reducing the level of eutrophication of eutrophication of reservoirs of Kuban basin

AnnotationThe data on the nutrition of silver carp and its role in reducing the level of eutrophication and increasing the fish productivity of the reservoirs of the Kuban basin are given.

Phylogeny, phylogeography and hybridization of Caucasian barbels of the genus Barbus (Actinopterygii, Cyprinidae)

Phylogenetic relationships and phylogeography of six species of Caucasian barbels, the genus Barbus s. str., were studied based on extended geographic coverage and using mtDNA and nDNA markers. Based on 27 species studied, matrilineal phylogeny of the genus Barbus is composed of two clades – (a) West European clade, (b) Central and East European clade. The latter comprises two subclades: (b1) Balkanian subclade, and (b2) Ponto-Caspian one that includes 11 lineages mainly from Black and Caspian Sea drainages. Caucasian barbels are not monophyletic and subdivided for two groups. The Black Sea group encompasses species from tributaries of Black Sea including re-erected B. rionicus and excluding B. kubanicus. The Caspian group includes B. ciscaucasicus, B. cyri (with B. goktschaicus that might be synonymized with B. cyri), B. lacerta from the Tigris-Euphrates basin and B. kubanicus from the Kuban basin. Genetic structure of Black Sea barbels was influenced by glaciation-deglaciation periods accompanying by freshwater phases, periods of migration and colonization of Black Sea tributaries. Intra- and intergeneric hybridization among Caucasian barbines was revealed. In the present study, we report about finding of B. tauricus in the Kuban basin, where only B. kubanicus was thought to inhabit. Hybrids between these species were detected based on both mtDNA and nDNA markers. Remarkably, Kuban population of B. tauricus is distant to closely located conspecific populations and we consider it as relic. We highlight revealing the intergeneric hybridization between evolutionary tetraploid (2n = 100) B. goktschaicus and evolutionary hexaploid (2n = 150) Capoeta sevangi in Lake Sevan.

Oligocene to Neogene paleogeography and depositional environments of the Euxinian part of Paratethys in Crimean – Caucasian junction

Abstract Paleogeography and depositional environments in the zone of junction of the Crimea and the Greater Caucasus, as well as adjacent areas of the West Kuban Basin, the Sea of Azov and the Western Ciscaucasia are described based on the results of drilling works, seismic studies and multidisciplinary research. Paleogeographic maps are compiled for the early Oligocene, middle Miocene (Karaganian and early Sarmatian) and late Miocene (late Maeotian and early Pontian). The maps represented show gradual sediment filling of the deep West Kuban trough during the Maikopian and middle Miocene, and its gradual closure in the Kerch-Taman area. The deep-water connection of this trough with the Black Sea basin through the Sorokin trough had been closed by the mid-Sarmatian. The entire Kerch-Taman region became shallow by the end of the Maeotian. Significant sea level falls occurred at the end of the Tarkhanian and Sarmatian as well as in the middle of the Pontian. Large erosion channels from these times are traced on the geological and seismic profiles of the northern Scythian shelf.

Hybridization of Caucasian barbels of the genus Barbus s. str.

Hybridization of Caucasian barbels of the genus Barbus s. str.

The Toreutics of Colchis in the 5th-4th Centuries BC Local Traditions, Outside Influences, Innovations

AbstractTwo silver vessels: a silver aryballos from the mid-5th century BC burial No. 11/1969 in Vani and a silver goblet from the ritual complex No. 1 of the Ulyap barrow No. 1 in the Kuban basin, dated to the late 5th-early 4th century BC, are discussed. e similarities in details of the vessels and their decoration with those of the silver vessels found in Lydia and the vicinity of Sinope are pointed out. A group of items of toreutics from the 5th-4th centuries BC complexes in Colchis and outside it is singled out: they are decorated with incised animal or mythological images, the bodies of which are covered with vertical rows of horizontal notches. One can not exclude, that this kind of decoration goes back to the images on the Colchian bronze axes and belts of the 8th-6th centuries BC. The characteristic rosette decorating the bottoms of the vessels from Vani, Ulyap and the phiale No. 61 from the Treasure of Akhalgori is analysed; its genesis is discussed going back to the rosettes on the 6th century BC phialai from Iran, Asia Minor and the Balkans. Further the examples of Lydian metalware found in Colchis are discussed, including the phiale with the votive inscription to the temple of Apollo in Phasis found in the later Sarmatian burial in the Kuban basin. Finally, the problem of the 'international Achaemenid style' and the regional school of Achamenid-inspired toreutics is analysed. In general the author comes to the conclusion of the strong influence of toreutics of the Lydian-Ionian school and Anatolia in a broad sense of this term on the local school of toreutics, which emerged in Colchis in the 5th-4th centuries BC.

Celtic motifs in the late classical and Hellenistic toreutics of North Pontic area

The author discussed some find of the IVth-IInd century B.C. jewelry in Kuban basin in South Russia. The find of a gold stamped plaque in shape of a male head, reflecting the typical motif of Early La-Tène art, in a tumulus near stanitsa Ivanovskaya in Kuban basin suggests the penetration of the motifs of Celtic art in distant periphery of antique world in the kingdom of Bosporus already in the IVth century B.C., i.e. before the well known after literary and archaeological sources evidence of the Celtic penetration in North Pontic area. It was due to the fact that since the first half of the IVth century B.C. the Celts were hired as mercenaries, first by the Dionysius I, the king of Syracuse. With the broad use of mercenaries in Greek armies the soldiers, also barbarian, with their own amunition and armaments, may had found their way in distant parts of oikumene. The possibility of the Celts penetration via South Italy seems to be indirectly proved by the complex find at Sergievskaya of the helmet of Etrusco-Italic type and two small “phalerae” with the design, having prototype among the Celtic and South Italian antiquities of the IVth century B.C. It seems also that some other peculiar motifs in the Hellenistic toreutics of Kuban basin (eight-shaped fibulae) also reflect the influence of the IVth-IIIrd century B.C. Celtic art.