Glacial geomorphology of the Notsarula and Chanchakhi river valleys, Georgian Caucasus

ABSTRACT Detailed glacial geomorphological maps are valuable for identifying target sites for palaeoglaciological reconstructions and thus for palaeoclimate inferences. In this study, we present the first detailed glacial geomorphological mapping of the landform assemblages produced by the former glaciers in the Notsarula (42°45′44″N 43°38′29″E) and Chanchakhi (42°42′5″N 43°40′42″E) river valleys, Georgian Caucasus. Our goal is to create a high-resolution (1:33,000 scale) glacial geomorphological map of this area (237 km2) and provide a detailed and accurate distribution of glacier-related features (see Main Map). Several field investigations between 2010 and 2022 along with detailed remote sensing surveys have been conducted for this glacial geomorphological mapping. The mapped landforms indicate multiple readvance or stillstands of valley glaciers across the study area. The largest and complex glacier body likely existed in the Bubistskali River gorge (42°43′16″N 43°43′32″E). Well-preserved moraine landforms in this valley suggest at least five large and several relatively small glacier readvances or stillstands occurred during the Late Quaternary. The simple-valley-type (without branches) glaciers were also probably present in other tributary valleys of the Chanchakhi River basin at that time. This map can be used for further geomorphological investigation as well as to support future geochronological work in the Greater Caucasus.


Introduction
Glacial geomorphological mapping is an essential tool providing a valuable baseline for any further scientific investigation in palaeoglaciological studies (e.g. Lee et al., 2022;Leger et al., 2021;Tielidze et al., 2023a).More specifically it consists of thematic mapping of geomorphological features focusing mainly on reconstructing and documenting accurate glacial and periglacial landforms and processes (Chandler et al., 2018).This approach combines different methods such as field work observations and remote mappingi.e. using remote-sensed data and techniques to perform geomorphological interpretations (e.g.Carrasco et al., 2020;Köse et al., 2021;Tielidze et al., 2021).Although geomorphological mapping has been used for the past 150 years, the practice has grown significantly in recent decades thanks to recent developments in geomatics and the increasing access to high-resolution remote sensing data and software (Chandler et al., 2018;Knight et al., 2011).These resulting glacial geomorphological maps are useful to understand long and short-term landscape evolution and the glacio-climatic drivers responsible for glacial activity.In a present-day context of climate change, glacial geomorphological mapping is also useful for documenting past and modern glaciers' behaviour (debris-free or debris-covered, rock glaciers), paraglacial adjustment and slope dynamics to assess natural hazards in an inhabited and touristic area such as the Greater Caucasus (e.g.Paron & Claessens, 2011).
Well-preserved glacial landforms in the Greater Caucasus suggest that this region hosted extensive Quaternary glaciers (e.g.Gobejishvili et al., 2011), offering a unique opportunity to study Quaternary climatic and environmental changes in this region.Given the location of the Greater Caucasus at the crossroad between south-eastern Europe and southwestern Asia, this type of study can be significant not only at a regional but also at a continental scale, in establishing palaeo-glacial-climatic links between the European Alps and the mountains of Asia.The identification of well-developed glacier-related landforms and detailed glacial geomorphological mapping is one of the first steps forward in this task.Considering that a similar work has not yet been carried out in the Greater Caucasus, there is a clear need to perform high-resolution glacial geomorphological mapping in this region.In this study we create the first detailed glacial geomorphological map from the Greater Caucasus (Racha Region) to support future geochronological work which will help us to better understand past glacier-climate interactions in the Northern Hemisphere.Another purpose of our work is to develop a framework for future glacial geomorphological mapping in the Greater Caucasus region.

Study area
The Greater Caucasus is a complex sub-latitudinal mountain system that stretches about 1150 km between the Black and Caspian seas in a west-northwest to east-southeast orientation.It is a part of the Alpine geosynclinal belt (Gvozdetsky & Golubchikov, 1987).The Greater Caucasus consists of one main watershed range with an average elevation of 3500 m asl., and several sub-ranges of relatively low altitude.It is traditionally subdivided into three partswestern, central and eastern Greater Caucasus, separated by cross-sections passing through Mt Elbrus (5642 m asl) and Mt Kazbegi (5047 m asl) which are two dormant volcanoes of this region (Maruashvili, 1981).
The Greater Caucasus is located at the border of temperate and subtropical climatic zones.It is a barrier for the advance of cold air masses from the north to the south, and warm air masses from the southwest and west to the northeast and east.The climate of the Greater Caucasus is formed mainly under the influence of the subtropical high-pressure belt in summer and the western spur of the Siberian maximum in winter.The average annual air temperatures in the Greater Caucasus are positive up to elevation 2400-2800 m asl.(Panov et al., 2008).As this mountain range is orientated at an angle to the western humid air flows, the distribution of precipitation is uneven.The southern slope of the western Greater Caucasus is the most humid with >2500 mm annual precipitation, while in the east, humidity decreases, and only 400-600 mm of annual precipitation falls on the southern slope of the eastern Greater Caucasus (Volodicheva, 2002).
The study area covers the Notsarula and Chanchakhi river basins, which are located on the southern slopes of the central Greater Caucasus and cover an area of approximately 237 km2 (Figure 1).
Notsarula River basin situated on the southern slopes of the central Greater Caucasus.It covers a relatively small area (∼53 km 2 ) and bordered by the Chveshura River basin from the west and the Chanchakhi River basin from the east.Notsarula is the main river in this basin flowing about 14 km southward from the southern slopes of the central Greater Caucasus.From the east and west, it is surrounded by Molisa Range and one unnamed meridional range.The Kotsantsara River is the largest tributary of the Notsarula River, which joins from the east at an altitude of 1920 m asl.
Chanchakhi River basin encompasses the southern part of the central Greater Caucasus and the northern slopes of the Kedela Range.It is one of the largest river systems in the Rioni River basin, starting from Chanchakhi Glacier and flowing about 22 km southwestward before joining Rioni River at an altitude of 1130 m asl.Bokostskali (∼8.5 km) and Bubistskali (∼9.5 km) rivers are two largest right tributaries of the Chanchakhi River, while the Chkhoshura, Gheske and Khamijou rivers are relatively small tributaries (Figure 1).

Previous work
Studies focused on large-scale topographical mapping in the Caucasus began in the second half of the nineteenth century, mainly for military purposes (Chekurishvili, 1988).These studies were based on plane table surveying, which resulted in many defects in remote areas.In particular, the shape of many of the remote glaciers was mapped incorrectly (e.g.Tielidze, 2016).More accurate topographic surveys of the Caucasus were accomplished several decades later with 1:50,000 scale topographical maps from 1955 to 1960 aerial imagery (e.g.Tielidze & Wheate, 2018).Based on these maps and many early expeditions, several researchers previously investigated the past glaciations and geomorphology of individual parts of the Greater Caucasus (e.g.Gobejishvili et al., 2011;Khazaradze, 2004;Kovalev, 1961;Serebryanyi et al., 1984;Shalnev et al., 2019;Tsereteli, 1966).Despite these efforts, none of these previous scholars produced large-scale glacial geomorphological maps of the Greater Caucasus.

Methods
Glacier-related landforms of the study area have been mapped from remotely sensed imagery using the Environmental Systems Research Institute's (ESRI) online service, such as ArcGIS (ESRI Arc-GIS).A medium-resolution (10 m) Sentinel-2 image from 2020 along with high-resolution (1.5 m) SPOT-7 scene from 2019 and several Digital Globe products (up to 5 m resolution) have been processed to cover the entire study area (Figure 2a).Imagery was captured under cloud-free conditions mainly within July-September when the terrain surfaces were mostly free of seasonal snow.The Sentinel scene was downloaded from EarthExplorer (http://earthexplorer.usgs.gov)(last access: May 2023), while the orthorectified high-resolution SPOT scene was received from Azercosmos (https://azercosmos.az/, last access: April 2023).For 3D visualisation that aided identification of all landform types, high-resolution QuickBird images (2019) superimposed upon the SRTM3 topography (Raup et al., 2014) through to the Google Earth Pro software have also been used (e.g.Tielidze et al., 2021).The geomorphological mapping was also conducted by visual interpretation of large scale (1:50,000) individual georeferenced topographical maps (4 sheets) taken from Tielidze and Wheate (2018).We used the Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) digital elevation model (DEM) with a 12.5-m resolution downloaded from the Alaska Satellite Facility (ASF) Distributed Active Archive Center (DAAC) (https://vertex.daac.asf.alaska.edu)(ASF DAAC, 2015), and was used to generate the contour lines and the hill shade map.
In addition to remote mapping, we conducted four extensive field mapping campaigns in the summer and autumns of 2010, 2012, 2014 and 2022.The approximate size, shape and orientation of glacier-related landforms were documented during the field campaigns, which allowed us to identify features that are not always easily discernible from remote sensing data.
Based on the detailed visual analysis of various satellite imagery and large-scale topographical maps in combination with medium-resolution DEM and several field campaigns, we mapped all glacier-related landforms visible in our study area.The layers were projected in the WGS84 Coordinate Systems (N38) through the ArcGIS software (v10.8.2) and exported into the Adobe Illustrator CS7 as an individual vector layers for editing graphic design and final production (Figure 2b, see also Main Map).

Glacial geomorphology
Eight categories of glacial landforms were identified and mapped on our large-scale (1:33,000) glacial geomorphological map.All landform types were classified and manually digitised as polygon and polyline shapefiles.The mapped landforms include modern glaciers, active and relict rock glaciers, cirques, ice-scoured bedrock, ice-contact slopes, moraine ridges, outwash plains and alluvial fans (see Main Map).In addition to these landforms, our map also includes other landform types such as steep eroded slopes, eroded slopes, active scree slopes, vegetated scree slopes, active river plains, alluvial plains, landslides and gullies.Topographic features such as rivers, peaks, passes, contour lines and fault lines that are useful for topographic and physiographic context are also shown.Our interpretation and identification criteria used for glacial geomorphological mapping are based on recent studies (Bendle et al., 2017;Darvill et al.,   bedrock and moraine ridges, in detail as the most significant and prominent glacier-related features in our study area.

Modern glaciers
According to a recent glacier inventory in 2020 (Tielidze et al., 2022a), there are seven glaciers in the Notsarula River basin with the total area of 3.46 ± 0.17 km 2 .The Kotsantsara Glacier (42°46 ′ 13 ′′ N 43° 41 ′ 36 ′′ E) is the largest in this river basin with an area of 0.88 ± 0.06 km 2 .It is a debris-free cirque glacier of the southwestern aspect.This glacier has very short tongue (∼0.3 km) terminating at an altitude of 3280 m asl.The other two relatively large glaciers in this valley are the northern and southern Notsarula glaciers with the total area of 1.57 ± 0.09 km 2 (see main Map).
There are 16 modern glaciers with the total area of 11.20 ± 0.45 km 2 in the Chanchakhi River basin.Glaciers are found mainly on the southern slopes of the Greater Caucasus in this basin.Although, two small cirque glaciers are also preserved on the northern slopes of the Kedela Range at the headwaters of the Chkhoshura and Khamijou rivers.
The Boko Glacier (42°45 ′ 55 ′′ N 43°42 ′ 51 ′′ E) is the largest glacier in the Chanchakhi River basin.It is a valley glacier with the total area of 4.51 ± 0.18 km 2 that is flowing towards the southwest.This glacier has a wide accumulation area (firn) stretching from the north-west to the south-east for about 4 km.The firn of the Boko Glacier is connected to the Karaugom Plateau of the northern slope, one of the largest ice plateaus in the Greater Caucasus and likely feeds the Boko Glacier.The width of the firn at the place of junction with the Karaugom Plateau is about 1.0 km (based on remote sensing).The approximately 2km-long Boko Glacier tongue is flowing down the valley and terminating at an altitude of 2702 m asl.The surface of the Boko Glacier tongue is free of debris.
The Buba Glacier (42°45 ′ 2 ′′ N 43°44 ′ 52 ′′ E) contains three separate accumulation areas that combine a wide ice tongue (∼1.6 km), which terminates at an altitude of 2995 m asl.It is the second largest glacier in the Chanchakhi River basin with the total area of 3.14 ± 0.12 km 2 .Glacier flows to the southwest and has a debris-covered tongue.The central flow in accumulation area of the Buba Glacier is weakly connected to the Karaugom Plateau of the northern slope the Greater Caucasus.They are likely to be divided in the coming years.Buba Glacier has had the longest series of stationary mass balance observations in Georgia since 1965, which was interrupted in the 1990s (Gigineishvili, 1986;Tielidze et al., 2022b).
The Tbilisia Glacier (42°44 ′ 24 ′′ N 43°46 ′ 26 ′′ E) is the third largest glacier after the Boko and Buba glaciers in the Chanchakhi River basin with the area of 1.80 ± 0.09 km 2 .It is flowing towards the southwest and located at the headwater of the eastern tributary of the Bubistaskali River.The glacier has a very fractured surface and a tongue with a thin cover of debris, terminating at an altitude of 3062 m asl.
A large rock-ice avalanche was released on the Tbilisa Glacier on August 3, 2023, from an altitude of ~3800 m asl.The rock-ice avalanche transformed the downslope into a fast-moving glacial mudflow that was deposited at the Shovi Resort area at an altitude of ~1500 m asl.The most part of the Shovi Resort was completely devastated by the glacial mudflow (Figure 3), resulting in numerous casualties.Thus, the Tbilisa Glacier can be considered a considerable hazard to the society and infrastructure of the Georgian Caucasus, similar to the Devdoraki Glacier, known for its icy avalanches (e.g.Tielidze et al., 2019).

Rock glaciers
Geomorphological evidence such as ridges and furrows, collapse structures, flow structures, lateral margins and steep front, and distinct changes of the slope in the rooting zone are generally used for mapping rock glaciers (e.g.RGIK, 2022; Wagner et al., 2020).Although, identifying of rock glaciers is often challenging, especially distinguishing them from protalus, pronival ramparts and debris-covered glaciers (e.g.Hedding, 2016;Jarman et al., 2013).Latest rock glacier inventory for the Greater Caucasus has been recently completed by Tielidze et al. (2023b) accounting 2 rock glaciers in the Notsarula River valley and 8 rock glaciers in the Chanchakhi River basin with the total area of 1.57 km 2 .Two categories of rock glaciers based on their activity were distinguished according to this inventory: (i) active rock glaciers and (ii) relict rock glaciers.(i) Active rock glaciers have an oversteepened front, with an angle exceeding the angle of repose of the material and signs of ongoing erosional processes.Ridges and furrows, formed as a result of cohesive flow of permafrost creep, are often identified on the surface of active rock glaciers (e.g.Lytkin, 2020).Their surface also consists of large coarse clastic material.(ii) Relict rock glaciers, which are interpreted as an evidence of past permafrost creep, have a much more subdued surface (e.g.Barsch, 1996).Relict rock glaciers are typically found at lower altitudes than active rock glaciers (e.g.Baroni et al., 2004;Scotti et al., 2013) with a less steep front compared to active counterparts.Sometimes they are still conserving distinct furrows and ridges and are recognisable in the landscape even though they often present a vegetated surface.
Six active rock glaciers with the total area of 0.80 km 2 were distinguished in our study site (Figure 4), while the 4 rock glaciers with the total area of 0.77 km 2 identified as relict one.The largest relict rock glaciers with an area of 0.31 km 2 was found on the northern slope of Kedela Range in the headwater of Dgviora River (42° 40 ′ 9 ′′ N 43°38 ′ 25 ′′ E), while the largest active rock glacier with an area of 0.21 km 2 is located on the southern slope of the Greater Caucasus main watershed range, near the Tbilisa Glacier (42°43 ′ 55 ′′ N 43°45 ′ 57 ′′ E).

Cirques
Cirques (corries) are amphitheatre-like valleys formed by glacial erosion.The concave shape of a glacial cirque is open on the downhill side, while the cupped section is generally steep.Cirques often record local cirque glaciation during phases of glacier advance/ retreat (Glasser & Jansson, 2008).Cirques are very common features in the study site as 14 were identified in total, i.e. 4 in the Notsarula River basin and 10 in the Chanchakhi River basin (see Main Map).Most of these cirques are located either on the southern slope of the central Greater Caucasus (south-facing) or on the northern slope of the Kedela Range (north-facing).Eight of the cirques are more than 1 km wide, ranging from 1 to 2.8 km whereas six of them are less than 1 km wide ranging from 400 to 700 m.The south-facing cirques are relatively higher (3500-3400 m asl) and still occupied by modern glaciers, while the north-facing cirques are comparatively lower (2800-3400 m asl) and occupied by both relict rock glacier and very small, degraded glaciers.

Ice-sculpted bedrock
Ice-sculpted bedrock generally marks former areas of relatively thick, fast-flowing and warm-based ice causing efficient subglacial erosion (Leger et al., 2020).Icesculpted bedrocks are apparent/exposed for only five south-facing glaciers' ice margin located on the southern slope of the central Greater Caucasus.Relatively large feature of ice-sculpted bedrock is present at the head of the Notsarula River valley (42° 47 ′ 24 ′′ N 43°39 ′ 58 ′′ E).These types of glacial surface are missing on the northern slope of the Kedela Range.

Moraine ridges
As a result of post-glacial processes, many moraine deposits have been partially eroded and washed away in our study area, although most of these landforms still show a clear morphology both in the Notsarula and Chanchakhi river valleys.Moraine deposits were mainly identified during the field campaigns and using the high-resolution satellite imagery with additional usage of Google Earth Pro software for 3D visualisation.To avoid complexities, we did not classify moraine deposits although the size of these landforms varies from several tens of metres to several kilometres in our study area.Most of the lateral-terminal moraines are well preserved in the Kotsantsara, Bubistskali, Bokostskali river basins and Chanchakhi river headwaters (see Main Map).
Two lateral moraine ridges stretch along the western (right) and eastern (left) sides of the Bokostskali River gorge (42°45 ′ 0 ′′ N 43°41 ′ 43 ′′ E and 42°44 ′ 48 ′′ N 43° 41 ′ 55 ′′ E), making a downward curve and transforming into the terminal moraines demarcating the limit of former glacier margin at an altitude of 2270 m asl.Both moraine ridges have very well-preserved crests, reaching 1.9 (western) and 1.6 (eastern) km in length along the valley.Ice contact slopes of both moraine ridges are sharply inclined, while the ice-distal slopes are only gently inclined and separated from the main valley slopes by small meltwater channels.Due to morphological similarities with other dated moraine features from the Greater Caucasus (e.g.Solomina et al., 2016;Tielidze et al., 2020), we assume that these moraine ridges may have been deposited during the late Holocene or the Little Ice Age (LIA).Several relatively small moraine sequences are situated on the bottom of the valley, between these two moraine ridges.
The largest number of moraine deposits is preserved in the Bubistskali River valley.In particular, at least five well-preserved large moraine landforms are found on the western (right) side of the river valley (Figure 5).This set of five lateral vegetated and rounded moraines are approximately over 200-300 m wide each.These moraine ridges are parallel and oriented in a northsouth to southwest direction.The crest of the outer lateral moraine ridge (moraine 1 in Figure 5) ranges in altitude between 2400 and 2600 m asl (42°43 ′ 33 ′′ N 43°43 ′ 10 ′′ E).The height of the moraine is about 150 m, while its length is about 1.2 km.On the inner eastern (left) side of this moraine, about 60 m downhill, a 700-m-long moraine ridge-2 can be seen (42°43 ′ 32 ′′ N 43°43 ′ 22 ′′ E).The longest (∼2.6 km) lateral-terminal moraine ridge-3 in the Bubistskali River valley (42° 43 ′ 18 ′′ N 43°43 ′ 27 ′′ E) reaches the bottom of the valley determining the lowest limit of the former glacier terminus at an altitude of 1875 m asl and suggesting that the maximum length of the palaeo glacier could have been ∼8 km during the Late Quaternary or during the Last Glacial Maximum (LGM).The next moraine deposit is the ridge-4 with relatively small geometry and reaches only 900 m in length (42°43 ′ 10 ′′ N 43° 43 ′ 19 ′′ E).The surface of moraine ridge-4 is almost entirely covered with forest.This moraine feature is also clearly demarcating the limit of former glacier margin at an altitude of 1955 m asl.The last proximal moraine of this group is Ridge-5, which is about 2.2 km long and about 200 m high (42°43 ′ 34 ′′ N 43°43 ′ 48 ′′ E).The crest of this moraine feature is varying between 2100 and 2550 m asl.These five morainic formations host scarce but rather large flat boulders.
Two large moraine ridges at an elevation of 2300-2600 m asl (42°42 ′ 59 ′′ N 43°45 ′ 6 ′′ E) can be observed on the eastern (left) slope of the Tbilisa River valley (Figure 7), while one moraine landform is situated on the opposite slope of the valley at an elevation of 2550-2650 m asl (42°43 ′ 30 ′′ N 43°44 ′ 45 ′′ E).Several relatively small moraine landforms are also situated on the bottom of the valley.

Discussion
The presented map includes a large number of previously unmapped landforms from the Greater Caucasus.Glacier advances or stillstands are mostly indicated by the positioning of terminal and lateral  moraines.A large number of moraine ridges are preserved in the Bubistskali River valley, while a relatively small number of moraine ridges are observed in almost all tributary river valleys.Based on this, it is evident that most of the valleys in our study area were formerly covered by extensive valley glacier bodies.
Direct comparisons of our map with other studies from the Caucasus are difficult due to the lack of previous data, i.e. none of the earlier works provide a detailed glacial geomorphological mapping for individual river basins, which makes such a comparison hard.However, a regional study that used moraines and glacial stratigraphy to reconstruct past glaciations in the Greater Caucasus (Gobejishvili et al., 2011) suggests that the palaeo Buba-Tbilisa Glacier was merged with former Boko Glacier during the Late Quaternary.They also assumed that the maximum length of this complex palaeo glacier could have been ∼23 km with terminus positioning at an elevation of ∼1100 m asl.Based on our investigation, it is reasonable to assume that glacier extent in the Chanchakhi River valley was much smaller in scale than previously thought (e.g.Gobejishvili et al., 2011) as we have not seen any evidence of more extensive glaciation than we described above, i.e.Buba-Tbilisa complex Glacier could not have been merged with Boko Glacier.The maximum length of the Buba-Tbilisa complex Glacier could only have been ∼8 km during the Late Quaternary with terminus positioning at an elevation of ∼1875 m asl.
The newly created map provides a detailed record of glacial landforms and clearly shows palaeo glacier behaviour during the Late Quaternary.We, therefore, consider the landform record documented throughout the investigated area, is accurate.However, the lack of field investigations of the mapped landforms is one of the main limitations of this study as we have not visited all tributary river valley during the field campaigns.Other limitations of this map are the spatial resolution of the DEM and satellite imagery, e.g. the resolution of the PALSAR DEM (12.5 m) and Sentinel-2 imagery (10 m) is not good enough to accurately map small moraine deposits.However, this was partially compensated using high-resolution SPOT imagery, several Digital Globe products and Google Earth Pro software.In summary, the level of detail and large mapping area coverage demonstrates the adequacy of remote sensing techniques as timeefficient and inexpensive, encouraging the glacial geomorphological mapping of other sites in the Greater Caucasus.

Conclusion
In this study, for the first time we produce the highresolution (1:33,000 scale) comprehensive glacial geomorphological map from the Greater Caucasus covering an area of about 237 km 2 (see Main Map).Medium-and high-resolution satellite imageries, large-scale topographic maps, and DEMs have been interpreted multiple times to achieve cartographic consistency throughout the study area, and to confirm previous field investigations and interpretations.Thus we consider that our map represents an accurate picture of the landforms associated with past glaciations in our study area in the Central Greater Caucasus.The mapped landscape consists of glacier-related landforms that have not been previously recorded.
The specific findings of this study include several key features of glacial geomorphology: i. Although, the surface morphology of the Notsarula and Chanchakhi river valleys has been partially eroded because of post-glacial fluvial processes, the remaining morphology of the most preserved landforms still allows us to understand past glacier behaviour.ii.Well-preserved glacier moraines in our study area confirm extensive ice coverage during the Late Quaternary.The largest ice body flowed down in the Bubistkali River basin with at least five large readvance or stillstand phases over the Late Quaternary period, with at least three subsequent readvance or stillstand after the Late Quaternary.iii.The terminal-lateral moraine ridge-3 in the Bubistskali River valley suggests that the maximum length of the former glacier could have been ∼8 km presumably during the Late Quaternary with terminus positioning at an elevation of ∼1875 m asl.Buba and Tbilisa glaciers were probably merged and represented one complex valley glacier at that time.iv.A pair of well-preserved lateral-terminal moraine ridges in the Bokostskali River gorge suggest at least one glacier readvance or stillstand probably during the late Holocene or LIA.The maximum length of the former glacier could have been ∼6 km during that time with terminus positioning at an elevation of 2270 m asl.Relatively small moraine deposits between these moraine ridges also indicate several subsequent (i.e.post-Holocene or LIA) readvance or stillstand of the former glacier.
Mapped glacial geomorphology will be used in future investigations, including surface exposure dating, aimed at detailed palaeoglaciological reconstruction of past mountain glaciers in the Greater Caucasus.

Software
The satellite imagery and large-scale topographical maps along with the DEM were processed in the Geographic Information System ArcGis® 10.8.2 (ESRI) software.For 3D visualisation and the identification of all landform types, the Google Earth Pro software have also been used.Adobe Illustrator CS7 was used for final production of the map in pdf format.

Figure 1 .
Figure 1.Location of the Notsarula and Chanchakhi river basins.The location of study area relative to the Caucasus region is shown in the inset map at the bottom right.

Figure 4 .
Figure 4. Active rock glacier on the northern slope of the Kedela Range.