Geochemistry,Fluid Inclusions and Sulfur Isotopes of the Goshgarchay Cu-Au Deposit(Western Azerbaijan)in Lesser Caucasus:Implications for the Origins of Ore-forming Fluids

The Goshgarchay Cu-Au deposit is located in the central part of the northwest flank of the Murovdagh region in the Lesser Caucasus.The Goshgarchay Cu-Au deposit is associated with Middle Jurassic volcanic and Late Jurassic-Early Cretaceous high-K calc-alkaline intrusive rocks.The Cu-Au mineralization is commonly related to quartz-sericite-chlorite alteration dominantly composed of chalcopyrite,gold,sphalerite,pyrite,bornite,hematite,covellite,chalcocite,malachite,and azurite.The Goshgarchay copper-gold deposit,which is 600 m wide and approximately 1.2 km long,is seen as a faultcontrolled and vein-,stockwork-and disseminated type deposit.The Goshgarchay Cu-Au deposit predominantly comprises Cu(max.64500 ppm)and Au(max.11.3 ppm),while it comprises relatively less amounts Zn(max.437 ppm),Mo(max.47.5 ppm),Pb(max.134 ppm),and Ag(max.21 ppm).The homogenization temperatures and salinities of fluid inclusions in quartz for stage Ⅰ range from 380℃ to 327℃,and 6.9 wt% to 2.6 wt% NaCl eq.,respectively.Thand salinities in quartz for stage Ⅱ range from 304℃ to 253℃,and 7.6 wt% to 3.2 wt% NaCl eq.,respectively.The calculated δ^(34)S_(h2s)values(-1.5‰ to 5.5‰)of sulfides and especially the narrow range of δ^(34)S_(h2s) values of chalcopyrite and bornite(between -0.07‰ and +0.7‰)indicate that the source of the Goshgarchay Cu-Au mineralization is magmatic.Based on the mineralogical,geochemical,fluid inclusion,and sulfur isotopic data,the Goshgarchay Cu-Au deposit represents a late stage peripheral magmatic-hydrothermal mineralization probably underlain by a concealed porphyry deposit.

Some Aspects of Turkey’s South Caucasus Policy at the Modern Stage

The present work deals with Turkey’s Caucasian policy at the modern stage,from about 2000 to 2020.During this period,the Republic of Turkey has revealed a number of interesting initiatives in the South Caucasus,and we think their study is interesting both in terms of understanding Turkish foreign policy and in analyzing the ongoing processes in the South Caucasus.Since its establishment the Republic of Turkey has been interested in having intensive relations with the countries of the South Caucasus.Consequently,Turkey’s South Caucasus policy is constantly being elaborated by Turkish diplomats,scholars,and analysts.You will find many significant details in the studies or evaluations that are public and available to scientists.These works reveal a great effort of Turkey to successfully develop the South Caucasus policy.We note here that this policy works successfully in many components.We have reviewed the works of all the leading authors who write very interestingly about Turkey’s Caucasus policy.

Continental accretion and incremental deformation in the thermochronologic evolution of the Lesser Caucasus

Apatite fission-track analysis and thermochronologic statistical modeling of Precambrian-Oligocenc plutonic and metamorphic rocks from the Lesser Caucasus resolve two discrete cooling episodes.Cooling occurred during incremental crustal shortening due to obduction and continental accretion along the margins of the northern branch of the Neotethys.(1)The thermochronometric record of a Late Cretaceous(Turonian-Maastrichtian)cooling/exhumation event,coeval to widespread ophiolite obduction,is still present only in a relatively small area of the upper plate of the Amasia-Sevan-Akera(ASA)suture zone,i.e.the suture marking the final closure of the northern Neotethys during the Paleogene.Such area has not been affected by significant later exhumation.(2)Rapid cooling/exhumation occurred in the Early-Middle Miocene in both the lower and upper plates of the ASA suture zone,obscuring previous thermochronologic signatures over most of the study area.Miocene contractional reactivation of the ASA suture zone occurred contemporaneously with the main phase of shortening and exhumation along the Bitlis suture zone marking the closure of the southern branch of the Neotethys and the ensuing ArabiaEurasia collision.Miocene collisional stress from the Bitlis suture zone was transmitted northward across the Anatolian hinterland,which was left relatively undeformed,and focused along preexisting structural discontinuities such as the eastern Pontides and the ASA suture zone.

Tethys Subduction History in Caucasus Region

Caucasus region is located in the center of Alpine-Himalayan orogenic belt. It is made of two Great and Lesser Caucasus fold thrust belts and an intramountain area called Trans caucasus or Mid caucasus. This region contains a system of oceanic crust subduction, island arcs, volcanic arcs, back arc basins and rifts. The earthquakes of 60 km in depth are the evidences of deep brittle zone under Great Caucasus. Without considering Prototethys, Paleotethys and Neotethys Oceans, the tectonic situation of this region is not possible to study. The oceanic lithosphere under oceanic lithosphere subduction made Trans caucasus containing a trans crust. The subduction of Prototethys under Baltic made Great Caucasus and the subduction of Paleotethys under Iran, made Lesser Caucasus. The earth sutures caused by the closure of Prototethys and Paleotethys Oceans are clear in the region. The direction of Paleotethys subduction in lesser Caucasus is a considerable issue. Most of the existing evidences prove the southward direction which is different from Paleotethys subduction in Alborz of Iran. The lithospheric type of Midcaucasus is different from Caspian. Midcaucasus plays the role of determining collision type in the region.

Geochemistry of cryoconite and soils in the Central Caucasus region and its environmental implications

Climate change and deglaciation are active processes in current changing environments.In the Central Caucasus region rapid degradation of glaciers is caused often by the formation of superficial blackcolored sediments-cryoconite.Cryoconite plays a crucial role in changing ecosystems and may contribute to the formation of primary soils after glacier retreat.Over the past 20 years,the frequency of mudflows and other dangerous mountain events have increased in the Central Caucasus,which is associated with the glacial retreats.Intensification of tourism results in increasing of traffic,recreational activity and environment contamination.Determination of the cryoconites geochemical properties in comparison with other types of sediments and local soils is crucial for investigation of geochemistry and contamination state of superficial glacial sediments.This environmental aspect is important in terms of the Central Caucasus settlements safety under conditions of deglaciation and anthropogenic influence.The sediments studied(cryoconite,mudflow,moraine)were sampled at Garabashi and Skhelda glaciers as well as some local soils at the Baksan gorge.Sampled materials were investigated in terms of physicochemical and agrochemical parameters.The concentrations of trace elements(Cu,Pb,Zn,Ni,Cd)were also determined and contamination indices(geoaccumulation index-Igeo,contamination factor-CF and degree of contamination-Cdegree)were used to evaluate the pollution status of studied material.Data obtained shows much higher content of organic carbon in soils(up to 7.82%)in comparison with cryoconite(max.1.63%)due to presence of vegetation,however,the basal respiration values in some cases were similar betweenсryoconite and soils,indicating high rates of microbial activity in a cryoconite holes.It was found that almost all materials studied have sandy structure.Cryoconite sediments on both of the glaciers are enriched with phosphorus,high values of K_(2)O(max.298 mg·kg^(-1))and N-NH4(max.247 mg·kg^(-1))are identified at Garabashi glacier which could be influenced by long-distant transfer but mostly a result of local anthropogenic activity.In case of trace elements,the highest content is identified for Zn(62 mg·kg^(-1) for cryoconite and 60.5 mg·kg^(-1) for soils)and the most contaminated materials are cryoconite from Garabashi glacier and Entisols,up to moderate level,which is mostly associated with local anthropogenic activity.

Migration of organic carbon and trace elements in the system glacier-soil in the Central Caucasus alpine environment

Rapid deglaciation is one of the most important challenges in the Earth science today.One reason of this is specific supraglacial sediments–cryoconites,which represent carbon-containing dust with organomineral matter and living organisms.Investigation of physical and chemical characteristics of cryoconites in the Central Caucasus is necessary in order to understand their influence on alpine territories biogeochemical cycles,pollution and development in conditions of intensive glacial melting and active anthropogenic influence.For this research cryoconites as well as moraines,soil-like bodies and soils have been sampled from the alpine Bezengi Glacier and adjacent Khulamo-Bezengi Gorge.Key physicochemical features(pH values,total organic carbon content,microbial respiration,particle-size distribution)as well as content of trace elements have been defined in sampled materials and several pollution indices(Geoaccumulation index,Contamination factor and Degree of pollution)have been calculated.Results obtained show low values of total organic carbon in cryoconites(max.0.23%)but high values(max.7.54%)in top horizon of soils located in floodplain,indicating its active fluvioglacial transfer which may further accelerate the development of soils.Microbiological activity in the studied soils was mostly influenced by additional input of labile organic carbon from cryoconites with water flows.Particle-size distribution was similar among the studied cryoconites,indicating dominance of sand fraction(up to 85.28%)while studied soils showed higher variability due to influence of weathering.Among the trace elements,cryoconites were mostly polluted by Zn(max.85.70 mg·kg^(-1))which corresponds to high pollution according to pollution indices;Pb(max.24.90 mg·kg^(-1))and Cu(max.17.40 mg·kg^(-1)),up to moderate pollution level.Redistribution of polluted cryoconite material as well as local anthropogenic activities increased pollution of periglacial soils by Zn(max.89.20 mg·kg^(-1)),Pb(max.15.00 mg·kg^(-1))and Cu(max.12.80 mg·kg^(-1)),which was also proven by the pollution indices with up to high level of pollution.

U–Pb LA-ICP-MS geochronology of polygenetic zircons from Beshta and Kamenistaya intrusions(the Greater Caucasus)

The Beshta-Kamenistaya intrusions are located in the Main Range structural zone of the Greater Caucasus.They are composed of tonalitic gneisses that genetically resemble granites of the tholeiitic series of the ophiolitic complexes.The Beshta-Kamenistaya orthogneisses and associated rocks of the nappes differ markedly from those of the Main Range zone.All of them were overthrust to the Main Range zone during the Bretonian orogeny.The age of their protolith and the metamorphism are still not defined.Using the zircon U-Pb LA-ICP-MS dating two age populations of zircons have been distinguished in the rocks of the Beshta-Kamenistaya intrusions.The age of the main population of zircons from orthogneisses is 426-300 Ma.Several age groups can be distinguished in this population.The main group yielded a Concordia age of386.9±1.4 Ma.There are also smaller peaks at 409-405,375-373,and 351 Ma.The oldest ages(426-395 Ma)were detected in the core parts of the complex crystals.We assume that the crystallization of the parental for orthogneisses rocks(tonalities)took place at 410-395 Ma,whereas the Concordia age of 386.9±1.4 Ma and a peak at 375-373 Ma correspond to the metamorphic event.The whole metamorphic cycle,including progressive and regressive stages,occurred between 395 and 370 Ma.Zircons,dated in the Beshta-Kamenistaya intrusion at350 Ma and younger,correspond to the Late Variscan orogeny.Zircons dated 3102-2769 Ma represent xenocrysts captured by the melts during their formation from the ancient rocks in the crystalline basement.

Crustal and uppermost mantle structure of Caucasus and surrounding regions

A 3-D P-wave velocity model is developed for the crust and uppermost mantle of Caucasus and the surrounding area by applying the tomographic method of Zhao et al. using 300 000 high-quality P-wave first arrivals from 43 000 events between 1964 and 2005. This tomographic method can accommodate velocity discontinuities such as the Moho in addition to smooth velocity variations. The spatial resolution is 1°× 1° in the horizontal direction and 10 km in depth. The velocity images of the upper crust correspond well with the surface geology. Beneath the southern Caucasus high velocity anomalies are found in the middle crust and low velocity anomalies are found in the uppermost mantle. Relatively low Pn velocities are located under the Lesser Caucasus, eastern Turkey, and northern Iran. Higher Pn velocities occur under the eastern portion of the Black Sea and the southern Caspian Sea, and also extend into the eastern edge of Azerbaijan. Tomographic model significantly reduces the travel-time residuals.

Glaciers Reduction and Climate Change Impact over the Last One Century in the Mulkhura River Basin, Caucasus Mountains, Georgia

The reduction of glaciers of Mulkhura River basin over the last century is revised in the paper. Mulkhura River basin is located on the southern slope of the central Caucasus from the Mount Bashili (4148 m) to the Mount Gistola (4860 m) and it is the main center of the contemporary glaciations in the Enguri River basin. The percentage reduction of areas of compound valley glaciers with the relation of air temperature and atmospheric precipitation is given in this paper. Also the paper considered the dynamics of the Tviberi and Tsaneriglaciers, which were the Georgia’s largest glaciers at the end of the 19th century. We used the catalog of the glaciers of the southern slope of the Caucasus compiled in 1911 by a well-known researcher of the Caucasus K. Podozerskiy, which was drawn up on the basis of the 19th century maps. In order to identify the area and number of the glaciers of the 60s of the 20th century, we used the work of R. Gobejishvili—the Georgian glaciologist of the 20th-21st centuries, composed on the basis of 1:50,000 scale topographic maps of 1960. The data of 2014 have been obtained by the Landsat aerial images of L8 OLI/TIRS (Operational Land Imager and Thermal Infrared Sensor) taken in August 2014. In the mentioned study, except of the old topographic maps and aerial images, we used the climate information especially air temperature and precipitation data of the Mestia weather station.

Glaciers Fluctuation over the Last Half Century in the Headwaters of the Enguri River, Caucasus Mountains, Georgia

The article considers the variability glaciers parameters of Headwaters of the Enguri River in the years of 1960-1986-2014. The headwaters of The Enguri Riverare located on the southern slope of the Greater Caucasus, in Georgia. Detailed morphologic and morphometric description of glaciers is given. During our research, we used the topographic maps of 1960 and Landsat L5 TM (Thematic Mapper) aerial images, taken in August 1986 and 2014, and the GPS data of 2014. In the mentioned study, except for the old topographic maps and aerial images we used the climate information that we have collected from Mestia weather station (Mestia is the regional center of Zemo Svaneti), which is the only operating weather station in region. Along with the dynamics of glaciers the course of the air temperature has been identified, mainly trends of mean annual and monthly air temperatures for different periods 1961-2013, 1961-1986, 1987-2013 are made. According to them, main reasons for glacier retreat areanalyzed.

Late Pleistocene and Holocene Glacier Extent in the Georgian Caucasus

This article presents the information of the Georgian Caucasus glaciation at the Late Pleistocene and Holocene period (~126,000-11,700 calendar years ago). Our primary aim was to numerically reproduce the ice extent deduced from geological and geomorphological mapping. We used the analog method with the 30 m resolution SRTM DEM (Shuttle Radar Topography Mission Digital Elevation Model). In addition, the rates of glaciation of those times are identified based on the stadial moraines and erratic boulders. The current investigation has revealed that in the Late Pleistocene, the central and western Caucasus characterized the highest glaciation, while the eastern Caucasus boasted the lowest glaciated area, and in the southern Georgia’s highland glaciation has almost the same form as there is in the Eastern Caucasus today. The longest glaciers were located in the Enguri (Nenskra ~36 km, Mulkhura ~35.1 km, Dolra ~34.5 km), Kodori (Sakeni ~25 km, Klichi ~20 km, Marukhi ~17.3 km) Rioni (Buba ~23 km, Kirtisho ~20.5 km, Jejora ~17.5 km) and Tergi (Devdoraki ~38.5 km, Suatisi ~32 km) river basins. We found, that topography thresholds related to the elevation and hypsometry of individual catchments controlled the gradient of the rate of glacier expansion in the domain at that time.

Exploring Turkey’s Strategic Goals in Caucasus Region During the 2020 Nagorno-Karabakh Crisis

After the collapse of the Soviet Union,the lack of a superior power in the Caucasus region has led to regional and international great powers competition.The existing energy resources are the main reason for competitions in the south Caucasus,and besides other crises,the resources have heightened the political tensions among regional and international players.The Karabakh crisis,which has been a regional conflict for many decades,was precipitated in 2020 due to unprecedented armed clashes between Azerbaijan and Armenia,which led to an increase intensions and threats in the Caucasus region.During this time,Turkey,by supporting Azerbaijan,has had a prominent role in determining the results of the conflicts in favor of Azerbaijan.To clarify Turkey’s role in this matter,the present study explored Turkey’s strategic goals in the Caucasus region during the 2020 Nagorno-Karabakh Crisis.Turkey’s strategic goals in this regard have been argued to be geopolitical development,dominance over energy pipelines,and the reinforcement of its position in both the Caucasus region and the international arena.

The dawn and rise of antimony use in the southern Caucasus

Antimony(Sb)was utilised over several millennia as the prime material to opacify or decolour glass and glazes,as well as an accompanying element in copper(Cu)alloys.Metallic antimony objects are rare,and mostly confined to Chalcolithic Central Italy and to the first millennia BCE in the southern Caucasus.The innovation of antimony use in metallurgy seems to be confined to the southern Caucasus,and the invention of it might be even more specifically situated in the Great Caucasus.Preexisting knowledge of mining set the pathway for the initial stage of antimonial copper alloys in the first half of the third millennium BCE and for metallic antimony ornaments in the second half of the third millennium BCE.However,the first major expansion of antimony in the metallurgy of the Racha-Lechkumi district in the southern Caucasus(present-day Georgia)started around 1700 BCE,while its spreading in glassmaking occurred in the Late Bronze Age(LBA).Explanations that place antimony adoption within its broader social context are favoured over those that consider material or geological properties in isolation.A recurring theme is the importance of comparative analysis,both geographically and between the different pyrotechnologies,including the precious metals and glass industries,to explore how social,political,climatic and economic conditions affected adoption and innovation patterns.All these factors are considered to explain why the extraction of antimony blossomed in the Late Bronze Age in the southern Caucasus and to reconstruct a framework of exploitation,distribution/trade and use of antimony in the Caucasus and its neighbouring regions in the south and east.

Chemical geothermometry:application to mud volcanic waters of the Caucasus region

The generation temperatures of gas-water fluids released from mud volcanoes in different provinces of the Caucasian region have been constrained using Mg/Li(T_(Mg/Li))chemical geothermometry.Mud volcanic fluids in the Taman Peninsula(Kerch-Taman mud volcanic province)were generated at temperatures(T_(Mg/Li))from 41℃ to 137℃.The depths of the respective mud reservoirs estimated from T_(Mg/Li) values and local geothermal gradient are in a range of 1.0 to 3.4 km which spans the Maykop Formation of marine shale.For the South Caspian province,the T_(Mg/Li) values of waters vary from 18℃ to 137℃ and the respective root depths HMg/Li of mud volcanoes range from∼0.85 to 6.5 km.The obtained T_(Mg/Li) values for the analyzed mud volcanic waters from Caucasian provinces are in positive correlation with HCO3^(−)contents and water oxygen isotope compositions(δ^(18)OH_(2)O andΔδ^(18)OH_(2)O)and in high negative correlation with Cl^(−).The increase of T_(Mg/Li) toward the Greater Caucasus Range,as well as the lateral T_(Mg/Li) patterns in the Taman and South Caspian mud volcanic provinces,support the idea that mud volcanic fluids generate at temperatures increasing progressively toward the Alpine orogenic belt.

Crisis in the Caucasus

The conflict between Georgia and Russia has global consequences on August 8, as athletes marched into the National Stadium in Beijing to celebrate the Olympic opening ceremony,

A One Century Record of Changes at Nenskra and Nakra River Basins Glaciers, Causasus Mountains, Georgia

The article considers the variability of Nenskra and Nakra River basins glaciers’ parameters in the years of 1911-2014. Nenskra and Nakra River basins are located on the southern slope of the Great Caucasus, between the Kharikhra, Shdavleri and Tsalgmili ranges, in Georgia, in particular in the Enguri River basin. In our research we used the catalogue of the glaciers of Georgia compiled by K. Podozerskiy in 1911. We also used the military topographic maps with the scale of 1:25,000 and 1:50,000 drawn up in 1960 (in former Soviet Union), where there are the glaciers mapped in detail and the ends of their ice tongues on the southern slope of Great Caucasus of those times. We also used the remote sensing method, which is the best modern way for the study of the dynamics of glaciers and this method is remarkable by a quick obtaining of results. The spectral images of the Landsat L8 OLI/TIRS (Operational Land Imager and Thermal Infrared Sensor) (USGS) received from the “Landsat” artificial satellite are the necessary materials for our study. We also used the field survey materials of 2014 (GPS data). The latest statistical information is also given about the glaciers located in the individual river basins;their morphological types, exposition and the dynamics are considered according to the individual years.

The Geosystem Analysis of Exogenesis of High-Mountain Landscapes of the Basin of the River Girdymanchay in Azerbaijan

For the geological systems, assessment of influencing exogenous relief forming processes having essential impact on development of landscape status arises need of development of various field and image interpretation methods for creation of scenarios of possible changes of a geo-ecological situation in various massif having harmful consequences, by identification of relationships of cause and effect. It was analyzed possibilities of prognosis of the changes of the geo-ecological situation in high-mountainous of Great Caucasus with use of the geological, geomorphologic, climate and landscape materials, data of digital processing of the photo images and visual observation. Also the possibilities of forecasting of change of landscape structure of highlands in natural area of Great Caucasus with use of various data were analyzed. It was defined the main differences of relief situation, hydro meteorological conditions in the various parts of high-mountainous geo systems?in which exogenic processes were shown, character and intensity of land using which had the influence to the slope slides. These data allowed revealing the main distinctions of factors of a relief situation?in which were shown exodynamic relief and landscape forming processes, character and intensity of the land use, to some extent influencing on descent of landslides and area of their destructive.

Development of 3-D Gravity-Magnetic Models of the Earth’s Crust of Azerbaijan and Adjacent Areas: an Overview

Azerbaijan is located in the Alpine Himalayan collisional zone and is characterized by its complex and variable geological structure. To study Azerbaijan’s deep structure, twelve main regional interpreting profiles were selected for comprehensive 3D combined gravity-magnetic modeling. The development of the initial physical-geological models (PGMs) was based on known surface geology, drilling data, previous seismic, magnetotelluric and thermal data analysis, examination of the richest petrophysical data, as well as quantitative and qualitative gravity/magnetic data examination. The PGMs thus reflect the key structural-formational specifics of Azerbaijan’s geological structure, beginning from the subsurface (hundreds of meters) up to the Moho discontinuity (40 - 60 km). The PGMs revealed common factors controlling ore- and hydrocarbon bearing formations, primarily the boundaries of tectonic blocks, masked faults, and buried uplifts of magmatic rocks. Many of these factors can be used to investigate long-term geodynamic activity at a depth. The article summarizes many years of investigation by exemplifying the most typical PGMs for the Greater and Lesser Caucasus, the Kura depression, and central and northern Azerbaijan.

Two-step exhumation of Caucasian intraplate rifts:A proxy of sequential plate-margin collisional orogenies

Intraplate structural deformation is diagnostic of tectonic stress regime changes linked to plate interactions and can result from superposed tectonic events whose single contributions are hardly distinguishable.In this paper,we present a set of integrated thermochronologic inverse models along a 140 km-long transect across the central Greater Caucasus and the adjacent Adjara-Trialeti fold-and-thrust belt of Georgia,two intraplate orogens produced by structural inversion of parallel continental rift zones located on the Eurasian plate.Our dataset allows to distinguish discrete and superposed deformation episodes and quantify their respective contributions to orogenic exhumation.The integration of(U-Th)/He analysis on apatite and zircon,fission-track analysis on apatite,and peak-temperature determinations(clay mineralogy,organic matter petrography,Raman spectroscopy)shows that structural inversion was punctuated by two incremental steps starting respectively in the latest Cretaceous and the mid-Miocene.Latest Cretaceous partial inversion of the Greater Caucasus is documented here for the first time and placed in a geographically wider context of coeval deformation.The two episodes of intraplate structural inversion,exhumation,and sediment generation are chronologically and physically correlated with docking of(i)the Anatolide-Tauride-Armenian terrane(Late Cretaceous-Paleocene)and(ii)Arabia(Miocene hard collision)against the southern Eurasian plate margin.Intraplate deformation in the Caucasian domain was triggered by far-field propagation of plate-margin collisional stress which focused preferentially along rheologically weak rift zones.

Evolution of parthenogenetic reproduction in Caucasian rock lizards:A review

Despite numerous works devoted to hybrid origin of parthenogenesis in reptiles,the causes of hybridization between different species,resulting in the origin of parthenogenetic forms,remain uncertain.Recent studies demonstrate that sexual species considered parental to parthenogenetic rock lizards(Darevskia spp.)avoid interspecific mating in the secondary overlap areas.A specific combination of environmental factors during last glaciation period was critical for ectotherms,which led to a change in their distribution and sex ratio.Biased population structure(e.g.,male bias)and limited available distributional range favored the deviation of reproductive behavior when species switched to interspecific mates.To date,at least 7 diploid parthenogenetic species of rock lizards(Darevskia,Lacertidae)originated through interspecific hybridization in the past.The cytogenetic specifics of meiosis,in particular the weak checkpoints of prophase l,may have allowed the formation of hybrid karyotypes in rock lizards.Hybridization and polyploidization are 2 important evolutionary forces in the genus Darevskia.At present,throughout backcrossing between parthenogenetic and parental species,the triploid and tetraploid hybrid individuals appear annually,but no triploid species found among Darevskia spp.on current stage of evolution.The speciation by hybridization with the long-term stage of diploid parthenogenetic species,non-distorted meiosis,together with the high ecological plasticity of Caucasian rock lizards provide us with a new model for considering the pathways and persistence of the evolution of parthenogenesis in vertebrates.