ENGINEERING-GEOLOGICAL FEATURES OF THE TERRRITORY ALONG THE TURKISH-GEORGIAN BORDER

Emil Tsereteli*, N. Gogua*, D. Kalandadze*, T. Lazarashvili*, E. Megrelishvili*, Ali Yılmaz**, Erdal Herece** and Ergun Karacan***

* - Georgian State Department of Geology, 380062, Tbilisi, Georgia. ** - General Directorate of Mineral Research and Exploration, 06520, Ankara, Turkey. *** - C.U. Faculty of Engineering Department of Geological Engineering

ABSTRACT

This part of the study deals with the engineering-geological features of the Turkish- Georgian border area. According to engineering, lithological and genetical characteristics, 6 continental-cover rock formations with 14 geological-genetical complexes and 6 basement rock units with 11 geological-genetical complexes are wholly distinguished. The general characteristics of the formations and geological-genetical complexes, their lithological and petrographical properties and varieties have been presented. There are characteristic wide spectrum of recent geodynamic processes such as landslides, rock- avalanches, erosion and abrasion. In addition, Quaternary glaciation and its fluvio-glacial sediments within the Eastern Pontides and Adjara-Trialeti mountain systems occurred extensively and in the hyposmetricaly lower levels than the setting which was known before. As a result, the schematic engineering-geological map of the region at 1/200 000 scale has been compiled and also the main directions of further engineering-geological investigations are presented.

INTRODUCTION

By the united efforts of the General Directorate of Mineral Research and Exploration (MTA)-Turkey and the Georgian State Department of Geology (SDG), between 1994-1996, the first international project was executed foreseening and conducting joint geological investigations and exchanging existing data, on the example of two adjacent territories. There was foreseen, in this project, compiling of engineering-geological map at 1/200 000 scale (Appendix,6), which should represent the coordinated methods, as a model basis of investigations on the territory of the two countries and possible beyond their borders. Georgian side gave information to their Turkish colleagues about the investigations of engineering geology and dangerous geological processes, forecasting and managing

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problems, carried out in their country, submitted engineering-geological and geodynamic maps at various scales, compiled in Georgia and in the frame of the program in the joint investigations, for the Black Sea Countries. For preparing of mentioned maps, which were used special engineering-geological investigations at 1/200 000, 1/50 000, 1/25 000 and 1/10 000 scale maps used in Georgia for the investigation of special geological studies along the border have been taken as a base for the study in this project. Because of the absence of regional engineering-geological investigations in Turkey, an initial study was carried out between 1995-1996 along the Çoruh River basin and the upper part of the Kura River trough 35 days. The generalization of the engineering- geological map was based on the regional geological map at 1/100 000 scale, jointly prepared by the Turkish and Georgian geologists, and field materials mainly connected to geodynamic and Quaternary sediments. For the engineering-geological characteristics of the rocks were used their physical-mechanical characteristics, presented in Georgia, which give us possibility, by the analogue method, spreading of stratigraphical-lithological properties of complexes with same stratigraphical-lithological properties along the territory of Turkey. So, the analysis, generalization of the existed materials and conducted field works provided a possibility to compile a generalized engineering-geological map of the Turkish-Georgian border-line. Shortage of field materials in the territory of Turkey and absence of geotectonic data from rocks units made the map to be more like a schematic map.

GENERAL ENGINEERING - GEOLOGICAL PROPERTIES OF THE ROCKS

The study of qualitative nature and engineering-geological peculiarities of building rocks, the establishment of regularity of its physical-mechanical properties spatial changes, are the main fundamental estimations of the territories, used in engineering-economic purposes. Stability of the slopes and nature of the development of the dangerous geological process development, scale, reliability of the location of engineering buildings and totally, organize management of the territory, depend on their properties. Here with, the study on of properties and peculiarities of rocks need long time. The properties change from diagenesis to hypergenesis, in continual interaction with natural and tectogenic environment, estimation of their main characteristics. The limits of the geological environment zones, which built the extreme upper part of the geological section of the lithosphere are given and determined as a multicomponent dynamic system of the human's activity. Spatial characteristics of the engineering-geological properties of rock units, are given according to engineering-geological formations, in conditions of special geotectonical and paleogeographical regime from their properties and peculiarities.

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The 12 engineering-geological formations are distinguished in the corresponding complexes, according to lithological and genetical signs, in the studied territory. These formations are; (1) basement rocks: terrigenous, flysch, volcanogenic sediments, carbonates, contact-metamorphic and magmatic rocks; (2) continental cover: coastal-delta, river ravines, slopes, close depressions, and mountain glaciation. At first, the engineering-geological characteristics of the basement rocks, were determined in high mountains. Characteristics of all continental cover depend on petrological composition, stability of the basement rocks and the intensity of exodynamic processes.

Formations involded by the basement rocks

Terrigenous formation Terrigenous formation is represented by geological-genetical complex of the Upper Eocene-Oligocene clayey-sandstone suite. It has wide spread cover on the Eastern part of Akhaltsikhe depression, in Aspindza region, Şavşat and heads of the Potskhovi River. In Şavşat, these sediments have extensive coverage around the Tepeköy, Usluca, Sarıca, Atalar, Çoraklı, Kutlugün, Pınarlı, Meydan, Kocabey and Kirazlı Villages. Hypsometrically these sediments are developed on 700-800 m height, at the bottom of the Şartuldere River ravine and at 2600 m height, in pre-ridge part of Arsiani range. At the heads of the Potskhovi (Posof) river, rocks of this complex crop out in small areas in erosional windows of Goderdzi formations, around the Beykent, Kolköy, Kaleönü and Aşıkzülali Villages. The rocks of the complex, are represented clays, marls, argillites, clays with gypsum, sandstones and conglomerates. Clays and marly clays are the major units. Their thickness ranges from 5 - 10 cm to 0.5 -1 m as a separate layer, and create 80 - 100 m. thick benches. Clays are light blue-grey and dark grey, mainly pelitic, rarely sandy and carbonaceous. They are characterized by bedding and containing of fish scales. The main characteristics of the clays are: natural water content 7.2 – 34.8 %, dry unit weight 1.27 – 1.7 g/cm3, wet unit weight 1.67 – 2.0 g /cm3, specific weight 2.67 – 2.77 and porosity 29.4 – 50.5 %. Quantity of clay grains is 52 – 74 %, within colloidic part (< 0.001 mm) 40 – 45 %. Angle of internal friction 12 - 250, cohesion 0.043 – 0.14 MPa. After saturation (last natural water content 40–50 %), the angle of internal friction decreases from 80 to 120 and cohesion from 0.045 MPa to 0.015 MPa. Modulus of elastisity is 5.0 kg/cm2 in case of loading between 38 - 62, coefficient of porosity 0.7-1.38, after loading 0.62 - 0.82. The some index and mechanical properties of the terrigenous formation are given Table, 1 according to Tsagurishvili (1979). Clays turn into argilite-like rocks in some places according to degree of lithification. Also they include rarelly gypsum minerals.

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On the surface, clays are fractured and weathered. Fractures are different in size and direction. Usualy, they are directed along or across the bedding, because of this, clays disintegrate into thin sheets and plates, which are dusted by the yellow Iarosite and there are well noticed spots of iron oxide. In zone of weathering clays become brown-yellowish colour and keep habitus of Maicopian clays. Thickness of the crust of weathering reaches 10-20 m, rarely 20-25 m. Marls are developed rarely than clays. In normal conditions marls are light blue-grey and bedded. Thickness of the beds is 0,05-0,4 m, in some places, it formes 10-15 m thick benches. Marls often contain sand, fish scales and planty fragments. Marls weather very fast and change from yellowish-grey to yellow color on the surfaces. Characterized by shily sheeting or disintegration into thin plates, they create medium and fine detrital road material. Sandstones are mostly coarse and medium grained, in places, contain medium inter-layers of fine conglomerates, and represented by the quartzic and quartz-feldsparic composition. They are dark grey, characterized by medium and thick bedding. Thickness of separate layers is 0,1-1,0 m, benches - 20-25 m. Sandstones are weathered and fractured on the surface, separated into 0,25-1 cubic meters volume boulders. Fractures often are open or rarely filled by the alluvial clay. In weathering zone, coarse grained varieties are almost in loose condition (sand, road material). Sharp decrease also marks the strongness. The strength limit of the weathered sandstones are 5.5 – 8.6 MPa. Conglomerates are common only in sandstones, in the face of interbeds. Usually they are usually well rounded fine roundstones and shingle, presented by the limestone, tuffites and lavas. Cement is consist of the white colored tuff ash or quarztic sand with clay admixture. Thickness of the separate benches is not more then 4-6 m. All of the rocks are very weathered and altereded. On the surfaces sands and pebbly sands, created by sandstones and conglomerates, are easily washed out by the groundwater. Thickness of the weathering crust, established on the clays, marly clays and marls, change from 3-5 to 20 m. There are usually weathering zones, which make the thickest, wholly argillitizated, montmorillonite-hydromicaceous fine-dispersional zone, located on the top. With changes of composition, strength and stability effect the properties in a dramatic way. Landslides, connected with this complex in Turkey, in limits of the Şartuldere River basin, around Pınarlı, Meydan, Cevizli and Veliköy Villages are characterized with their extensive spreading. There are relatively similar conditions in the Potskhovi River ravine. Degree of the water saturation of the terrigenous formation rocks is low. Underground waters are developed sporadicly and are mainly connected with the fractured sandstones and conglomerates. Clays are practically water-resisting, except upper weathered zone, to the 8-10 m. depth. Discharge of springs is low and rarely reaches 0,1- 0,31 l /sec. Waters are hydrocarbonaceous sulphatic-potasium-sodic character. Total mineralization is 0,2-4,4 gr /l. Most of the waters hawe with acidic and sulphatic characters.

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Table, 1. The some index and mechanical properties of the terrigenous formation (Tsagurishvili, 1979).

Unit Water Poro- Coeff. Coeff. Name of Volume absorbtion sity Limits of the strength (MPa) of of weight according frost- Froste to weight resist ning Rocks (g /cm3) (%) (%) in dry in water after condition satur.cond freeze . Sandstones 2.32- 1.79-8.81 4.44- 28.1-84.3 24.3-78.5 21.5- 0.8- 0.56- (Akhaltsikhe) 2.50 21.0 74.6 0.96 0.96 Sandstones 2.23- 3.65-6.63 8.7- 88.2- 27.5-117.7 23.9- 0.76- 0.53- (Aspindza) 2.44 14.82 135.7 88.6 0.95 0.84 Marls 1.93- 0.89-12 2.18- 25-30 15.1-20.7 -- -- 0.61- 2.45 4.2 0.66 Quartzic- 2.35- 0.26-3.45 52.1- 49.1-133.1 23.2- 0.46- 0.72- feldsparic 2.80 -- 143.2 141.0 1.0 0.97 sandstones

Flysch formation The flysch formation is represented by Paleocene-Lower Eocene terrigenous- carbonaceous complex of rocks, which have relatively exposed in limited area on the west part of study area in Turkey. This formation exposes along the surface in state of narrow stripes and everywhere between Cretaceous and Middle Eocene volcanogenic suites. Rocks of this complex are observed from mountains of Cihadağ and Balıklı in the bottom of the Northern slope of the Arsiani range, in ravines of the Murgul dere, Cihala çay, Chorokhi, Karçal dere, Meydancık dere and Şartul dere rivers. The complex is represented by the rythmic alternation of marls, argillites, lutites, clays, marly limestones and sandstones. Marls, argillites and sandstones are the most widespread. The rest varieties are in the subordinated conditions. Sensitive loams are blueish grey and dark grey colored. Under the influence of weathering agents, they turn into yellowish-grey or brownish-grey, with spots of ferrum oxide. Rocks are thin (0,1 m) and medium layered (0.4-0.8 m) with platy texture. In the mass, they create rhythms with small (0.8-1.5 m) and big (3-3.5 m) thickness. Argillites are less then marls, but they create the main part of the profile. Argillites are also characterized by changes of hardness at the relatively high limits, which is caused by material composition and by textural-structural peculiarities. Percentace of sandstones in the profile is 20 - 25 %. They are mainly in the state of 0.3-0.5 m thick separate layers and small benches. In sensible condition they are yellowish-grey or dark grey. They are thin, medium and rarely thick-layered, thin and medium grained,very rarely coarse grained. Sandstones are grey. After weathering, they become yellowish and easily breaking. Their coarse grained varieties often turn into quartzic-feldsparic sands. Because of weathering, sandstones are fractured mainly perpendicular to the bedding. The joints are 406

dividing the rocks mainly in cubic or prizmatic shape blocks. Volume of blocks is 0.6-1.0 m3. The depth of joints in massif rocks is 10 -12 m. In some places, movement of separate layers along the faults with 0.4 -1.1 m amplitude are observed. Clays, in normal condition, are grey and mottled, hard or medium compacness, rarely carbonaceous with conchoidal fracture bedded. Thickness of separate layers vary from 0.05 to 0.1 m. and of separate benches 0.4 - 0.7 m. Clays on the surface are easily weathered. At first, they create leaflets, then thin lamellate road material, which fastly turn into the clayey mass without shape. These complex rocks are connected with landslidic and erosional processes, especially should be marked by the existance of olistrostromes in the sediments, which are well fixed on the vertical precipice of Hopa-Borchkha road, near the Ciha dağ pass, northward of Koyuncular village, together with tectonically disturbed zones, the places of olistrostromes spread, are the weakest areas in the massif, where there is ability of development of recent geodynamic processes. Water content of this complex is low. The underground waters of shallow circulation are connected with crust of weathering and with tectonically disturbed zones. Discharge of springs is 0.05–0.1 l/sec. According to the chemical composition they are hydrocarbonaceous, sulphatic, calcic-sodic, mineralization is 0.4–0.6 g/l. Type of circulation is fractured, without pressure. The recharge of underground waters is going only by infiltration of atmospheric precipitations. The some index and mechanical properties of the flysch formation are given Table, 2.

Table, 2. The some index and mechanical properties of the flysch formation (Tsagurishvili, 1979).

Unit Water Poro- Limit of the strength (MPa) Coeff. Coeff. of Name of volume absorbtion sity of frostening rocks weight according frost- to weight. resist. (g /cm3) (%) (%) in dry in water After condition satur.cond freeze Clayey 1.78-2.25 0.91-5.15 3.5-9.8 9.5-41.2 9.2-32.2 -- -- 0.61 marls Marls 1.95-2.31 1.07-3.64 2.79- 4.52- 41.3-86.5 -- -- 0.60 4.20 103.5 Argillites 1.67-2.14 -- 8.12- 2.5-12.7 ------23.5 Sandstones 2.41-2.69 0.43-3.70 -- 67.2- 37.2-135.3 60.7- 0.76- 0.52-0.93 153.2 113.2 0.97

Volcanogenic-sedimentary formation Almost half of the studied territoty is consist of by the rocks of this formation. They are widely exposed within Turkey and Georgia, from the Black Sea coast to the Javakheti 407

plateau. Formation is composed of 4 different complexes. These are: geological-genetical complex of Upper Cretaceous volcanogenic suite; lower layered tuffogene suite of Middle Eocene; Middle Eocene medium and upper levels of massive lava tuffogenes and Upper Eocene volcanogenic-terrigenous suite. The geological-genetical complex of Upper Cretaceous volcanogenic suite exposes widely on the west part of the studied territory, mainly along the boundaries of Turkey. These rocks are seen around Selim and Balıklı mountains, the wide watershed of the Chorokhi and Murgul dere rivers, along east, south and west slopes of Karçal range, interfluve of the Karçal dere and Meydancık dere rivers. The east border of the complex extends along the connecting line between the Şolsu, Dutlu, Bahçekapı and Üzümlü villages. In Georgia the local outcrops of analogous rocks are in the canyon-like ravine of the Kura river, between Khertvisi and Tmogvi villages and on the north edge of Javakheti mountains. Lithologically, complex is represented by tuffs, tuff-breccias, tuff-sandstones, lava covers with lenses of limestones and marls, with basal conglomerates at the bottom of the suite. The breccias are coarse detrital. Cement is volcanic ash and tuff material, which are changing by secondary clayey minerals in the weathering zone. In parallel to that, is going disintegration of detrital material, with relatively less intensity. Because of chloritization and pelitization, tuff breccias turn into the clayey mass. According to the data of hardness, the tuff-breccias are hard rocks with medium hardness. Some varieties have low hardness and compliant character towards weathering. Limit of their hardness should not be more then 10.0-15.0 MPa. The weathered tuff- breccias create the clayey and clayey-road superficial cover rock with thickness varying from 5-10 to 20 m. They are easily influenced by landslides and erosion. Tuffs, tuff-sandstones and lava covers are distinguished by their hardness and they belong to the hard and half hard rock groups. All lithological varieties of the complex are very fractured by the tectonic and weathering joints. Most of main rock fractures are developed perpendicularly, because of that, the mass is divided on separate blocks and different road material. In the areas of the powerfull superficial rock coverings, after creation of suitable geomorphological and hydrogeological conditions, landslidic processes are developed in wide scale. Except climatic landslides, with Cretaceous tuffogenous suites are connected many seismotectogenous landslides near Murgul, Zorlu, Meydancık, Obaköy, Dutlu, Seval, Üzümlü and Bağlıca. There is a widespread areal and linear erosion on the slope and peripherial parts of leveled-off surfaces. Water content of the complex is stipulated by a large areal spreading and good reservoir properties. The flooding of the complex is areal. According to the circulation, we have layered-jointy waters. Waters are mainly hydrocarbonaceous sulphatic-sodic,with total mineralization 0.2-0.8 g /l. The recharge of underground water goes by atmospheric

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precipitations. The some index and mechanical properties of the geological-genetical complex rocks of Upper Cretaceous volcanogenic suite are given Table, 3.

Table, 3. The some index and mechanical properties of the geological-genetical complex rocks of Upper Cretaceous volcanogenic suite (Labartkava, 1969).

Water Coeff. Unit absorbtion Poro- Limit of the strength (MPa) of Coeff. of Name of volume according sity frost- frostening weight to weight. resist.

Rocks (g /cm3) (%) (%) in dry in water after condition saturation freeze condition Tuffbreccias 1.99-2.60 1.71-9.33 -- 30-116.1 20.4-90.0 14.7- 0.72- 0.41-0.9 23.9 0.89 Tuffs 2.24-2.46 4.89-5.91 -- 50-123.5 73.0-89.4 42.9- 0.58- 0.6-0.74 57.4 0.79 Tuff 2.35 4.25 -- 54-120 26.4- 19.6 0.74 0.49-0.98 sandstones 118.0 Lava covers 2.54-2.80 0.41-0.51 -- 110-220 134.5- 113.4- 0.54- 0.92-0.98 151.3 117.1 0.87

Geological-genetical complex of Middle Eocene lower layered tuffogenous suite is widely exposed in Turkey, in the western part of the studied territory. On the surface rocks of this complex are continuously outcropped from the Black Sea coast to the Karçal range. From east to north they reach the Meydancık village, then they are cut by the Şartul dere ravine and are terminated at the southern edge of the engineering-geological map. In Georgia, this rocks create small windows in Adjara, on the southern slopes of the Meskheti range and pass along the northern periphery of the Javakheti plateau, as a narrow stripe. Lithologically, complex is represented by alternation of thin and medium layered tuffs and tuff-sandstones, rarely by interbeds of sandstones, marls and argillites, and by andesitic covers. Within the weathering zone, all bedded rocks mentioned above are easily weathered and disintegrated into small, thin and flat road material and coarse grained sand. The product of weathering of argillites, is the lamellar and tabular road material-gravel mass, which turns into the loams very rapidly. Because all of these lithological varieties are almost together, totaly they create road materiallic-gravely grounds with loamy filler. Their crusts of weathering are charcterized by thin-dispersional zone with 1-1.5 m thickness, which is represented by yellowish-brown and brown loams, with inclusions of thin gravel. Also there is 0.8-1.2 m thick, road material zone, with alluvial clayey mass between distructed fragments, and 5-6 m thick boulder zone with light or hidden fractures. Tuff-breccias and tuff-conglomerates create massive and massive layered varieties, which are observed on the current relief as sharp steep slopes and rapids. 409

It is necessary to mark that within the zone of this complex, rocks create a monocline unit with north directed layers. Within the intrusive and tectonically disintegrated zones, rocks are often dislocated and fractured. Angles of gradient are sharply increasing. In such zones the solidity of the massif is abolished and weaked. Thickness of the cover rocks is increasing and composition is changing, in parallel increasing the risk of occur- development of recent geodynamic processes. For example, slopes of the Aralık dere and Deviskel dere river ravines, where the termination of existing equilibrium (cutting down of woods, cut off of slopes, their intensive assimilation e.t.c.) can cause widespread gravitational processes. Within the area, gravitational and erosional dynamics are the most common geodynamic processes. Covering rocks are mostly connected with consistencial landslides, superficial washing out and forming of gourges. The road material zone of the crust of weathering are connected with taluses; and boulder and hidden fractured zone with rock falls of small and medium volumes. Rocks of the complex are distinguished by high and medium water-content, which is stipulated by jointing of rocks, by their areal spreading in the high mountainous zone, where mainly forms the main part of underground waters of the complex and by the climatic condition of the region. The flooding is areal. Circulation type is fracture controlled. The underground waters are hydrocarbonaceous sulphatic-sodic or sulphatic-sodic-calcic, with total mineralization 0.1-0.2 g /l. It is fresh and ultrafresh and not aggressive toward the cement. The discharge of underground waters is decreasing by atmospheric precipitation and condensation.

The geological-genetical complex of Middle Eocene medium and upper massive lava suite has wide spreading on the studied territory, within Georgia and Turkey. Rocks of this complex in Georgia build the Meskheti range, north and south-east peripheries of Akhaktsikhe depression, the interfluve of Potskhovi, Kura and Borjomi rivers. Within Turkey these rocks build Şavşat range, ravine of the Gomçal dere and Upper part of Meydancık dere rivers. These rocks are outcropped in Şavşat, around Ilıca, Gündoğdu, Yoğurtlu, Cevizli, Veliköy, Kami, Ciritdüzü villages and Şavşat town. The complex is mainly represented by massive and thick-layered lava breccias, lava covers and tuffs. The some index and mechanical properties of the geological-genetical complex rocks of Middle Eocene lower layered tuffogenous suite are given Table, 4.

Table, 4. The some index and mechanical properties of the geological-genetical complex rocks of Middle Eocene lower layered tuffogenous suite (Labartkava, 1969; Tsagurishvili, 1979).

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Water Unit absorbtion Poro- Coeff. Coeff. of Name of volume according sity Limits of the strength (MPa) of frostening weight to weight. frost- resist. rocks (g /cm3) (%) (%) in dry in water after condition saturated freeze condition Psammitic tuff 2.64 1.54 -- 5.67 53.4 43.3 0.81 0.94 Pelitic tuff 2.46 4.37 -- 52.2 43.1 28.4 0.79 0.83 Aleurolitic tuff 2.16- 4.64-14.62 1.87- 61.7-93.4 43.0-49.4 47.8 0.96 0.46 2.48 6.77 Tuff-sandstone 2.63 1.92 -- 72.8 64.1 57.4 0.90 0.88 Coarse detrital 2.62 3.22 1.23 108.3 104.6 100.6 0.96 0.96 tuff-sandstone Fine detrital 2.42 7.99 3.30 52.4 44.4 39.6 0.84 0.89 tuff-breccia Weathered 2.17- 4.06-21.26 1.87- dis tuff-breccia 2.43 8.75 integrate Massive 2.58 2.62 -- 128.0 115.4 93.5 0.81 0.90 tuff-breccia Andesite 2.52- 1.32-4.10 0.52- 102.0- 85.0- 83.0- 0.93- 0.81-0.96 2.75 1.61 164.5 156.7 95.0 0.97 Porous 1.95- 14.91- 7.0- 30.8-48.0 23.6-44.0 23.3- 0.7- 0.76-0.92 andesite 2.13 19.44 9.97 34.0 0.99 weakly weathered

All of petrographical varieties mentioned above are hard, solid, stable and they belong to the hard rock group. The tuffs have relatively less characteristic hardness. All of petrographical varieties on the surface are weathered and fractured. Thickness of the crust of weathering is 2-5 m and in the lateritic weathering and hydrothermally changed zones it varies from 30 to 40 m. Rocks of the complex include underground waters. Their ability of water-bearing depends on the jointing of rocks, on hypsometric location and atmospheric precipititions. The underground waters, which are mainly created in high mountainous zone, have first relaxation within the flat surface, and the last, at the bottom of slopes. Created underground water flows, on their way, make sharply expressed hydrodynamic pressure on the covering rocks, together with other factors assists the development of landslides and other gravitational processes. The underground waters mainly characterized by areal spreading and according to the circulation, they are of fractured type. The waters fresh and ultrafresh have low mineralization. According to the chemical composition, they are carbonaceous chloridic-sodic and calcic-magnesium waters. The covering rocks, which are formed on the top of the complex, mainly generate landslides. Boulder zones of the weathering crust, which outcropes on the surface, are connected the different volume rockfalls, and the road material zone are connected to the development of taluses. Taluses and areas of accumulated gravitational detrital material start forming of water-rock mudflows.

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The some index and mechanical properties of the geological-genetical complex rocks of Middle Eocene lower layered tuffogenous suite geological-genetical complex are given Table, 5.

Table, 5. The some index and mechanical properties of the geological-genetical complex rocks of Middle Eocene and upper massive lava suites (Labartkava, 1969).

Water Unit absorbtion Poro- Coeff. Coeff. of Name of volume according sity Limits of the strength (MPa) of frostening weight to weight. frost- resist. rocks (g /cm3) (%) (%) İn dry in water after condition saturated freeze condition. Andesitic 2.61- 0.4-1.81 -- 72.4- 52.2-124.2 51.3- 0.75- 0.70-0.79 porphirite 2.73 179.3 93.9 0.98 The same 2.31- 1.83-4.04 -- 35.5-78.3 15.5-67.2 13.5- 0.87 0.44-0.86 weathered 2.62 58.6 Andesite 2.70 0.19 -- 275.4 256.1 248.6 0.97 0.93 Lava breccia 2.69- 0.37-0.61 -- 80-222.8 58.1-195.1 190.6 0.98 0.73-0.90 2.82 Changed 2.54- 3.53 -- 73.9- 28.9 -- -- 0.39 lava breccia 2.80 170.2

The geological-genetic complex of the Upper Eocene volcanogenic- terrigenous suite is widely exposed and envelopes the basins of Adjaristskali, Kvabliani rivers and Keda-Adigeni line in Georgia. Lithological complex is mainly composed of tuffs, tuffsandstones, clays and clayey marls. The rocks of this complex, in the vertical section and along the direction of spreading are lithologically stable, similar and almost the same as well. In the sensible condition, all of tuffogenous rocks are hard and stable. According to hardness, they belong to the hard and half-hard rock groups, and clays to the united rock group (Table, 5). The quantitative characteristic of clays is gradually increasing toward the Akhaltsikhe depression. In Adigeni region, it equalizes with tuff sandstones and sandstones. Clays and sandy clays are dark and characterized by thin, platy bedding. From the exposing profile of the weathering crust of this complex fall out the road material horizon is very thin. But the thin-dispersional zone is well developed and has the maximum thickness 2-5 m. at the steep slopes and within flat surfaces. The boulder and hidden fractured zones have thickness more than 20-30 m. Within this exposed complex, the hydrogeological conditions are almost the same as in the zone of Middle Eocene medium massive lava complex. But, in the development of landslidic processes, hydrogeological factor is expressed much sharper. Also, it shows 412

nonhomogenous flooding. Watercontent of hard and half hard tuffogenes are high in Adjara. Eastwards, near Adigeni, watercontent is low. According to the type of circulation, it is porous and jointy. Underground waters which are fresh and ultrafresh, are not aggressive towards the cement.

The some index and mechanical properties of the geological-genetical complex rocks of Upper Eocene volcanogenic-terrigenous suite are given Table, 6.

Table, 6. The some index and mechanical properties of the geological-genetical complex rocks of Upper Eocene volcanogenic-terrigenous suite (Tsagurishvili, 1979).

Water Unit absorbtion Poro- Coeff. of Coeff. of Name of volume according sity Limits of the strength (MPa) frost- frostening weight to weight. resist.

rocks (g /cm3) (%) (%) in dry in water after condition saturated freeze condition. Tuffbreccia 2.58 2.26 -- 86.1 79.9 50.8 0.75 0.92 Tuff-sandstone 2.61 1.64 -- 75.7 59.8 -- -- 0.94 Thin-layered 2.27 7.52 -- 59.8 40.3 -- -- 0.69 tuff

Carbonaceous formation The carbonaceous formation is presented by only geological-genetical complex of Senonian carbonaceous rocks. The rocks in this complex are observed in the limited area between Paleocene-Lower Eocene flysch and Lower Cretaceous volcanogenic suites, in spite of narrow interrupted stripes in the Turkish territory. Because of small coverage of rock outcropings, this formation was not shown on the engineering-geological map. The outcroppings of this rocks (10-20 km ) are observed in the heads of the Cihala river, near the Koyuncular and Ciftepinar villages, on the right tributaries of the Şartul dere river, within Bayram and Eskikale villages and in the Eastern part of Karçal range, southwards Çengeli village on the western part of the border in Turkey. The outcroppings of this rocks are in the bottom of the Kura river canyon-like ravine, between Tmogvi and Khertvisi villages, also on the Artvin-Bolnisi block in the Tetritskaro region in Georgian side. The complex is mainly presented by limestones, rarely by marls and dolomites. Limestones are intensively fractured on the surface. In most cases they usually have wide open joints. Some of them are filled by calcite or clayey material. Here are presented the tectonic and weathering joints. On the right slope of the Meydancık dere ravine, between Erikli and Timuoğlu villages, are observed the karst traces. Their directions coincide with bedding planes. According to the intensity of karstic phenomenons, there are weak and medium intensity karstic emptiness. According to the degree and intensity of weathering, the rocks of this complex are different. Sandy limestones and pelitomorphic limestones are distinguished by stability toward weathering agents. 413

Marls and marly limestones are easily weathered and create platy road material and fragments, from 2-5 cm to 12-15 cm. At the suitable geomorphological conditions, the complete weathering is developed on the limestones. The fine-dispersion zone, which is represented by black-brown loams, lie in 0,5-0,8 m depths and at 1,0-1,5 m depths, are the road material zone of the weathering crust. The boulder zone lies at the depth of 8-10 m.. The latter have the trace of karstic developments. With spreading rock complex are connected with the taluses (their development is the latest stage). Separate boulders and blocks, are also occur in the small scale rock-falls. Almost everywhere there are closed karstic forms, in state of small cavities and emptinesses. Seismotectonic landslides near Meydancık are connected with this rock. The carbonaceous rocks of Senonian age create the united water-bearing complex, which is located (upward) between relatively weak permeable volcanogenic suites. The flooding of complex is areal, layered-fractured and jointy-karstic. The good collecting properties stipulate the discharge of springs 0,02-3,0 l/sec. The waters are hydrocarbonaceous calcic. Their total mineralization is 0,1-0,4 g/l, rarely 0,8 g/l. The waters are not aggressive towards the cement. The water-bearing complex is recharging by atmospheric precipitations and from water-bearing complexes which are located in higher locations.

The some index and mechanical properties of the carbonacous formation rocks are given Table, 7

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Table, 7. The some index and mechanical properties of the carbonacous formation rocks (Tsagurishvili, 1976). Water Unit absorbtion Poro- Coeff. of Coeff. of Name of volume according sity Limits of the strength (MPa) frost- frostening weight to weight. resist.

Rocks (g /cm3) (%) (%) in dry in water after condition saturated freeze condition. Pelitomorphic 2.41 1.79 4.31 7.72 ------Limestones Organogenic 2.3-2.7 0.21-4.47 -- 80.0- 70.0-187.3 39.0- 0.62- 0.69-0.92 Limestones 200.0 190.0 0.90 Marls ------19.4-35.0 16.0-25.0 -- -- 0.66-0.69 Limy marls 2.79- 1.07-1.64 -- 8.37-55.2 66.5-51.3 ------4.20 Sandy 2.59 0.72 -- 86.5 83.7 84.8 -- 0.97 limestones

Contact-metamorphic formation The formation contains Jurassic-Lower Cretaceous geological-genetical complex of metamorphic rocks. Rocks of this complex are the oldest, in the limits of the studied territory outcrop only in Turkey.Their outcrops are located in the southern part of Karçal range, heads of the left tributary of Şartul dere, Karçal dere, areas of the Ortaköy (Berta) town and Taşucu village. Lithologically the complex is represented by clayey and crystalline shales, sand- stones and conglomerates. Clayey and crystalline shales, which occupy almost half of the geological section, are developed together. Their separate layers or small benches change or alternate each other. Shales are grey or dark grey, sometimes blackish. Sensible rocks are strong and dense. According to the engineering-technical data, they belong to hard rock group. Sandstones are grey and light grey, fine and coarse grained. By the mineralogical composition they are mica-arcosic and arcosic-quartzic or polymicritic. 60-75 % of the grains are quartz, rarely feldspar and plagioclase. Cement is of contact type, carbonaceous or carbonaceous-clayey. The sandstone belongs to a highly strong hard rock group. Slopes of Karçal range is devoid of plant cover, in this zone the complex development, is needed. Inclination of the slopes is rarely less then 200. In such conditions intensive washing out and denudation of the cover rocks take place. There is no place where the whole section of the weathering is seen in the limits of the complex. On the surface is outcropped the lowest clumpy and hidden jointing zones. The bottoms of slopes, accumulate very mobile thin-sheeted and foliaceous road material. Sandstones are in different size, mostly flat fragments, from several cm. to 0,5-0,7

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m. in longitudinal direction. Low stability against the weathering agents and high temp of denudation stipulate permanent rejuvenation of the slopes build these rocks. On this slopes recent geodynamic processes caused small volume rock-avalanches, taluses, break off the boulders and other gravitational processes of that type. Rocks of this complex are characterized by weak watercontent. Underground waters are only in the Upper part of the section, in the weathering zone of the crust. By the circulation, there are only joint waters. Weak watercontent of the rocks can be explained by their limited distribution and thin jointing, connected with low collecting properties. Discharge of springs is 0.01 l /sec, rarely 0.1 l /sec. Waters are hydrocarbonaceous calcic, with general mineralization 0.3 mg/l, fresh, usually not agressive.

The some index and mechanical properties of the contact-metamorphic formation rocks are given Table, 8.

Table, 8. The some index and mechanical properties of the contact-metamorphic formation rocks (Shvelidze, 1982). Water Unit absorbtion Poro- Coeff. Coeff. of Name of volume according sity Limits of the strength (MPa) of frost- frostening weight to weight. resist.

rocks (g /cm3) (%) (%) in dry in water after condition saturated freeze condition. Sandstones 2.51- 0.19-2.77 0.51- 221.0- 190.4- 154.1- 0.81- 0.86-0.93 2.70 7.46 255 238.8 220.1 0.92 Clayey 2.61- 0.24-0.36 2.0- 83.6- 55.4-84.6 51.0- 0.61- 0.66-0.92 shales 2.71 2.07 91.4 78.6 0.86 Clayey 2.5-2.65 0.29-0.87 2.15- 74.0- 48.0-75.0 50-70 0.71- 0.7-0.9 shales 3.9 81.0 0.91 (weath)

Magmatic formation Magmatic formations are composed of intrusive and extrusive rocks. The former is represented by the geological-genetical complex of Tertiary and Cretaceous rocks, the latter is represented by the geological-genetical complex of Goderdzi formation andesitic- dacitic effusives and geological-genetical complex of Akhalkalaki formation andesitic lava flows. Geological-genetical complex lava rocks of Akhalkalaki formation , are widely exposed in Javakheti mountains, within whole Akhalkalaki plateau. On the territory of Turkey, it is developed around Akkiraz, Öncül, Binbaşak and Çıldır villages, in the east of Khozaphin (Aktaş) lake and surrounding area of Çıldır lake. In Georgian side, it covers

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Goderdzi formation volcanics. But in Turkey, lava rocks of Akhalkalaki formation are exposed in the form of isolated fragments. The complex is mainly presented by the doleritic alkaline lavas, andesitic covers, lacustrine clays and rarely interbeds of diatomite and volcanic ash. Microscopic analysis of basalts and dolerites is very difficult. Different parts of the lava flow are constituted by the basalts and dolerites. Thickness of covers varies from 1-2m to 20-25m. By the marks of strength they belong to the solid hard rock group. Under the influence of weathering, along the initial fractures, they disintegrate at first into 0,4-0,5m, sometimes 1-2m size blocks, after creating sharply angular medium size road material. Under the influence of weathering agents, lava flows and covers break into coarse blocks and road material. This coarse detrital material create numerous taluses, rock- avalanches and stone streams. On the leveled off surfaces, where speed of denudation is low, complicated profile of crust of weathering is remained. Fine-dispersional zone is 2-25 m. and is represented by the brown loams with inclusions of fine-grained fragments. Road material horizone is 0.6-1.0m thick, where most part of detrital material is argilized. Thickness of the clumpy zone is 5-7m. The complex also includes varieties of sedimentary rocks, which are represented by lacustrine and swampy-lacustrine-alluvial polygenetic sediments. They are widely exposed, especially between Akhalkalaki vilage and Çıldır lake. Lava flows and covers are heavily fractured and water saturated. Only fracture water is developed. Watering of rocks is areal and unequal. Especially swally troughs of the old relief, covered by the young lavas are intensily watered. Places where they are cut by recent erosion net, are characterized by the frontal shows of springs with high discharge, when on the surface of the plateau springs are rarely shown. Waters have low mineralization, mainly fresh or ultra-fresh. By the composition they are hydrocarbonaceous-chloridic magnesium-calcic or calcic-magnesium-sodic.

Geological-genetic complex of andesitic-dacitic effusives of the Goderdzi formation are located on a wide territory eastwards of Arsiani range. Erusheti mountains, Ardahan plateau and large part of Arsiani range, southwards and eastwards the Goderdzi pass are wholy built by them. Eastern border comes along the Khertvisi - Kurtkale segment of the right bank of the Kura river, canyon like ravine, where it plunges under the relatively younger lavas and creates substratum of Akhalkalaki plateau. Akbaba mountain massif, east of Çıldır lake is also built by this sediments. Together with the areal spread, the rocks of this complex are characterized by the continuous sediments and unsteadiness of varieties. Complex is mainly presented by andesites, andesite-dacitic lavas, tuffs, tuff and lava breccias, tuff-conglomerates, basaltic covers, in some places coloured clays and argillizated tuffs. The lower part of the

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geological section is predominated by lava and tuff breccias, and in the upper part tuffs and lavas. Within the Goderdzi Formation volcanic ash, volcanogenic agglomerates, cinder and other similar rocks are present in the form of lenses, pockets, cones and other bodies. The volcanogenics of this kind are half-hard, waekly cemented, easily disintegrated and weakly water-resisting rocks. They are directly connected with the development zones of recent geodynamic processes. At the heads of the Skhalta river and on the right bank of the Potskhovi (Posof) river, on the north slope of Ulgar mountain, within the Goderdzi formation the mudflow hearts are developed. This hearts can continously support mudflows by hard material. In some places rocks of complex include 2.5-13.0 m. thickness of diatomites in the state of lenses and small layers. The data of laboratory studies of Goderdzi formation rocks show that they belong to hard and half-hard rocks. They are not only a good basement for any building, but also can serve as good building material. The main part of the spreading of this rocks, is on the high mountainous nival zone. Their intensive physical weathering process continues, instead of their frost resistance. As a result, rocks disintegrate by fragments from several cubic centimeters to several cubic meters. Such places are cut by recent ravines, causing underground waters frontal discharge. The waters fresh and ultra-fresh comprise low mineralization. It is necessary to mark that the rocks of Goderdzi formation are covered by polygenetic conglomerates of Damal formations on the wide areas of Ardahani plateau in Turkish side. The description of the formation is given below in Table, 9.

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Table, 9. The some index and mechanical properties of the magmatic formation effusive rocks (Tsagurishvili, 1979; Giguashvili, 1976).

Water Unit absorbtion Poros Coeff. of Coeff. of Name of volume according ity Limits of the strength (MPa) frost resist. frostenin weight to weight. g

Rocks (g /cm3) (%) (%) in dry in water after freeze condition saturated condition. Goderdzi suite. Tuffs 1.84-2.07 5.1-12.7 12.2- 2.15-71.2 9.2-54.0 8.7-59.1 0.68-0.94 0.65-0.76 1.92 8.87 30.1 53.9 37.7 43.0 0.8 0.7 24.7 Andesites 2.20-2.43 1.35-1.87 40.3-67.4 34.6-68.1 32.8-67.4 0.95-1.0 0.86-0.97 ------54.5 51.7 54.1 0.98 0.95 Andasite- 2.14-2.69 0.68-1.87 24.3-149.3 23.0-140.6 20.7-140.1 0.84-1.0 0.86-0.95 dacites 2.38 1.35 -- 73.0 68.4 67.6 0.92 0.93 Akhalka- laki suite. Dolerites 2.21-2.78 0.98-3.08 28.8-142.8 21.7-119.1 17.1-110.9 0.80-1.0 0.71-0.89 2.39 2.04 -- 108.8 73.6 71.1 0.98 0.78 Andesites 2.53-2.67 0.38-1.27 104.4-142.9 31.6-122.6 73.4-124.5 0.96-1.0 0.36-0.99 2.58 0.82 -- 125.3 77.1 106.3 0.98 0.85

Geological-genetical complex of intrusive rocks consist of intrusive bodies of granitoides, which are cutting Jurassic shales, Cretaceous, Middle and Upper Eocene volcanogens, within the studied territory. On the territory of Turkey, intrusive bodies, with the size of 0,5-1,0 square kilometers areas, are marked near the Murgul dere, Aktaş, Tütüncüler, Karaali, Camili, Çağlıpınar,Tepebaşı, Okçular, Baykent villages. Many small bodies are exposed between the Ilıca and Pınarlı villages. The granitoide intrusives occupy several square kilometers areas on the ridge of the Karçal range and in basin of the Karçal river, and between Ortaköy and İnecik. Intrusives cover 10-14 square kilometers total area near the Kedi, Merisi and Namonastrevi (Georgia). Small intrusives are exposed near the Uchanba, Chakvistavi, Jocholi and Charnali. The complex does not have large areal spreading, but it is distinguished by varieties of composition. Near the Kedi and Merisi, they are mainly represented by syenite-diorites, grano- syenites and grano-diorites. At the Namonastrevi, syenites, syenite-monzonites, syenite- diorites and monzonites are the rock types encountered. They are characterizated by the imperceptible and frequent passing into the each others on small distances. They are dark coloured rocks, usually pinkish and pinkish-red varieties. In the peripherial parts of intrusive bodies are the part of deep contact zones, which are related to hydrothermal process - pyritization, carbonatization and sericitization. Thickness of such zones vary from several tens of metres to several kilometres. 419

Weathering of rocks is followed by oxidation of sulphides and formation of iron hydroxides, gives the rocks yellow or reddish colour. In the weathering rocks, almost everywhere has fine-graine dispersional zone which is represented by loams and clays with small inclusions of road material. Thickness is 2-5 m. The road material zone has small thickness or falls out at all, from the profile. Boulder and hidden-jointing zones, which are located below, have 10-15 m thickness. The weathering of intrusives are connected landslides, rock falls and rarely taluses, mudflows are observed in some places. Normally intrusives are hard rocks with their stability and scarpness. The main characteristics of their hardnesses is given in Table, 10.

Table, 10, The some index and mechanical properties of the geological –genetical complex of intrusive rocks (Labartkava, 1969).

Unit volume weight Limit of hardness Water Coefficient (g /cm3) absorbtion In dry condition in water of softening Name of rocks according to (MPa) saturated weight condition (%) (MPa) 1. Syenite 2.69 3.23 209 167.2 0.80 2. Diorite 2.75 0.89 135 122.7 0.91 3. Gabbro-syenite 2.97 0.58 237 221 0.95

Characteristics of hardness of granitoides were not obtained on the territory of Turkey, but they outcrop as massif form. Their character and peculiarities indicate that these rocks also have high hardness. It is necessary to mark that the slopes covered by wood almost everywhere, and have the small thickness of weathering along the whole profile and 1-2 m. and thickness fine-dispersional and road material zones. In the most part of territory, plants are destroyed and the boulder zone of basic rocks is outcropped on the surface. High energy of relief within the Karçal range contributes to intensive development of denudational processes and outcropping of rocks. In this places, intrusive rocks are connected small volume rock-falls and taluses. Heavely jointed nature of intrusive rocks determines their water content. According to the type of circulation, there are only fracture waters. Discharge of springs varies from 0,01 to 0,5 l/sec, which indicates the differencies in flooding of water-bearing complexes. The maximum discharges are connected with high places hypsometrically. Waters are hydrocarbonaceous calcic-sodic, hydrocarbonaceous chloridic-calcic-magnesium or hydrocarbonaceous sulphatic- sodic-calcic. Total mineralization - 0,1 gr/l. The water- bearing complexes are alimentated by atmospheric precipitations and condensation

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processes.

Formations of Continental Cover Rocks

Coastal-Deltaic Formation Coastal-deltaic formation, within the investigated region, takes narrow seaside stripe, where Holocene marine and Quaternary alluvial-marine genetic type sediments are united. They build basicly low accumulative plane-terraces, beaches and coast shelfs of the littoral. Their facial variety, forming process and evolution is connected with the changes of the Black Sea and the World Oceans, with the volume of solid material, transported by rivers, with the coast-line litho and morphodynamics, and with the little amplitude, different vertical movement of this stripe structural blocks.

Sediments of the seaside and coast shelf (mQ4) are represented by the narrow interrupted stripe on the land. The width of the terrigenic sediments in the zone of orogenic type shelf (zone of 100m isobath) varies from several hundreds of metres to 3-11 km and depends on the intensity of the elevation or dipping of the coast-line structural blocks in Holocene. It is established that the rate of average uplift of Tsikhisdziri and Sarp-Kalendere structural blocks is 2 mm/year, when recent rate of subsidence of the Batumi-Chorokhi structural block is 0,5mm/year. Maximum uplift should be exposed along the seacoast zone of the Eastern Pontides. Speed of the uplift along the shore is 9,4 mm/year. In the recent marine sediments of the coast shelf 3 stripes are sharply distinguished: in the zone of shingle elevation structure, rubbly-pebbly, sandy and silt. Pebbly fraction which is represented by the fragments of porphyrites, tuffs, tuffbreccias and granitoides, spread to the 3-7 m. depth; then to about 5-25 m. depth are located polymictic sands, which are containing heavy and light minerals. Sands are represented by middle and fine fraction, (predominate fraction 0,25-0,1mm), thickness about 30 m. Sands are loose, hardnes fluctuates 2,66-2,71 gr/cm3, natural humidity 20-30%, coefficient of porousity 0,8-1,2, angle of the internal friction 20-25o, adhesion 0,03-0,06 pa, specific resistance of penetration 0,02-0,07 pa. (Janjgava, 1991). Silty grounds, which spread mainly 5-25 m down from sea level, are characterized by aleuritic and aleurite-pelitic structure. This formation occured in weak alkaline environment Ph-7,7. In granulometric composition of silts predominates fraction 0,05-0,01 mm, which is hydromica-caolinitic and montmorinollitic. Coastal sediments of the land, which come by the narrow stripe along the seacoast line, mainly are represented by the beaches. Width fluctuates from several to 100-250 m. The widest are Batumi and Gonio sections; on the Makhinjauri and Sarp-Hopa segments, where significant rising and sea coast directly edjoins the abrasional hard rock clifs, beach is almost absent. In formation of Gonio-Batumi considerable width beach solid material has

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the main role evacuated by the river Chorohki, which has almost moved 100% to the North- East. Beach material is loose, with high water conducting features. Chemical composition of water is hydrocarbonatic-calcic and chloridic-hydrocarbonatic. Near the sea coast, mineralization and content of chlor-sodium ions significantly rises. On the Tsikhisdziri, Chakvi, Kemalpaşa, Ardahan and Sisikli sections 25 m. thick fragments of the old Black Sea terraces, which are built by the weakly cemented, different granulometric copmosition are outcropping. They are well rounded rubbly-pebbly conglomerates, with sandy-gravely filler. The latter is also represented by the lenses and pockets. Conglomerates are sufficiently weathereded and is partly subjected to the process of lateritization. These sediments hold the vertical wall in natural conditions. Complex of Alluvial-Marine Sediments (amQ) is widespread within the recently subsiding structural block of Chorokhi-Batumi area, which is morphologically the Kakhaberi plain-lowland. Lithologically it is represented by alternating of gravel-pebbly fractions with sands and loams indicating frequent changeability of the hydrodynamic regimes of the Black Sea and the Chorokhi river. Their average thickness is about 100 m. This sediments are covered by swamp type silty loams and turf on the southern edge of Batumi and in isolated areas of accumulative plain. In the alluvial-marine complex, the gravel-pebbly detrital fraction is mainly located on the upper part of section. They are located in state of layers and lenses. The content of shingle is not more then 10%. The detrital fraction is well treated. Petrographicaly they are represented by all basic rocks which are building the Chorokhi river basin. Mainly andesite-basalts and andesites (75%), granitic material, tuffs and tuff-sandstones (5-8%), basalts (2%) and the other sedimentary rocks are about 9%. The fill of detrital fraction is mainly the fine-grained sands, their rate is about 10-15% to 30%. Sometimes they include thin lens-shaped interbeds. The volumetric weight of detrital fraction is 1,95-2,3 in one cubic metre, coefficient of filtration is 35-40 m/day, the angle of internal friction is 40o, the modulus of deformation is 40 MPa, and the carring properties are 5-6*105 Pa. In the alluvial-marine sediments loams, like sands, are also represented by alternation of layers and lenses, thickness vary between 1.8 -26 m. They are dark grey and yellow-grey coloured, with mainly medium and light composition, and significant participation of fine-grained sands. Loams are characterized by high dampness and by soft-plastic consistency in whole section. So, the alluvial-marine sediments, in engineering-geological standpoint are presented by heterogenous friable not cemented and by weakly cemented complex of rocks, with changeable permeability and heterogenous carring properties. With especially low geotectonic indexes the swamp type grounds are distinguished. Because of this, on such area the building conditions are very complicated.

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Table, 11, Generalized indexes of physical-mechanical properties of the alluvial-marine sediments (Giguashvili, 1976; Tsagurishvili,1979). Granulometric composition (%) Plasticity Resistance of ground on Natural Unit Poro- displacement Volume No Soil type Water Weight Sity Coarce Sand 2- Silt Clay< Liquit Plasticity Natural water content Water saturated Soaking Swell- 3 grains>2mm 0,05mm 0,05- 0,005 Limit Limit (%) in 24 ing % content (g/cm ) (%) 0,005 Mm (%) houres (%) mm grad. 0 Kg/cm3 grad. kg/cm3 0 1 Sediments, mainly 18* 1.71 41 0 15 19 27 44 18 14 03’ 0.3 11 0.3 in 3 44 Marine 26 1.96 48 2 28 45 57 50 26 25 45’ 1.3 09’ 0.85 hour 50 clays 14 36’ 15%

Loams 21 1.68 40 0 13 18 36 36 79 16 15’ 0.23 0.1 36 37 1.92 51 11 43 58 69 41 15 34 37’ 0.59 9 11’ 0.27 in 48 41 18 45’ hour do not 2 Sediments of I-st ma- 12 1.76 39 0 8 26 18 48 19 12 29’ 0.2 7 35’ 0.1 rine terrace 38 1.97 58 31 43 61 56 31 22 15’ 0.76 14 29’ 0.23 clays

Loams 17 1.62 41 0 25 27 21 45 9 14 18’ 0.25 9 15’ 0.12 31 1.99 60 5 58 48 60 54 16 23 54’ 0.48 12 53’ 0.16 Sandy loams 9 1.55 0 41 24 17 27 4 15 00’ 0.18 5 00’ 0.1 25 1.96 17 72 30 35 41 5 27 39’ 0.25 6 49’ 0.17

*) In numerator – min. value In denumenator – max. value

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Formation of The River Ravines Sediments of this formation occure almost everywhere and are developed in almost every river ravines. Formation unites 3 geological-genetical complexes of rocks - two alluvial (of lower and upper terraces) and mixed alluvial-proluvial deposits. Complex of the recent alluvial sediments of lower terraces includes rocks, which build river-beds, flood plains and terraces of big rivers as Chorokhi, Adjaristskali, Kura, Murgul dere, Şartul dere, Potskhovi (Posof), Kvabliani and their numerous tributaries. Heights of the flood plain shingles vary from 0,5 to 2-3m. above river level. Surfaces of the first above flood plain terraces are not more then 8-10 m. Lithologically, rocks of the complex are mainly represented by the rubbly shingles with sandy fill, sands and rarely by sandy loams. The latter, together with ground horizon, often cover shingles. In the valleys of Kura river, Potskhovi (Posof) and Kvabliani rivers, thickness of shingles reaches 50-60m, and on the lateral tributaries it varies in limits 5-10 and 2-5 m. The thicknesses are considerably characterized rivers of the Black Sea basin. Thickness of the loosely detrital alluvial material of the Chorokhi river, in limits of the Muratlı village reaches 69 m. and near the Borçka town 47,2m. Sediments of the Adjaristskali river near the Makhuntseti village, are 48-50m. Upwards, near the Merisi village, reaches 35m. Shingles and rubbly shingles with sandy and sandy-gravely fill and also sands are loose constitutions. Detrital material is well rounded, different sized, from the fine gravel to coarse boulders. They are represented by the effusive, sedimentary and metamorphic rocks of different age from Jurassic to Middle Quaternary. There is a well treatment and sorting of alluvial material of the main big rivers. In granulometrical composition of the alluvion of the Kura river and its tributaries predominates rudaceous rubbly-coarse pebbly composer (to 70%). Together with it, here are boulders more then 200 mm - 12-15%, fraction from 100 to 200 mm - 28% and fine and medium shingles (20-100 mm) - 25-32%. Sandy-gravely and sandy-loamy fill composes 25-30%, and fraction is less then 2 mm - 3-8%. Coefficient of filtration of shingles is 5-10 to 8 m/day, angle of the natural scarp in air-dry condition - 29-370 and additional pressure is not more than 0,6 MPa. Rudaceous formations in scarps, especially near the river-beds are unstable. In alluvial sediments of the Chorokhi river basin predominate shingles of 50-100 mm fracton - 35 %; boulders of fine and medium size (100-200 mm) - 16%; other boulders (more then 200 mm) - 14%. Sandy-gravely fill composes 35% from common mass. Coefficient of filtration of shingles is 25-30 m/day; angle of natural scarp in air-dry condition is about 360 and carrying capability - about 0,4 MPa. Sandy loams are from light grey to light brown, long, heavy and dusty. They are bedded in alluvial coarse sediments of rivers in case of slim lens-shaped interbeds or cover shingles and sands.Volume weight of sandy loams is 1,46 gr/cm3; specific weight - 2,7

402 gr/cm3; porosity - 57%; number of plasticity - 7; angle of internal friction - 250; adhesion 0,022 MPa, carrying capability 0,3 MPa. The recent geological events are erosional and fluvial processes. Erosional processes are actively revealed along the every river of studied area. Active abyssal erosion in mountainous parts in case of planation of the river-bed, is changing by the lateral undermining, which reach quite a big scales in case of floods. Fluvial processes occure in forming and disappear of holms, channel banks, wandering fans and other morphological forms, characterizing for flood plains and river-beds. Often, bank cavings and inundation of the area in case of flood occure there. Rocks of the complex everywhere are flooded. In the shingles and sands of the first, flooded plain terrace and fluvial facies, often are formed powerfull flows of the ground waters. Depth of their location changes from 0,5 to 5 m. Alimentation of the underground horizons of the given complex is going by the infiltration of river waters and atmospheric precipitations. Relaxation - in the river-beds and flood plains. Discharge of springs changes from 0,1 to 3 l/sec. Flooding of rocks is areal and character of circulation is porous. Underground waters are soft, with low mineralization (about 0,5-0,6 gr/l) and hydrocarbonaceous calcic or sodic. In relation with cement they are usualy not aggressive. The complex of alluvial sediments of high (upper) terraces is developed in state of small fragments in valleys of the Adjaristskali, Potskhovi and Kvabliani rivers. Because of limited areal distribution, they could not be shown on the map. The widest areal spreading, rocks of this complex, are within Akhaltsikhe depression, between Atskuri-Akhaltsikhe and in Aspindza regions. The complex includes rocks of the second and higher terraces of the Kura river basin. Description of the synchronous formation of rocks of mountain glaciation with the high terraces of the Chorokhi river is given below. All of them belong to Pleistocene age. Lithologic complex is presented by the conglomerates with interbeds of loams and sands, and the shingles with sandy fill. Their thickness is about 5-10 and 15 m. On the separated areas their thickness is more than 20 m. Conglomerates are developed on the fourth, fifth and much higher terraces. They are grey, dark grey and brownish-grey and have heteropebbly, sandy-clayey and sandy carbonaceous cement. The cement is usually contact-porous but often occures also as basal type. Cement and detrital material on the highest terraces are loosed by the weathering. Degree of cementation of the lower terraces is low. Alluvial conglomerates are characterized by the well sizing and treatment of rudaceous material. On the left slope of the Kura river ravine, in the Damal village areas, conglomerates of the tenth terrace are covered by the Middle Pleistocene dolerites of the Kura flow (see photo, Fig., 1).

403 In the high terrace cusps, conglomerates carry vertical scarps along the whole thickness of the layer and according to their level of strength, they belong to half hard rocks. Shingles are also widely spreaded in the mentioned complex. They often replace conglomerates along the spreading. As a rule, shingles of the high terraces have sandy and sandy-clayey fill. Its quantity, according to granulometric analysis is 10-20%. Shingles in the Fig., 1, Alluvium of the high terraces of Kura river, scarps are relatively stable and burried under the dolerites of the Kura flow. create almost vertical walls with 2- 3 m height. Permissible load on the ground is 0,6 MPa. Loams are developed in form of isolated interbeds and lenses with thickness from 0,4-0,9 to 1,8-2,5m. They are light grey, brown, yellowish, sometimes with reddish shade, carbonaceous and not carbonaceous, from light to heavy. Physical-technical properties of these rocks are as follow: natural humidity - 6-18%; volume weight - 1,53-1,84 gr/cm3; specific weight - 2,64-2,76 gr/cm3; porosity - 38-49%; composition of the sandy fraction - 10-41%; dust - 27-58%; clayey - 15-36%; number of plasticity - 8-14. Loams inundate in 3- 14 min. Coefficient of internal friction in natural dampness - 0,038-0,090; angle of internal friction - 21-420; adhession - 0,021-0,09 MPa. Permissible load on the ground - 0,2-0,25 MPa. In the Kura river ravine, between Dviri-Chobiskhevi and Tmogvi-Vardzia fine remains of lacustrine-fluvial sediments of Middle and Upper Pleistocene are deposited. Lithologically, they are represented by the clays, loams and rarely sandy loams, alternated with interbeds and lenses of sands. Near the Chobiskhevi and Dviri villages, in the wall of the scarp of alluvial-lacustrine sediments, on the left bank of the Kura river is well observed, banded-interstratificated clays and sands of the two different generations are divided by the 3-4 metre thick interbeds of the Chobiskhevi river old mud debris cone's rudaceous formations. (Fig., 2). Periodically coarse mud debris cones caused damming of the Kura river and forming of temporary reservoirs (intermittent impounded bodies), where before the nextbreack of the commissure, was settled clayey-sandy material.

404 Flooding of the complex weak in case of good drainage of the fragments of high terraces. But in some places stable horizones of the underground water are forming, alimentate springs with discharges from 0,1 to 2-3 l/sec. Waters are usually fresh, with mineralization 0,2-0,5 gr/l. From the recent geological processes within the development of the given complex are fixed gully erosion, inrushes and very rarely landslides. Complex of the alluvial-proluvial sediments is widely spreaded all over the studied area. Especially they are developed widely in Adjara, on the parts of the Akhaltsikhe depression, foothhill parts of the Trialeti range and Erusheti highland. Within Turkey, sediments of the complex are developed in places near Posof and more locally - in lower flow of the Murgul dere river.

Almost all of the lateral tributaries of the Kura, Adjaristskali, Dzindza, Kvabliani, Potskhovi and some of other rivers, periodically evacuate or well rounded alluvial materials or proluvial-silt formations. Small tributaries are mainly characterized by the mud debris cones. As a result, along the river-beds alluvial - proluvial material is forming and along the banks - trains of the proluvial sediments also. Their thickness vary in wide limits, from 2-5 to 10- 20m. Especially sharply it is revealed along the Kura river, on the segment Khertvisi-Aspindza, in the middle flow of the Potskhovi river, along the Skhalta river and in lower flow of the Murgul-dere river. Fig., 2, Lacustrine sediments of two generation, created Lithological composition by the damming of Chobiskhevi mudflow. of the complex is distinguished by its motley and is built by the shingles, rubbly-shingles, clays, loams, sands and sandy loams.

405 Rubbly-pebbly sediments are dominant in limits of development of Middle Eocene rocks and clayey-sandy alluvium-proluvium in Middle Eocene and Oligocene. Mixed material is created in development limits of Goderdzi formation rocks. Goderdzi formation in Adjara supplies mainly rubbly-pebbly material and in region of Posof - clayey-sandy with rubbly-pebbly. Rudaceous sediments of debris cones and proluvial trains are in places sharply different from river-bed alluvium-proluvium. They differ in the bad treatment of material, absence of sharp sizing and granulometric composition. Here is significantly increased quantity of clayey-sandy material which, is not a fill but basic mass in some places. Comperative analysis of granulometric composition show that river-bed proluvium contains coarse boulders (fraction more then 200 mm)in limits of 3,2-40,8%; silt (fraction less then 1 mm)about 2,5-18,7% and in limits of debris cones and proluvial trains content of this fractions accordingly are 2,0-16,5 and 6,2-32,5%. Permissible load on rubbly shingles of alluvial-proluvial sediments is about 0,6 MPa and for forming of debris cones - 0,4 MPa. Clayey-sandy rocks are widely developed within Akhaltsikhe depression and in Posof area. Here they are sharp reddish. Clayey-sandy rocks together with rudaceous material build areas among separate debris cones, creating whole trains, extended along mud-bearing waterflows. In sections predominate clays and loams. Natural dampness of clays is 20-35%; volume weight of damp ground - 1,74-2,03 gr/cm3; specific weight - 2,68-2,8 gr/cm3; porosity - 36,53-52,16%; number of plasticity 24- 27; angle of internal friction - 14030'-21049'; adhession 0,03-0,085 MPa, after water saturation angle of internal friction reduces to 12068'-17046' and adhession to 0,025-0,07 MPa, swelling - 2,4-7,0 %. Half of the samples soak in 24-27 hours and the rest do not soak at all. Rocks of the described complex are flooded unevenly. Clays and loams built upper part of the debris cones and proluvial trains, are distinguished by the weak watery nature. The most intensively flooded detrital-pebbly formations and sands, built lower parts of the debris cones and flood plain river-bed alluvium of relatively big waterflows. Most wholly ground waters are revealed in the lower parts of the small rivers and debris cones, where they in case of profitable conditions of the relief are pinched out in state of springs or frontal shows. Such springs are almost in every ravines of lateral tributaries of the big rivers. Their discharge is from 0,1 to 1,5 l/sec. Waters are mainly hydrocarbonaceous calcic sodic or hydrocarbonaceous sulphatic-calcic-magnesium. Mineralization - 0,6-0,8 gr/l. The recent geological processes in limits of complex distribution, often occure mud phenomenons. On the surfaces of the trains and debris cones, gorge forming process is going on and river-bed processes and linear erosion are widespread along the river-beds.

Slope Formation

406 This formation is characterized in the studied territory by universal spreading. The contrasting of relief and climate, the litho-petrographic varieties of basic rocks are creating especially profitable conditions for forming of different genetic groups and complexes with different composition and peculiarities. According to the character of slope formations there are 3 genetic complexes: eluvial-talus, colluvial and hypergene-lateritizated eluvium. Complex of The Eluvial-Tallus Formations (edQ) The complex of eluvial-talus sediments in the system of slope formation take especially important place both by the extensive development and by the conditions of forming of the complicated engineering- geological situation. They are spreaded everywhere on the studied area and cover the basic rocks ranging from Jurassic to Quaternary. As the title shows, forming of this sediments is connected with eluvial, tallus and combined conditions of sedimentation. Separation and distinguishing features of them by the genetic signs (features) is very hard and almost impossible. They often contain a low quantity of formations of other genetic types of cover rocks but, to distinguish them is impossible on the map because of scale. Usually on the steep and steeper slopes of the Karçal , Erusheti, Balıklı dağ and other ranges and also in places of Goderdzi formation lava rocks and young lava covers development, (low mountainous chains and uphills of Ardahani and Akhalkalaki plateaus), thickness of the eluvial-deluvial formations is not more than 2,0 m. On the rest part of the territory thickness of this sediments is within the limits of 2-5 m and 5-10 m, rarely 10-15 m and in separate cases and on the local segments is more than 20 m. Lithologically eluvial-tallus formations are represented by the clays and loams with inclusions of detrital-road material and with burried soil interbeds. Attendence of the latter is a proof of rythmicity and alternation of the sediments of slope eluvion and tallus. The given complex is intermediate between exactly eluvion and products of plane washing out. On the substratum of the volcanogenic-sedimentary formation, eluvial-tallus sediments are represented by the coherent rocks and coherent with detrital. The first - loams and clays often occure in the limits of old leveled off surfaces and on the gentle slopes. The second - loams and clays, with inclusions of road material and gruss, cover the basic rocks on the steeper slopes, where intensive silt wash is taking place. In both cases mineralogical composition of the clayey fraction is represented by the minerals of hydromicaceous composition, sometimes with admixture of gypsum or montmorillonite. In chemical composition of the grounds is marked by the relative increase of aluminium oxide - to 18,57% and ferrum oxide - to 9,47% when content of silicium oxide is 48,69%. Near the zones, deep hypergenesis of the basement rocks is marked by the high porosity of loams - 51% and especially of clays - to 56%. On the rest part of the territory

407 porosity reduces to 39-42%. Accordingly changing high levels of the natural humidity from 36 and 45% to 11-20%. Often, especially on eastern part of the territory, eluvial-tallus formations contain burried horizones of soil with thickness 0,5-1,2m. Clayey minerals mainly are represented by the montmorillonite group. Relatively high content of organogenics and montmorillonite in burried soil horizones points, that forming of these horizons was going under the conditions of smooth relief and half arid climate. Clayey rocks of eluvium-tallus created on the substratum of terrigenous formation are distinguished by the high colloidal activity. Almost in every sections of these rocks, highplastic clayey varieties predominate. Number of plasticity never falls down to 19-20 %. The highest indexes of plasticity characterize clayey rocks, formed on the marly formations of Upper Eocene and Oligocene with number of plasticity 26-22 %. Eluvial-tallus formations occur in the basic environment of generation and development almost every varieties of recent exogenic geological processes: landslides, mudflows, areal and linear erosion, cryogenic processes etc. On the all of the studied area, sporadic inundation of eluvial-tallus rocks is marked. On the most part, they create whole horizons of ground water. The eluvial-tallus formations on the substratum of hard and half hard rocks of Jurrassic,Cretaceous and Eocene age are most inundated. The rocks lessely inundated are covering clayey and marly formations of Paleocene-Lower Eocene and Eocene-Oligocene age. The complex of colluvial sediments (CQ) is represented by boulder-detrital material of basic rocks and by landslide - rock-fall accumulation products with significant participation of separate blocks and benches. Territorialy, they are characterized by isolated spreading, although they are lying significant areas. The wide spreading colluvial sediments are stipulated by high energetical potentials of relief, by sharp contrasting of temperature, by important outcrops of basic rocks and their strong tectonic disturbance, by high neotectonic tensity and seismicity. Colluvial sediments are composed of 3 main groups: 1. Talus, which occupy the bottom of the rocky-cliffs. On the base, this taluses is going the continuous renovating of the gravitational exposition. The most of this formations have high coefficient of movement (0,5-1,0). They are mainly recharging springs of the gravitational mudflows. Often the movement of talus cone and train materials is moving so fast, that creating the rock-fall shaped chaoticly dispersed covers in huge thickness. The speed of stone fall's movement depends on lytho-petrologic composition of material, on the size and shape of fractions, on the degree of flooding and dampness and on the shape of contact with basic rocks. By the maximum rates of movement are distinguished the tabular- platy smooth surfaced slate clays, metamorphic sheets, the fragments of argillites and marly suite. In their composition fine-clumpy material with road material fill prevail (more

408 than 80%). The tuff-breccias, tuff-conglomerates and tuffs of the Goderdzi formation are especially subordinated to the gravitational processes. According to the regime observations in many years the average volume of talus materials is 1,3-1,5 kg/m2. On the substratum, high hardness and water resisting magmatic and volcanogenic rocks continues the forming of the coarse-detrital colluvium. The abolish of critical equilibrium is not going fast, but gradualy, with collapse and fall down of the separate blocks and coarse fragments. In such taluses, the coarse clumpy-fractured material percentage is 50-70%. The size of separate boulders and blocks varies from several cm. to one meters. Their angle of natural gradient is 35-45o. In the disintagrated mass of such colluvium the total volume of fine, detrital and aleuritic-pelitic fractions is 3-12% (Fig., 3). The porosity of talus colluvion is 60-70%, volume weight is 1,50-1,68 gr/cm3, coefficient of filtration is 3-10 m/day. 2. The special areal spreading have the colluvium of stone streams on the studied territory. They are covering the gentle slopes of the Javakheti young volcanic mountainous massif. The forming of such kind sediments is under the influence of nivation-denudation processes. Degree of rock disintegration and rock thicknesses depend on the morphology of relief and on their petrographic composition. The rocks of young volcanic suite prevail the initial detrital material and their mineralogical composition does not differ from the rocks which are located under them. 3. The landslidic-rock fall sediments are created in the rocks of different stratigraphic and lithological groups. Their lithofacial composition and physical- mechanical characteristics sharply differ from each other. The landslidic sediments

developed in the Oligocene - Miocenic and Fig., 3, The character of the colluvium talus – clayey rocks have typical forming in the rocks of the Goderdzi delapsing character (mainly with fluent- formation plastic consistency). Their thicknesses vary within 3-10m. In the landslides areas, the thicknesses are more than 10 m such as the landslidic bodies of Veliköy, Pınarlı,

409 Rustavi, Vale, mountainous Adjara. Only Khavati landslide which is located in the south- west part of Akhalkalaki plateau, is characterized by 8 km frontal spreading and with total volume 10 million cubic metre. The colluvial sediments, which are developed in the Eocene and Goderdzi volcanogenic formations, are mainly delapsing type. The rock-fall material developed in the Neogene- Quaternary lavas have the same type. Commonly, the wide spreading and delapsing colluvial formations was stipulated by deep cutted erosional Kura, Pharavani, Potskhovi, Chorokhi and Adjaristskali river ravines. It is necessary to mark the colluvial formations of Murgul, Artvin, Vazri, Arıcılar, Araklı, Meydancık (Chorokhi river basin), Danispirauli, Tsablana, Tkhilvani, Chanchkhalo, Gogadzeebi (Adjaritstkali river basin), Bertakana, Nakalakevi, Vardzia (Kura river basin). Their volumes vary from 5 million to 200 million cubic metre. Especially the delapsing colluvium, fastly developes in the rocks of Goderdzi formation. Because, it is composed of tuff and tuffbreccias which are easily subordinating to the distructional factors. As a result of their washing out, the horizontal lava flows are collapsing together with rocks of Goderdzi formation. In the colluvium have significant quantity (30-40%) the fine-fractional tuff-road materials. Except the erosional influence of rivers the springs with big discharge have the leading role in the washing out and disintegration of tuffogenous rocks. Springs change the degree rock-falls into the flows, which is making the washing out of fine fraction.They are accompined by surfacial processes. Because of that, Nakalakevi village in Aspindza region, is subjected to the significant deformation. The same phenomenon take place in the colluvium of rock-falls of the Goderdzi formation. (Fig, 3). Eluvium Lateritic type Complex (eN-Q) This complex is a significant area in the studied territory and is developed in the damp subtropic zone of Black Sea coast, on the absolute marks 400-500m. They are characterized by the special astensible signs and internal properties. The study of facial and material composition of laterites, their physical- mechanical properties and conditions of occurrence have the significant meaning not only for establishment of engineering-geological properties of complex, but also to understand the regularity of development of the crust of weathering. Laterites are characterized by reddish-yellow colour. Their thickness reach to several ten metres. The lower part of lateritic zone preserve the shape of basic rocks texture, but the physical- mechanical properties, the mineral and chemical composition have nothing similar with basic rocks, and are the typical lithomarges. The existance of different hardness and value ferrumic alumina concretions are the astensible signs of laterites. The essence of laterization process is that under frequent and intensive atmospheric precipitation and increased temperatures, takes place deep physico-chemical weathering of iron and aluminium bearing rocks. Silica SiO2 and absorbed bases of Ca, Mg, Na and K are removed from rocks, where colloidal Fe2O3 and Al2O3 are accumulated.

410

Fig., 4, Processes of lateritization

Their low molecular ratio serves as an obvious indication of intensive laterization. Facies and geochemical changes of laterite rocks, their colour, thickness, weathering degree, structural composition and engineering-geological properties are determined by lithologic-petrographic composition of the original rocks undergoing active hypergenesis and by relief conditions. Laterites of the investigated territory vary in age from the Kimmerdgian up to the Quaternary. However, up to the present, paleogeographic conditions of laterization processes went on in almost the same climatic conditions: average annual temperature - never lower than 13-15o, and annual precipitation is 2000 - 3000 mm at humidification factor of 4,1. They are formed on volcanogenic rocks of the Middle and Upper Eocene, on the Cretaceous-Paleocene carbonaceous rocks, on the Oligocene-Neogene clays, on the Pliocene and the Quaternary deposits. On alkaline volcanogenic formations laterites of red, brownish-red and yellowish- brown colour enriched in aluminum oxide, iron and hydrochlorites are generated in the active hypergene zone almost is observed uniform ferritization (average content of iron oxide is 11-15%). As a result, there takes place gradual thinning of aluminum oxide and

411 thickening of silica. For these rocks, medium acid reaction (Ph 4,7-6,0) and active kaolinization are characteristic. Lithologically they are represented by loams and clays with porous, granular cloggy, loose structure. High porosity (65-70%) and humidity (42-47%) are determined by step-like aggregation. Physically bound water is asorbed inside aggregates, as well as on their surfaces, which stipulates high values of all kinds of humidity. When clay fractions are reduced by laterization detrital fractions increase up to 43- 44% in average. Thermograms of sludge fractions of typical latericized soils point out kaolinite and halloysite predominate in them. From colloids hydromica with montmorillonite admixture is encountered. They basicly have high filtration coefficient, solid consistency, high values of unit weight (2,78-2,83 g/cm2), low density rocks (1,13-1,63 g/cm3), increased strength indices (f =15-20; C=0,20-0,950 kgf/cm2) and deformations, the final value of which changes within the limits of 31-186 mm/m. In water saturated medium f decreases only by 3-5o, while adhesion decreases by 0,05-0,45 Mpa. In natural conditions, these rocks stand high angles in slopes (46-60o) at slope height of 5-15m; they are water-resistant and do not soak despite of favourable climatic conditions, the development of deep and scaled landslide processes is limited. In laterites generated on Upper Pliocene-Quaternary marine terrace deposits, kaolinite argillaceous formations dominate (50-60o). At the same time, thickness of hypergenesis notably increases from young to old terraces and argillaceous composition increases respectively. On Middle Quaternary terraces, yellowish and brownish tints of clay and loam with thickness from 3,5 to 8-10 m prevail. The composition of argillaceous fractions in clays is 38-63% and of dust fraction 52-60%. Argillaceous fraction everywhere has hydromicaceous composition with gypsum and calcite admixture. The chemical composition the basic mass consists of silicium and aluminum oxides, the amount of which in nature is 60 and 12%, respectively. The amount of iron oxide is a slighly higher. The content of finely soluble salt per 100 g of rock does not exceed 0,3 g/l. Number plasticity of rocks is chiefly within the limits of 19-20 and does not exceed 24, which is somehow connected with peculiarities of chemical composition. Yieldpoint of clays mainly equals 36-49, and plasticity point is 22-25. The consistency of rocks is solid, seldom- semisolid and in single cases - plastic. In the main, clays are of low and average water resistance, though relatively water resistant varieties are often encountered too. In some places, low water resistant clays occurrence are noticed, which apparently is connected with increased natural humidity of rocks up to 28-29%. As a whol, all kind lateritic rocks in natural conditions are characterized by high water conductivity and with normal carrying properties. On the artificial inclinations and slopes, they are relatively stable and characterized by high angles (45-60o). In the

412 conditions of high humidity, they turn into the sticky-plastic consistency and accompined by development of small scaled superficial landslides and massive accumulations.

413 Table, 12, Generalized index of phisical-mechanical properties of lateritic formations (Varazashvili and Tsereteli, 1994).

Granulometric Name of Natural Unit Specific composition (%) Plastisity Angle Cohesion volume # rocks Water weight gravity Porosity Sand Silt Clay Limit of internal kg/cm2 content gr/cm3 (%) friction (%) 1 2 3 4 5 6 7 8 9 10 11 12 1 Laterites of Batumi Clay 10* 1.53 2.76 54 9 33 17 18 5 42' 0.050 61 1.81 2.89 68 30 61 58 31 27 30' 0.150

Loam 15 1.6 2.75 46 15 42 12 10 14 03' 0.100 52 1.94 2.89 68 39 55 30 17 24 14' 0.450

2 Zebroidic laterites a) on marine terrace Loam 21 1.68 2.65 42 25 3 9 7 16 0.230 43 1.90 2.75 57 75 57 32 14 34 0.590

Clay 17 1.63 2.69 45 18 8 18 19 18 0.200 64 1.98 2.75 60 55 46 64 30 28 0.520

b) on river terrace Loam 15 1.67 2.68 42 35 14 13 7 19 0.260 29 1.69 2.74 52 68 47 28 12 22 0.010 Clay 27 1.70 2.70 45 36 8 28 18 14 0.210 41 1.89 2.75 55 45 27 63 21 21 0.550 *) In numerator – min. value; in denumenator – max. value.

402 Formations of the closed depressions Formation is represented by the 3 geological-genetical complexes: lacustrine- fluvioglacial Quaternary sediments, lacustrine and alluvial-swampy Upper Pleistocene- Holocene sediments. All of these complexes are polygenetic and distinguished with complicate genesis. In forming of each of them, except basic genetic types, straightly or slantingly take part all rest genetic types of these complexes also prolluvial and delluvial sediments. Complex of alluvial-fluvioglacial Quaternary sediments (alfgQ) is wide spread only on the surface of Ardahan plateau, between Ardahan and Damal. They are outcropped in outskirts of Hanak, Avcılar and Damal. Rocks of this complex, from east, north and west are surrounded by the glacial sediments. Complex is polygenetic. The basic genetical types are lacustrine, alluvial and fluvioglacial, with rocks of proluvial-deluvial character. Andesitic and doleritic lava covers are also present. In this case, characteristic section on the edge of the Hanak town, under the well rounded fine shingle with sandy-sandy loamy fill 0,5-1,5 m in thickness, weathered dolerites and tuffs, with total thickness 2,4 m are located. Lower part is seen as burried soil layer (0,5m) with inclusions of well rounded pebble. Yellowish homogenous lacustrine sediments, mixed with weathered tuffs, with visible thickness 2,0m. are the lowest level. The upper complex is widespread and visible part of Damal formation, represented by the rubbly-pebble, pebble with sandy and clayey fill, with interbeds of clays and loams. Typical and characterizing section is near the Arikonac village, where upper parts are located on the doleritic lava rocks 1. Medium rounded, consolidated pebble, weakly cemented by the light grey clayey-sandy material, is 5,0m thick. In the middle part of the layer, interbeds of consolidated light grey clay are observed, with 0,5m thick. 2. Fine grained pelitic sand, light grey, of medium consolidation, with interbeds of pelitic material, fine bedded with inclusions of badly rounded boulders. Thickness is 1,7m. 3. Lava rock boulders, badly rounded, size is 0,1-0,4m in section, average thickness is 1,0 m. 4. Light grey clay, thin layered, dense, with impurity of sand, with 0,4m thick lens shape interbeds of shingle and thin layered pelitic material of 0,6m thick. In the upper part of the section soil bed is 0,4-0,6m thick. Total thickness is 2,0m. Water-physical and mechanical properties of this complex have not been studied yet, but studies of outcrops give us opportunity to estimate approximately their properties and condition. Conventionaly rocks of this complex belong to the cemented 402 and coarse-detrital shingle with clayey and clayey-sandy fill, of different size from 2-5 to 0,3-0,5m boulders with different degree of treatment, weakly and well rounded, permeable, with good carrying capabilities. In the massif shingles can hold almost vertical slope, stable. Clays are homogenous or thin layered with impurity of sand and pelitic material, dense, partially permeable, soaking and washing out in the water environment, deformable with low carrying properties.

Geological-genetical complex of lacustrine sediments (lQ2) Upper Pleistocene-Holocene units have wide spreading within the studied area. Especially they are widely developed on the Akhaltsikhe plateau. Lacustrine sediments have local areal spreading westwards Shalosheti mountain on the Erusheti highland, also, northwards Kalem mountain within Adigeni region and in many other places within the area. Sediments of the given complex were formed in the lakes and erosional depressions with Middle and Upper Pleistocene lava flows. Thickness of this sediments, in the big lacustrine kettles (near the Akhalkalaki town), is more than 20m and in other places vary between 2-5 and 20m. Lithologically this complex is represented by clays, loams and rarely by sandy loams, which are alternate with interbeds and lenses of sand, gravel and shingle. They have horizontal bedding and very rarely slanting bedding. This sediments almost everywhere have two-bedded structure. The first layer have thickness from 0,5-4,5m to 10-12m, represented by the clays and loams and the second - by the shingles and more weakly rounded different detrital material with loamy-clayey, rarely sandy loamy fill. There are also available lenses and interbeds of sand, sandy loams, loams and clays with thickness from 0,3-1 to 2-3m. Clayey rocks are grey, dark grey and brownish. They are represented by heavy varieties. Grounds are of montmorillonitic composition, sometimes with impurity of calcite, chlorite or hydromica. Rocks are tightly plastic and plastic, soft. Main characteristics of the lacustrine-clayey grounds are given below in Table, 13.

Table, 13, Main characteristics of the lacustrine-clayey grounds (Giguashvili, 1969). Soil Water Unit Specific Porosity Plasticity Coefficient Angle of Cohesion type content volume gravity Limit of internal internal (%) weight % friction friction (MPa) gr/cm3 Clay 9.7-29.0 1.71-1.94 2.67- 33-49 21-31 0.364- 23-30 0.046- 2.75 0.601 0.063 Loam 12-36 1.45-1.86 2.67- 45-60 8-17 0.364- 18-25 0.018- 2.71 0.488 0.043

403 Clayey united rocks are waterproof or with low filtrational properties, not water- resisting, deformable. Underlying coarse-detrital grounds are friable, rarely consolidated and weakly cemented. Composed by shingle and boulders of different lava rocks (0,3-0,5m). Fill is clayey-loamy, rarely loamy-sandy loamy, often contain lenses and interbeds of sand, sandy loam and uliginous clay. Coarse-detrital grounds are permeable, easily washed out, with medium carrying properties. This layer is located under the level of ground waters. Swampy nature of the area is characterizing the complex. On separate areas turf forming process is continuing. Subsidences are rarely marked. Underground waters are located almost near the surface or at 1-3m. depth. Their mineralization is low and not more then 0,5 gr/l. Waters are hydrocarbonaceous calcic-magnesium.

Complex of the alluvial-swampy sediments (hlaQ3-4) Upper Pleistocene- Holocene units have extensive coverage on the surfaces of Akhalkalaki and Ardahani plateaus. They are also present on the south-westward areas of Akhalkalaki town, up to the state border. On this area young doleritic lava flows create closed depressions, which are filled by swampy lakes and swamps. Within Turkey the analogous closed swampy depressions are filled by rocks of the given complex and are widely spreaded along the north side of Çıldır lake. They are everywhere within the boundaries of settlements Esmepinar, Çıldır, (Zurzune), Iakinsu and Damlıca. The second region where this complex has spreading between Ardahani and Damal (where they composed of bottoms of the wide: Alabalık-su, Cenkelek-su, Büyük dere, Horasman dere, Büyükçay and river ravines) near the Damal, Avcılar, İncedere and Hanak settlements. Complex is polygenetic and composed of alluvial lacustrine and swamp sediments. Accumulation of the latters was continuing the closed and half closed depressions at first in the lacustrine reservoirs, and then in the swamps. The alluvial material came from the rivers. Lithologically the complex is represented by clays, loams, mud, turf with interbeds of gravel and sand. Their thickness near the Akhalkalaki town and Çıldır lake is more than 20m. and in the rest of the territory 5-10 and 10-20 metres. Physical-mechanical properties of clayey cemented grounds of the given complex could be similar to the first rocks layer of the complex of the lacustrine sediments. They have high natural dampness, low density, high moisture capacity, significant and uneven deformability-compressibility.

404 Commonly, the grounds of the complex belong to the group of rocks with special peculiarities. They are weak permeable, water-resisting and have low carrying properties. This and above mentioned peculiarities determine this rocks as weak grounds, unsuitable for building purposes.

Sediments of Mountain Glaciation Formation Whether Lesser Caucasus and Pontide mountainous system were subjected to Quaternary glaciation is remain debatable till today. One group of scientists positively deny possibility of Quaternary glaciation within Lesser Caucasus, what they explain by the low hypsometric location of the latter. The second group of scientists (Tsereteli, 1967; Tskhovrebashvili, 1978) on the contrary, indicate the existence of glaciation and on the concrete facts of its activity. We have had very few information about geomorphological composition and history of paleogeographic development of Quaternary glaciation on Pontides. Joint Turkish-Georgian investigations carried out 1995-1996 along the border- line, enlighten some blanks, about Quaternary glaciation of Lesser Caucasus- Pontides. It is necessary to mark that there are many problems which are to be specified and generalized. Some points are established by the joint investigations and analysis of existing materials : 1. In the studied area Quaternary glaciation had extensive coverage. It had important place in forming of modern shape of relief of the territory and in the establishment of engineering-geodynamic processes. 2. The landscape of the recent relief is well remained glacier and periglacial formations. 3. Scale and expression of the glaciers, considerable increases in the Adjara- Trialetian mountainous system from east to west, in Pontides from south-west to north-east, and in Akhalkalaki-Ardahan volcanic relief system from north to south, which must be connected with rising of atmospheric precipitations, dampness and hypsometric marks of the relief. 4. Geomorphologic nature of glacier relief indicates that here not only Vürmian, but also Rissian epoch glaciation must have taken place. Although, signs of the Middle Quaternary glaciation is weakly remained and is mapped only in the nearest ravines of the Chorokhi river basin, in state of trough shoulder-straps, located on 100-150 m. height from recent river-beds. Tsagareli (1964) and Tskhovrebashvili (1978) have described the signs of Risian glaciation, with 10 m. thick moraine sediments in the basin of the Qabliani river, near Persati place. We think, that insignificant scale of the Pre-Late Quaternary glaciation, which are remained in state of separate isolated areas, is stipulated by several circumstances: the first - hypsometric marks and warm climatic conditions of the 405 region in Late Quaternary, did not contribute to the formation of paleoglacial regime. As a proof, there are available mammalias of warm and aridic climate, studied from the lacustrine sediments of Arsiani and Akhalkalaki. The second stage is beginning in late Khazarian, during the Khvalinian century, temporary lessened volcanic activity, started rejuvenation with new power. This condition, at first contributes to the increase of air temperature. But then, volcanic dust, spreaded in atmosphere, creates reversed "thermal effect". The third stage - at the end of Khazarian and at the beginning of Khvalinian period, begins intensive orogenic movements and increase of absolutee marks of relief. (Tsereteli, 1967.). At the same time the earlier flatted surfaces and volcanic massifs were risen, which created suitable conditions for accumulation of solid atmospheric precipitations and establishment of paleogeographic regime of Late Pleistocene glaciation. The fourth stage begins with intensive activity of denudational processes because of this the most part of early glaciation (Rissian) formations were washed out by erosion and exaration of glaciers, or were fossilized under the young lava flows. 5. In the region 2 types of mountain glaciation were developed. The corrie- ravine type and the dome-shield type. Corrie-ravine type glaciers are mainly developed in the basin of the Chorokhi river, where glaciers came down from the Eastern Pontides, Karçal, Şavşat and Arsiani mountain massifs and took the upper segments of the ravines of almost every affluent, made typical trough ravines and creating the several ten meters thick sediments in the form of bottom and last moraines. The signs and sediments of Vürmian glaciation in the studied area are marked in the ravines Bagindere, Ojuirdili, Murgul and Khatila. But their morphological nature and lithological peculiarities are especially well mapped in the basin of the Meydancık dere river. It seems, the glaciers from Karçal, Şavşat and Arsiani ranges are filling the erosional kettle of the river and moving as a united body SW in the trough ravine. On the place of their activity there are the remain of ten meters thick glacial sediments (near the Veliköy, Pınarlı more than 100 m), in state of glacial hills, hillocks and dammed lakes. The classic example of the lake, dammed by moraines, is the Karagöl lake. The borders of spreading of the last moraines of the Vürmian glaciation are fixed in the Zetileti, Diobandere (Detobeni), Ilıca, Pınarlı, Çağlayan dere river ravines at the 1100-1500 m. height and on the territory of the Şavşat town. All that ravines have typical trough shape. In this ravines the remains of 3 staged moraines of the Vürmian glaciers retreat are marked. At the same time, almost in every ravine, on the 100-150m height, geomorphologically mapped Middle Quaternary (Rissian) glaciation surfaces are present in the state of separate fragments. In some of them, (Pınarlı, Veliköy, Paparte, Taşköprü, Çağlayan dere, near the Karagöl lake and e.t.c.) moraine sediments with 5-20 m thick are present. The morphological and lithofacial nature 406 of the Vürmian and Rissian glaciation is in good correlation with fluvioglacial terraces and their sediments out of the borders of trough ravines. Their morphological and lithological sections are well mapped in many places, as in lateral tributaries of the Chorokhi river as in the main ravine. The sediments and glacio- genetic relief forms of corrie ravine type Vürmian glaciation are relatively weakly developed within Adjara-Trialeti system. The cupola-shield type glaciation is characterized for the region of the Akhalkalaki-Ardahan volcanic relief. It is established, that the glacial fields are taking place mainly 2600-3050m. elevations and their radialy directed tongues coming to the edges of closed kettles of Akhalkalaki, Ardahan, Çıldır, Karaçay and may be much deeper. Their formations are covered by fluvioglacial, prolluvial and lahar type mudflow, lacustrine, river sediments. The clear confirmation of that has given by outcrope north of Hanak, along the road, which is represented in the upward section. 1. Typical lacustrine sediments, thin layered, sandy clay, with interbeds and lenses of gravelites. Their thickness correspondingly are 1-5mm and 1-4cm. In the lower part of the section they are solid enough and show well preserved the thin layering. Visible thickness is 2,5m. 2. Lacustrine, fine-grained, homogenous sand with volcanic ash, with dusty structure, not layered, solid enough, thickness is 1,5m. 3. Fluvio-glacial conglomerate, well worked out, different size round-stones with gravel and thin rubble, significantly cemented by sandy-clayey material, thickness is 1,2m. 4.Glacial boulders, medium worked out, filled by gravel sandy-loamy fraction, densely layered, cemented enough, thickness is 5m. Also, the glacial-fluvioglacial sediments in many places covering the different generation Pliocene-Pleistocene sediments and in united section are represented as Akhalkalaki-Damal formations complex. In the Ardahan-Akhalkalaki zone the Vürmian epoch glaciers are characterized by cover-shape spreading. They clearly indicate the glacial sediments and glaciogenous formes mapped on the slopes and ridges of the Arsiani, Erusheti, Çıldır, Kısır dağ, Kamer dağ, Abul-Samsari mountains. This sediments are continuing along the Murgul, Ashagi-toriskhevi, Nurandede, Kuzunliti villages, which are located along the west and north parts of the Ardahan kettle. The landscape, modified by glaciers is continuous along the plateau which is directed to the north from Ardahan-Hanak to the Erusheti range. The significant formations of the glaciers activity has been mapped on the ranges of Javakheti, Göktepe and Gukasiani.

407 The glacio-genetic formations mapped in the studied area, affirm that the glaciers (especially Vürmian epoch) had more wide spread, which are protected on the relief. In many places the trace of their existance is removed due to intensive influence of the modern exodynamic processes. By engineering-geological standpoint, the glacial sediments everywhere are built up of coarse boulders, filled by pebbly-rubbly and clayey fraction. The boulder material takes 30-40%, pebble and rubble 20-25%, gravel and average 5%. The rest is fine- grained, from them sand 10-12%, aleuritic fraction 30-36%, and clayey 42-58%, with number of plasticity between 18-27. The sediments distinguishing by enough dense structure, medium solid and medium water conducting, with relatively stable properties on the slopes (especially in the bottom and last moraines of the glaciations early stage).

The Complex Of The Fluvioglacial Sediments (fgQ2-3) is the direct continuation of the last moraine and troughs, by its lithofacial nature and engineering-geological characteristics belong to the group of the mountain glaciation formation. Fluvioglacial sediments have enough spreading in the basin of the Chorokhi river, especially in the region of Ardahan and Ahalkalaki. In the Chorokhi river basin the fluvioglacial sediments are mainly forming second and third terraces, within the intervals 30-50 and 100-150m. They are characterized by interrupted-fragmental spreading. Their morphological nature and lithofacial character give possibility to restore the unite shape of their spreading in the Chorokhi river basin. The fluvioglacial sediments are located on the erosional surface of the basic rocks and mainly remained at the stages of 30-50m. height terraces. They are especially well preserved in the Chorokhi river ravine, on the lower level of the Murgul, Şavşat and Adjaristskali rivers. Unlike of normal alluvium, they lithofacially are represented by different treated coarse pebble-rubble, which is filled and cemented by the sand and sandy-loamy fractions. The latter is represented by lenses and layers in many sections. Such kind sections are in many places in the Chorokhi river ravine, north of Artvin town, where the separate fragmental spreading of remained sediments is about 100-300 m thick. In one of this sections, near the Artvin town, on the left side of the river, in the upward section are represented: 1. Boulder-gravelly, weakly cemented material, treated with different degree, represented by granitic and volcanogenic material. They have 5-40 cm in size, filled by sand-pebble fraction about 25-30%, thickness 18m. 2. The round stones of rubble is well worked out, with participation of boulders by 5- 10%, filled by sand-gravelite fraction 20%, with participation of their lenses and interbeds, thickness 5-15m. 3. Coarse, boulder-pebble material, filled by sand-rubble, medium cemented, thickness 5m. 408 The section of such fluvioglacial sediments are dominate of the Chorokhi- Adjaristskali basins, where the pebbly-boulder material take 40-60% (from them more than 200mm is 20%), rubbly fraction is 25-40% and the rest is sand and loam. Their volumetric weight is 1,56-1,60 gr/cm3, specific weight 2,71-2,77 gr/cm3. Structure of the sediments is friable and weakly cemented, easily demolishing, but commonly takes high angle, frequently vertical, have good water conductivity and carrying capability is high.

Tectonogenetic Formation Technogenetic formation is represented by a complex of the cover rocks, which unites technogenetic sediments, created by the human’s economic activity. This sediments are developed in almost every populated areas of the both countries, in zones of large mining enterprises, along the roads and in other places of human’s intensive economic activity. This sediments are characterized by the small degree of thickness and areal spreading, different composition and properties. Varieties of the technogenetic sediments are mainly represented by the economic and building dust (rubbish), places and embankements, constructed for the purpose of roads and economic objects, terricones of quarries and mines and antiabrasian embankements, constructed along the sea coast line. Because of small area spreading, it was impossible to mark rocks of this group on the engineering- geological map. Exceptionally it is marked at terricones, located in zone of Vale coal deposit. They take about 10 hectares area and are distinguished on the map by the corresponding indexes. Near the large populated areas on the studied territory they are frequently dust- dumps, where is going gathering, processesing and burning of domestic dust and building and economic remains. This kind of dust-dump is located southwards of Batumi town on the right bank of the Chorokhi river and covers several hectares. Near the other populated areas often are available 0,5ha or less dust-dumps. This state technogenetic sediments are loose, uncemented, high porous grounds with changeable filtrational properties. Their thickness is 1-3m. Carrying capabilities of these grounds are small, but their compressibility is high. Places and embankements, constructed for the purposes of roads and economic objects, mainly take place in limited areas and are represented by the 1-5m thick clumpy-detrital and gravely-clayey concentrations, which on the grounds with capabilities of changeable carrying and filtrational. This grounds on the slopes are often stable or in condition of limited equilibrium. Creation of terricones of weak grounds and other remains are connected with large mining enterprises. Remains of this state (10-15m thick) are in areas of Vale coal deposit. There, bars and terricones are represented by the parcelled out grounds 409 of Oligocene clayey-sandy formation. Their complete disintegration to the clayey material has been under the influence of atmospheric agents and insolation. They are characterized by the weak carrying capabilities, water-resistance, easy wash out of surface and not stable slopes. Southwards of Sarp town, on the territory of Turkey, along the sea coast, clumpy-detrital material, created by the cutting off the Middle Eocene hard and half hard rocks, are used for construction of antiabrasian embankements. This material is well water conducting and of high carrying capability, stable grounds. Their thicknesses vary within 5-10m. It is necessary to mark the high effectiveness of buildings in connection with dynamic influence of waves. The territories free from the sea used for recreation zones and communications.

RECENT GEOLOGICAL PROCESSES

The whole complex of complicated physical-geographical, geological, hydrogeological and other natural conditions of the region, stipulate intensity and activity of development of the geological phenomenons and processes. Determining role in formation of the engineering-geological conditions within the studied territory, from the endogenic processes, take earliest tectonic movementy of the crust and is connected with its seismic phenomenons. From the exogenics, the leading are weathering of rocks, landslidic and other gravitational phenomenons, the wide spectrum of erosional processes, abrasion of the sea-stripe and snow-avalanches. All of this processes and phenomenons are densely connected and in many cases stipulate or fill each other. During the last years, human's economic influence on the environment takes wider part, which brought catastrophical consiquences, without the special engineering preparation. Because of this, at present, degree of human's intensive influence on the environment became a serious factor in case of estimation of engineering-geological conditions of the territory, which have also revealed on some segments of the studied territory.

Recent Tectonic Movements of the Earth Crust and Seismicity

One of the most significant factors in the formation and changes of the engineering-geological conditions of territory, is recent tectonic movement of the Earth crust. Indices of energy of the relief, continual rejuvenation of the slope profiles, changes of the erosional basis, which is connected with the intensivity and activity of exogenic geological processes, straightly depend on it 410 On the investigated territory, this movements are revealed in face of mountainous systems and dipping of intermountain tectonic depressions. According to this, elevations of Adjara-Trialeti and north-eastern lowland of the Eastern Pontides, relatively dipping lines of Tsalka-Akhaltsikhe and Akhalkalaki volcanic zone are distinguished. Zones of the elevating and dipping, from the orogenetic stage up to now, expose the intensive vertical movement. Herewith, it is noticeble circumstance, that movement is interrupted and is kept different nature. Adjara-Trialeti elevation zone, extends all over the Adjara-Imereti or Meskheti range, west half which is sharply cut by the Black Sea kettle, in Batumi areas. Amplitude of the earliest elevation of this mountainous system reaches 2-2,5 km. As a real sign of the different stages of elevations, occur main ranges and relicts of flatted surfaces, storeyly located on the slopes of their branchings. The highests of them are fixed on the ridges, on 2,5-2,7 km height, or pre-ridge parts in 2,15-2,3 km interval. They belong to Miocene age (Astakhov, 1973; Tskhovrebashvili, 1978;). Hypsometrically lower, on 900 m. absolute height also are located 4 lines of younger flatted surfaces. Zone of the Adjara-Imereti elevation, in the south is divided by the Tsalka- Akhalkalaki narrow dipping zone. Its extreme western part is Adjaristskali sublatitudinal dipping swally trough, which have different direction as the fold and wholly spread the ravine of the Adjaritskali river. Forming of the Adjaristskali dipping swally trough, as it is seen, started in Oligocene-Miocene. Westwards it dips and opens to the Black Sea, where it is covered by the widened, deepened and dippend mouth of the Chorokhi river. In the area of Goderdzi pass, the bottom of the swally trough is maximally elevated to 1,5 km. height. Eastwards, it dips again and joins the Akhaltsikhe depression. This last, remained structure occures, which is relative dipping have renewed after the gathering of Mio-Pliocene Goderdzi volcanogenic formations. In the Akhaltsikhe depression, base of Goderdzi formations lies on 1 km. absolute height in Oligocene rocks and is destroyed by them. Akhalkalaki volcanic zone extends all over Eastward territory of Goderdzi pass latitude. Within it, the Şavşat range, Erusheti mountains, Akhalkalaki and Ardahan volcanic plateaus are located. All of them were exposed to intensive influence of the earliest volcanics zone is built wholly by the Mio-Pliocene and Quaternary effusives. Taking in an account the structure of the neighboured zones and availability of the pre-Neogene rocks only in the peripherian parts of the zone, we can admit that basement of the volcanic zone effusives elevate not more then 2-2,5 km., and in some places which are dipping lower to 1,0-1,5 km. 411 We can suppose that in the late Pliocene-Quaternary period, Erusheti mountain, which has already been wholly destroyed by the sediments of the Goderdzi formation, is exposed to 1,5 km general amplitude weakly inclined arch elevation. In the west, Akhalkalaki volcanic zone, the heads of Şavşat dere river adjoins East Pontian elevation which is distinguished from the Adjara-Trialeti elevation zone by the Adjaritskali tectonic swally trough. On the vertical grow of mentioned mountain systems, points antecedent nature of the Chorokhi deep ravine, on the Borçka-Adjaritskali segment, depths of the vertical cut reach 1,5-2,0 km. On the Adjara-Trialeti elevation, flatted surfaces are located like a floors on the steps of the main ranges and their branchings. The oldest flattened surfaces are also developed on the ridges and pre-ridge parts of mountains, but interval of the height is a little bit higher and fluctuates in limits 2800-2000 m. Hypsometrally lower, on 1600-1800 m, there are biggest and sharply displayed flattened surfaces in the relief. There are located Tepebaşı, Obaköy, Çiftepınar and other villages. Lower steps are on 1200-1400 and 800-600 m heights, with the Muratlı, Cevizli, Üzümlü and Çiftehanlar villages. It is necessary to mention, that on the Chorokhi river and its right tributary Deviskel dere watershed's ridge, on 800-900 m. height is located on sublatitudinal wide flattened surface. The flattened surfaces on the north slope of Şavşat range are almost in the same intervals. It is permissible, that the age of the highest flatted surface is Miocene, and amplitude of earliest elevation could reach 2,5-2,8 km. For the Western part of the Adjara-Trialeti elevation zone, average speed rate of the vertical movement is 2 mm /year (it is measured instrumentally and calculated according the scientific generalization of seismic data). It increases to 3 mm /y in the ridge part of the range. Adjaristskali swally trough dips with 1,3 mm /y. average speed, and to the mouth of. Chorokhi river decreases to 0.8 mm /y. Southwards, elevation of the Gonio-Sarp segment and the rest eastern part of Adjara is uplifting with 2 mm /y. in average speed rate. On the maritime slope, In Turkey, sharply displayed flattened surfaces, stepped locations of the marine terraces, peculiarities of beach stripes, multiple abrasian of cliffs and columns along the coastline indicate the positive nature of the land's recent vertical movement. The same nature has been seen in the North-East edge of the Eastern Pontides. Its could be about 2-4 mm /y. As it is known, earliest movements of the Earth crust are straightly connected with earthquakes, which provoke establishment of massive recent exogenic processes or their activation. Importance of seismic swinging movement, for mountainous countries like Georgia and Turkey, particularly increases and often keeps nature of considerable engineering-geological factors. There are fixed almost every powerfull

412 earthquakes in the investigated region, as with transit, as with local epicentres. According to territory, they have different seismicity. According to seismic zonation, Akhalkalaki zone, which extends all over Erusheti mountains, Ardahan and Çıldır side, belongs to 8 bal* zone and Akhaltsikhe depression to 7 bal in scale of earthquake intensity of Merkally. The absolutely opposite situation is in the maritime region. In the Western part of the Adjara-Trialeti elevation zone, as in limits of North-East ending of Eastern Pontides, medium and powerfull earthquakes almost are not fixed. Significant seismic activities keep transit nature here. Except in Batumi region, where west of the Adjara-Trialeti folded system ends, it is sharply cut by the Black Sea kettle. According to last 20-30 year observations, this zone belongs to 7 bal. The rest part of investigated territory in limits of Georgia and Turkey is in the 6 bal zone.

Recent Exogenetic Geological Processes

Recent exogenetic geological processes which often takes catastrophic nature are particularly widely spreaded on the studied territory,. Especially gravitational and erosional-abrasional processes, mudflows, snow-avalanches are distinguished. This processes damage economic units, reduce productivity of the land, provoke deformation and result in the destruction of engineering buildings.

Dynamics of The Sea Coastline Almost 44 km. segment of the sea coastline on the studied territory, occures in the hardly changeable morpho-density system. Engineering-geological conditions stipulate the setting in the densely populated and intensively assimilated sea coast. Sea coastline has a assymmetric arch form, directed from the south-west to the north-east and is complicated by the invaded into the sea ledges of the Chorokhi river, Mtsvane Kontskhi (Green Cape) and Tsikhisdziri. Foreseening the geological, geomorphological, hidrological, lythodynamical and other conditions, It is divided into: Tsikhisdziri, Batumi-Chorokhi and Kandildere and Kemalpaşa main regions, united into Chorokhi river lithodynamic system. Tsikhidziri region, or structural block, which uplifts with 2 mm /y. average speed rate, is located on the extreme North part of the sea coast. Characteristic sign is, partly invaded in the sea , Tsikhisdziri and Mtsvane Kontskhi (Green Cape) ledges with almost vertical high cliffs, which are interruptelly extending along the shore, in alternation with narrow beach stripes. Chakvi beach stripe is located between these two capes. Both of this capes are abrasian, but speed 413 of their wash out is insignificant, because of high density and stability of Middle Eocene volcanogenic hard rocks. At the foot of maritime steps, abrasional, moved in shelves, are changed by the local ledges, which from South are filled by the small beach fragments, about 10 m. width. Between the capes, on 2,5 km length, continously comes 35-50 m width beach stripe. Its alimentation with rubbly-pebbly material is made by the Chakvistskali solid sediments. Wholly the beach is abrasional, it is changing by the short time balanced state on separate segments. Between capes, beach is strengthened by the antiwave walls and sinked concrete blocks. Batumi-Chorokhi (Coruh) region, which is exposed along all over Kakhaberi lowland and Chorokhi river delta, which have been formed by new Euxinic regression. Redeepening of the Chorokhi river and fecundation of underwater canyons is connected with this. The different nature of the late stage tectonic movement and continous powerfull flow of the Chorokhi solid sediments, form the lowland and delta with present faces. Northwards, from the mouth of the Chorokhi, to the Burun-Tabu cape, width of the coastline is sharply changeable. Catastrophical washing outs are changed by the significant grow of the shore. Comparing the coastlines of 1834 and 1974, shows, that in this period sea has washed out 500 m. of the shore. It is directly connected with drying of the Chorokhi delta branch, Mejinistskali river, in the begining of the last century. A small changes of natural and human-made factors, have a considerable role in the preservation of stability of this segment. Sharp shortening of the solid and liquid sediments of the Chorokhi river and the destruction of the hydrodynamical regime of the coastline, will inevitable provoke catastrophical washings out of the shore in the area of Batumi town. Opposite the Chorokhi river mouth, at the bottom of the sea, Chorokhi canyon, which is composed by the 4 main branches and 21 branchings are developed. With deepening, this branchings join each other and at the edge of the shelf we have 4 branches of the canyon. From the mouth of the Chorokhi river, southwards of Gonio village, along the whole length of the shore, is 100 m. width beach stripe. Southwards it narrows and at the Kvariati village it dissapears. Beach is built by the well rounded rubbly-shingle, with gravely and some sandy fill. Coastline is in a zone of relatively restricted development of the Chorokhi solid sediments. By the regime observations, here is mentioned insignificant, but the beach growth is stable (1 m/y). On the local segments, particularly southwards of the Gonio village mentioned washing outs are weak. 414 Northwards, from the Batumi Port to the Mtsvane Kontskhi (Green Cape), along the shore comes the narrow beach (5-25 m. width). The solid beachmaker material of the Chorokhi could not reach this segment and the shore is exposed to the intensive abrasion. Beachmaker material of the small rivers are hardly enough to keep narrow (25 m) beaches to the mouths. By the washing, width of the beaches is shortening to the 10 m. and on the some segments they are wholly destroyed. On the whole 6 km. length, coastline is strenghtened by the antiwave reflecting walls, which are not effective enough. Kandildere-Kemalpaşa region spreads all over extreme south part of the territory, in the border stripe between Turkey and Georgia. Region is connected with the south wing of Adjaristskali syncline, which is cut by the diametrical fault. Surface of the fault appears like a high wall along the road, on the Kandildere-Sarp segment. Southwards, some part of it is disguised and subsided. The rest part is exposed because of the uplift, and the sea part is subsiding. The original face of the environment has hardly changed along the whole length of the coastline. Along the high terrains and maritime cliffs are organized cut shelves and man-made embankments of blocks. There is constructed seaside mainroad. Exceptional are shores in the limits of Sarp and Kemalpaşa, where narrow ravines of the small rivers are open to the sea. On their borders narrow beaches, which are under the permanent influence of abrasion are established. Rest of all segments of the shore are abrasional too. On these segments man- made huge blocks of hard rocks are used to create a conducting and as a preserving embankments. The high stability of hard rocks and constructional features of the embankments, give them a nature of effective preserving buildings against the abrasion.

Erosion On the investigated territory, almost everywhere, wide spectrum of erosional processes is widely spreaded. Intensity of their distribution and variety depends on the natural-landscape zones, peculiarities of the relief, geological structure of the substratum and the degree of the economic mastering of the territory. On the most part of the territory, high energy potential of the relief, regime of the atmospheric precipitations, high tectonic destruction of basic rocks, peculiarities of rock composition, weak stability against washing of cover rocks, stipulate active distribution-revealing of the all forms of water erosion . Herewith, vertical zonation makes significant corrections in the developments of this or that form of erosion. At the seaside, in Chakvi, Kobuleti, Batumi-Gonio and Kemalpaşa areas and on the Akhalkalaki plateau, there are plane reliefs (inclination 30) and fewly inclined (3-50) surfaces, in which, rivers have sharply displayed side erosional effects. Inclination of 415 the river beds is not more the 10. With special intensity, this processes are in the limits of Kura and Chorokhi rivers, where after every inundation is causing the wash out of existing accumulative forms in the river bed, creating new forms, changing the directions of flows and forming of new meandrine ancones. The limitation of hilly zone of seaside lowlands, where it developed the crust of lateritic weathering of Middle Eocene tuffs and alluvial-talus cover rocks, is mastered very intensively in agricultural purpose, by tea and citrus plantations. Big inclination of slopes, surfaces of smooth and rounded off ridges stipulate the development of plane erosion. Along the sea coast line the creation of ravines is marked, but the track of active erosion is not visible, because the ravines are covered by plants. At the same time, in the places, where the plant cover is destroyed by human activity, is going the formation of ravines and cut of slopes. Speed of cutting depth on the such areas is from 1 to 15 cm annually. In the ravines of the rivers Adjaristskali, Chorokhi, Machakhela, Şartul dere and on the slopes of Şavşat, Ciha dağ, Balıklıdağ and Karçal ranges, at the erosional- denudational conditions, very separated relief is widely developed the plane washing out and linear erosion. Along the main rivers, at the inclination of bottoms from 20 to 50 is visible the alternation of accumulative and erosional areas with show of lateral and river bed erosions. Along the lateral tributaries, where inclination is 5-110, river bed erosion is seen everywhere.The banks, which are mainly built by alluvial and alluvial-talus formations,by the influence of lateral erosion are retreat annually from 0,5-0,7 to 2,5 m. Forming of rivers in this zone, is shown down and exists only on the intensively assimilated areas. Speed of growing in length of the ravines, which are developed in the loams of elluvial-talus genesis, is 0,6-1,8 m. annually and the river bed erosion at the same time is from 4-7 cm to 22 cm. It is necessary to mark that the river bed erosion stops in the old ravines and only goes on in the lengthening of by 0,17-0,33 m annual. Coefficient of the horizontal separation of the territory is 4,5 km /km2. The main rivers are creating narrow, deep cutting ravines, with inclined slopes. Practically, after every inundation is going the rejuvenation of river bed and whole change of accumulative forms. The speed of washing out of the first above fluvial terrace is 0,8- 1,2 m/year. The lateral tributaries of the main rivers, with the bottom of inclination of 11-260, are intensivelly cutting the basement rocks. Along the whole length of the main rivers and their tributaries rapids and waterfalls are developed. Formation of the ravines in this zone is developing quite intensively. Coefficient of formation of the ravines vary in wide limits, from 0,12 to 5,35 km/km2. They are 416 lengthening by speed 0,1-0,8 m/y, on the landslidic areas - 1,0-1,25m. Parts of young elevation of ravines, which are characterized by highly inclined bottoms, cut in the boulder weathering zone of basement rocks, and dangerous in case of mudflows. In Alpine zones of Karçal, Arsiani ranges and Erusheti mountains, in the Chorokhi river ravine, up to Artvin and in the separate segments of Şartuldere canyon, plant cover is absent or is developed very rarely. In this places, soil layer on the surface outcrop the lower zones of the crust of weathering of basic rocks is wholly washed out. It needs to be marked separatelly, the erosional processes within the ravine of the Murgul dere. The scatter of sulphur and other elements is connected with work of mining dressing company and treatment of Murgul deposit. In the ravines were formed acting acid environment on the nature, which causes destruction of plants on the slopes and the whole outcroping of superficial rocks, directly connected intensive development of erosional processes. In many areas, soil and upper horizons of crust of weathering are washed out. Generally, in the ravine, very heavy geological situation is formed.

Landslides, Taluses and Rock-Avalanches Geological, hydrogeological, climatic and geomorphological peculiarities stipulate the great deal of landslidic processes on the studied territory, which cause with damage to both countries. At the same time, their distribution on the Turkish- Georgian borderline is characterized by high contrast. Landslides usually damage the slopes of river ravines in the central and west parts of territory, but in east part, they do not appear anyway. Landslides differ from each other by genesis, sizes, depth, character of movement, degree of activity and other parametres. Especially they are widespread and frequency ravines of the Adjaristskali, Chorokhi rivers, Şartul dere, Murgul, Potskhovi and Kura, and the mostly in middle and high mountainous zones. Usually landslidic bodies envelop lower parts of the slopes or they are in the old leveled off surfaces. Numerous landslides are developed in the seaside lateritic weathering line. Their peculiarities are expressed by the high quantitative index of small areal spreading and depth of landslides. The landslides with areal character usually are in Adjara, Akhaltsikhe kettle, near Aspindza, Şavşat and the Potskhovi river ravines. Coefficient of the areal damage here, vary from 0,1 to 0,5 and in other ravines (Gordjomi, Potskhovi, right slope of Murgul) from 0,7 to 0,9. Very small quantity of landslides are northwards from Borçka, in Cihala çay, Cevizli dere, Deviskel dere and Araklı dere river ravines. The little number of landslides take place in insignificant areas on this part of territory.

417 Landslides are not almost appeared in Erusheti highland, near Akhalkalaki and Ardahan plateaus. Other landslidic deformations of covering rocks in deep canyon- shaped ravines have local character. It is necessary to mark that, within the studied territory in mountainous Adjara, Şavşat, near Aspindza and Potskhovi, the gigantic landslidic bodies are fixed. Their sizes are from one to several km2, and depth are several metres, in some cases hundreds of metres. Such kind landslides are widely spreaded in Şavşat and Posof. As it is known, there are several classification of landslides, based on different principles. According to schemes compiled from engineering-geological investigations carried out during last ten years in Georgia, the classes of the landslides are distinguished according to mechanism of movement and the landslide types - according to flooding degree of slopes. There are foreseen the morphometric parametres of landslides. For the project of study of Turkish-Georgian borderline. It was specially worked out the scheme of landslides classification which is mainly based on above mentioned principles and foreseening the main cases of landslides occurrence. Following from above mentioned, all of landslides are united in two groups: 1.Consistencial (climatogenetic) and landslides connected with changes of erosional basis. 2. Tectonoseismogenic landslides. According to mechanism of movement, in borderline, there are sliding, plastic, rocky and complicated landslides. To the first of landslides which occurrence is connected with recent base level of erosion and to the second - landslides, their development is connected with other early state of erosional basis. The dynamic conditions cause activity or stop landslides. The active landslides loose their balance just once per year. The stables are - which have whole balance and to abolish it, they need new factors. Study of landslides developed in borderline shows that the first group - consistencial landslides are connected only with distinct natural landscape zones and geological-genetical complexes of rocks. Development of landslides of the second group is stipulated by tectonicaly strong dislocated zones in conditions of deep separation of the relief. According to the spreading character, from the landslides of first group we can distinguish : 1. Landslides, which are connected with upper parts of slopes of the ravines and with old leveled-off surfaces. Such kind of landslides are leading to the forming of the climatic and hydrogeological factors. 2. Landslides, which are developed at the foot of slopes and are connected with erosional processes. 418 3. Landslidic mud-streams and landslides,with small sizes and capacity. Occure or active under the influence of climatic conditions. 4. Rock-fall type landslides, which is determined with natural factors and human activity. Landslides, which are connected with upper parts of ravine slopes and old leveled off surfaces are widely spreaded in Shuakhevi and Khulo regions, relatively less in Adigeni and Aspindza regions. In Turkey such kind of landslides are near the Tepebaşı, Çengel, Çağlayan, Obaköy, westwards Zorlu village, northwards Şavşat, on the east slopes of Karçal mountains. Landslides of this group are characterized by large spreading and are connected with old leveled off surfaces or with upper parts of slopes almost everywhere. Surfaces have the shape of sharply cutt off-separated hilly lowland with erosional and landslidic form of relief. Wide spreading of these processes indicates on begining of following cycle of these development surfaces. Geologically, this surfaces are very interesting, Because they are intensively used by village population and damaged by landslide-erosional processes, especially upper and middle height surfaces. The main cause of activity and occurrence of the landslides is the oversaturation of covering rocks by the infiltrated and underground waters. Change of hydrogeological conditions is straightly connected with climatic peculiarities. According to activity, there are more active, rarely stoped landslides, with separate active areas. The activity of landslides is seasonal and is connected with maximum atmospheric precipitations and snow melting. The landslides are maximally active at the end of winter and during spring. With lower parts of Shuakhevi, Khulo, Chobiskhevi and Tepebaşı landslides are connected the alimentation areas of mud-flows. Such kinds of landslides give the begining to development of different processes. Except this landslides, in the separate parts of slopes or on the bordering slopes of level off surfaces, are the small landslides and mud-streams. Their areas are 0,5-1,0 hectare and the depth is 2-2,5 m. The factors which cause such kind of landslides, are (except above mentioned factors) the erosional and artificial cut off the slopes, cut down of trees and using of slopes for agricultural purpose without their preparation and without carrying out of protecting arrangements. Landslides, which are developed at the basement of slopes and which are connected with erosional processes, mainly are in Khelvachauri, Khulo, Adigeni and Aspindza regions. Their base lines are always connected with the Adjaristskali, Kvabliani, Potskhovi, Kura rivers and their tributaries. In Turkey, such kinds of landslides are mostly developed along the right slope of the Murgul dere river, from 419 Göktaş to Erenköy, on the left bank of Şartul dere, near Bağlıca, Çiftehanlar, Şavşat, Kocabey and Kirazlı, along the right tributeries of Şartul dere, near the Cevizli, Veliköy and Pınarlı. The most of the landslides are sliding and the rest-plastic. Areas of landslides in Georgia are 10-12 hectares with average depth 6-7 m. In Turkey areas of separate landslides are 5-8 times more and the depth is doubling. Almost everywhere, landslides keep activity, especially which has base line under the continuous influence of the erosion. Activity of the landslides coincides with periods after spring and autumn. Activity of the stopped landslides is connected with sharp changes of the natural conditions, with increase of dampness and with erosional cut of the slope. With these main factors are connected the development of new landslidic deformations. Landslidic mud-streams and the landslides, with small sizes and capacity, which are occured and activated by the influence of climatic conditions, are only in sea-side, from Bobokvati to Kemalpaşa. It is directly connected with lateritic crust of wathering and eluvial-talus formations. The character of distribution of landslidic deformations and their activity are almost similar. The quantitative indexes in Georgia are a bit more than in Turkey. The coefficient of the areal damage, for such landslides is 0,01-0,1 and the qualitative coefficient of damage - 8-10. At the period of extremal activity of landslides, the latter coefficient could come up to 40-50. The movement of weathered rocks is going on the slope, at the same time with increasing of dampness of lateritizated rocks, when rocks can not advance filtration of atmospheric precipitations and maximum saturation along the whole profile. By the influence of hydrodynamic pressure and gravity appears the first deformation, which is forming as landslidic mud-streams. Processes are quick and balance established during 1-2 day. Rarely this period cover several months or years. Rock-avalanche type landslides, in which creation determining is together with natural factors, human economic activity, are mostly developed in mountainous regions and are connected with rocky slopes of steeply dipping or canyonlike gorges, where often are built road communications. Landslides of this type, are fixed in Keda, Khulo and Aspindza areas, separate landslades - in Şavşat and in the Kura ravine near the Kurtkale village. Rock-avalanche type landslides are in limits of 2-5 hectares, rarely reach 5-10 h, in separate cases they took about 0,1-0,5 km area. Thickness from 2 to 5-10 m. The second main group of landslidic processes is seismo-tectonogenic landslides. Their first different sign is big and gigantic sizes. Rarely they are 0,5-1,0 km. Mainly their size is 2-5 km and in separate cases more. Their thickness fluctuates in a large limits, from several tens to several hundreds of meters. In every cases on their surfaces are located one or more populated areas. This kind landslide we meet in 420 high mountainous Adjara and in narrow Kura river ravine, especially on the Turkey border line. In the Chorokhi river ravine, on the surface of the seismotectonogenetic landslide is located Zorlu village; in the Uraveli ravine - Damri; in the Şartul dere basin- Seval, Üzümlü, Dutlu, Obaköy, Veliköy, Cevizli-Ciritdüzü, Pınarlı-Meydan, Meydancık; in the Potskhovi river basin - Süngülü, Kolköy, Kaleönü, Baykent and Aşıkzülali. Seismo-tectonogenic landslides are developed almost in the every geological- genetical complexes. They are in Cretaceous, Middle and Upper Eocene, Oligocene and Upper Miocene-Lower Pliocene rocks, which have built the steep slopes of the deep ravines in the places of the development of landslides. It is presumable that in conditions of the high energy of the relief and rocks high destruction, only seismic pushes can give the begining to the gigantic landslides formation. Between the seismotectonogenic landslides, which are widely spreaded in the Artvin-Şavşat-Posof stripe, foreseening the sizes, degree of mastering, geological future and other natural conditions, is characterize Meydancık town landslides, it's brief characteristic is given below. In limits of Meydancık town, on the Meydancık dere right bank, seismotectonogenic landslide is developed. Ravine of the river is hardly separated by the side tributaries, depth of the vertical cut is 600-800m. Ravine is symmetric, with 30-350 inclinated slopes. Bottom of the ravine is on the 1200-1250 m. absolute height, it is narrow, filled by the alluvial-fluvio-glacial sediments, represented by the well rounded clumpy-river gravely material. On the right slope, in limits 2000-1600 m, is well expressed the landslidic tear cirque-like surface, which’s average inclination is 30-320. Between 1600-1200 absolute heights is located creeped landslidic body. It occures the whole steppy surface. Surfaces of tear cirque and step are joined by the 20-25 a bit convexed slope, which occure after landslidic step slided body. Landslidic step is straight, a bit inclined to the back, weakly separated surface. From the board of the surface to the Meydancık dere steeply dips 80-90 m. height scarp. In limits of the step and especially its scarp, in many places are shown underground water upflows. Inclination of the surface and humidity of destroyed grounds stipulate the secondary landslides on the surface. All of secondary landslides are active. Landslidic step is composed by the clumpy-road material of Cretaceous volcanogenic formation, with clay and clayey fill. Presumable thickness of gathered material is 100-120 m. Meydancık dere river intensively washes landslidic body, but gathered there clumpy material preserves the bank from the negative influence of the erosion.

421 Westwards the village, with the Cretaceous volcanogenics, is fallen down the whole block of Senonian organogenic limestone, which is stably set in the bottom of the ravine. Block is jointed, but undestroyed. It’s volume is about 100-125 000 m3. Wholly, as a limestone block, as a landslidic step are stable. There are no signs of the both bodies movement in the village limits, except the secondary landslides, developed on the scarp surface. In the nearest future, some of houses could get in the dangerous zone of their influence. Thus, reconstruction-mastering of the most part of the village is possible after the special investigations and only after the engineering preparation of the territory. On the investigated territory, taluses and rock-avalanches are widely spreaded. Mostly they are developed in high mountainous zones. In limits of development of lateritic weathering crust and Oligocene clay-sandy formation, this processes are not available. Taluses and rock avalanches are connected to the high steeply dipping and outcropped slopes or rocky walls, along the Chorokhi, Adjaristskali, Potskhovi, Kura river ravines and their tributaries. In limits of Akhalkalaki, Ardahan plateaus and Erusheti mountains, these kinds of gravitational processes are available on the steep slopes of canyon like ravines and low hills. In the zone of Jurassic-Cretaceous granitoids and other crystalline rocks, clayey shales, Cretaceous volcanic formations and Middle Eocene layered tuffs development, which spreads all over Chorokhi and Şartul dere river ravines, taluses almost continously comes along the steep slopes, built by these rocks, on the both sides of the ravine. Taluses are rarely available in the Middle Eocene Nagvarevi and Chidila suites, which are lessly exposed to weathering and processes of denudation. They are characterized with wide spread of the block zone of the crust of weathering. Numerous taluses on the West slope of Arsiani range, on the North periphery of Erusheti mountains and on the steeply dipping slopes of the narrow canyonlike ravines of Ardahan plateau, are connected with Goderdzi formation rocks. In all cases clumpy material with road material and sand predominates taluses. Taluses are active and are in the development stage, because the alimentation areas continously supply them with the solid detrital material transport. On the periphery of Akhalkalaki plateau, on the slopes of Kura and Paravani rivers, numerous taluses create colluvial-trains at the bottoms of the slopes. Areas of their alimentation are connected with doleritic lava flows and basaltic covers, which supply taluses with large quantity of detrital material as a result of intensive physical weathering. Thickness of this gathered material reaches to 10-20 m, in some cases more.

422 Next to the taluses, there are widely spreaded rock-avalanches too. They are available in almost every geological-genetical complexes, except Oligocene clayey- sandy formation. Especially they are spreaded widely in the middle and upper levels of Middle Eocene Goderdzi effusives, Akhalkalaki lava flows and basaltic covers development. The maximum concentration of rock-avalanches is on the west slope of Arsiani range and north slopes of Erusheti mountains, along the perimeters of Akhalkalaki and Ardahan plateaus, on the steep slopes of the Kura river and its tributaries. In this case, rock-avalanches are connected with effusive rocks of the Goderdzi formations and andesitic-basaltic rocks of Akhalkalaki formations. Volume of the rock-avalanches change in large limits, similar as a thickness of gathered material. In the Kura ravine, next to the one and ten thousands of m3 of fallen colluvion, there are hundreds of millions of m3 volume rock-avalanches (Tmogvi, Bertakana, Vardzia and e.t.c.), where with the clumpy- road material we have a huge blocks and separate benches of the basement rocks. Thickness of the colluvial material in Kura ravine, along the Arsiani range and in the limits of Erusheti mountains, is usually 10-20 m and some times more. Old, new and recent rock-avalanches, are connected at first, with the fractures of relaxation and break off, created on the steep slopes of the young ravines and by intensive weathering of rocks and second - with the seismic activity potential of the region.

Figure, 5, Aspindza region, rock-avalanche of Bertakana. 423 This kind aertical, opened and deep cleft systems now are marked along the ravines of the Kura river and its tributaries, in the limits of Akhalkalaki and Ardahan plateaus and Erusheti mountains. Similar condition is along the young ravines of the Chorokhi, Adjaristskali, Şavşat dere basins. Processes of the creation-development of the clefts go very slowly, but continously. Small volume rock-avalanches, falling out of separate blocks and other like processes, are often connected with the pre-road steep slopes. All of this phenomenons are created under the influence of the increased hydrodynamical push of the underground waters in the clumpy and clumpy-road material zones of the jointing, filled by the alluvial clays crust of weathering. Because of this, sharp rising of this kind of gravitational processes are marked after the intensive rains.

Mudflows In spite of less development of the mudflows, in the investigated territory, they still are dangerous natural phenomenons. More than half of the fixed mudflow phenomenons here are the real threat to the economic objects. At the same time, there is unequal development of their distribution on the territory. Mudflows are absent on the main part of the Erusheti mountains, except it’s north periphery, in the limits of Akhalkalaki and Ardahan plateaus; exception is the west bank of Çıldır lake, where on the Golebakan and Sazlısu areas proluvial material, evacuated by the gourges are revealed. The main part of mudflows are in highmountainous stripe and in the limits of Akhaltsikhe depression. Except conditions of the geographical-landscape zones, in the distribution of the mudflows, the nature of development of the geological-genetical complex has considerable meaning. Main part of the mudflow hearts is connected with Cretaceous, Middle and Upper Eocene volcanogens, Upper Eocene and Oligocene clayey- sandstone formation and Goderdzi effusives. Distribution of the mudflow phenomenons, on the investigated territory, contribute, densly connected, natural and hand-made factors. Mainly high energy erosional-denudational relief with big difference of absolutee heights, developed on the big part of the territory; high index of the horizontal separation (2-5 km/km2) and big depth of the vertical separation (1500 m); intensive weathering of rocks and wide spread of recent processes, which gather large quantity of easily washable loose rocks on the slopes; intensive tectonic destruction, which stipulates weathering of rocks; plenty of atmospheric precipitations and intensive rains in the warm part of the year; changeable and unstable regime of the rivers, sharp changes of the temperature; human economic activity, cutting down forests etc. In the seaside, hilly-knolly stripe from Kobuleti to Kemalpaşa the danger of mudflows is less. 424

Fig, 6. Debris cone of the waterstone mudflow, formed in Paleogene volcanogenic- sedimentary formation, occured in 1968 around Qedlebi village of Khulo district.

Intensive rains create mudflow forming and the frequency is one in 5-10 years. Exception is mudflow ravine of the Korolistskali river, located in high mountainous zone. Heart of erosional-gravitational alimentation, supplies the mudflow with plenty of coarse detrital clumpy material, which transportation is easy to the flow, because of high inclination. After coming out on the seaside plane, intensive relaxation of the mudflows begins. Because of this, almost reached to the coast, transit accumulation zone is overloaded by the clumpy road materials. Hypsometrically upper, in mountainous zone, in the ravines of Adjaristskali, Chorokhi rivers and their tributaries heads, on the eastern slopes of the Lazistan range ending and western slopes of the Karçal range, the most active are the mudflowous rivers, which mudflow alimentation areas, located in their heads, are connected with Cretaceous and Middle Eocene volcanogens. According to the established data, transformation of mudflows goes in every 2-3 years. Volume of the one time brought material is not more then 10-20 thousand m3 . With this material, separately located small and middle debris cones formed. Parts of the solid material stay in zone of transit accumulation in face of terrace steps.

425 In eastern part of Adjara on the east slope of Karçal range and in Şavşat, mudflows are widely spreaded in the middle and high mountainous zones. Their alimentation areas are mostly connected with Cretaceous, Middle and Upper Eocene and Oligocene volcanogenic formations. Mainly, mudflows, developed there are medium activity and in the Adjaristskali river basin, it is several times more than in Şartul dere river basin. Among the mudflows, predominate waterstone flows. Erosional-gravitational type mudflow hearts are characterized by the fast forming of the flow and relaxation. What about landslidic gravitational type heart mudflows. It is distinguished with pulsivity. Volume of the one time brought material is several thousands of cubic- meters. Permanently new face of mudflow creation in all length, absence of the plant cover in zones of formation, transit and accumulation and natural observations, give us possibility to conclude that transformation of mudflows, here goes in every 1-2 year. In high mountainous zone, the most parts of mudflows are fixed. Area of their alimentation, except complexes of basement rocks above mentioned are connected also with easily destructed and wide spreading of unstable lithological changes on the north slopes of Arsiani and Erusheti mountains, especial mudflows of the Skhalta and Potskhovi rivers. In both cases, alimentation areas are connected with the Goderdzi formation rocks, located in the highmountainous zones with no forest and represented by the effusive tuffs, weakly cemented tuff-conglomerates, coloured clays and argillizated tuffs. Big quantity of as a coarse detrital as fine dispersional material is permanently in the erosional-gravitational type hearts with a sufficiently large area (0,8-0,9 km2). They are composed of several separate water-gathering cirques like basins. Because of this in both cases, forming of mudflows depends only on the quantitative indice of the liquid phase, created as a result of intensive atmospheric precipitations and snow melting. Usually, here one or two powerfull mudflows can form. Less and insignificant efflux of the prolluvion here, is marked after every rain. Both of mudflows are dangerous to the population of the village and objects of economic activity. Except this, we must mention mudflows of the technical nature, connected with mining of Murgul polymetallic deposit. Along the Murgul dere bed, with alluvial material, gathers solid detrital material, treated by the mining-dressing complex and therewith flows washing liquid. Because of this, water flow, enreached by the fine disperced fraction, gets the face of sticky grey liquid. In case inundation with the reaching of limit parameters of the quantitative and qualitative indices of the liquid phase, mudflow begins to move along the stream. With the decrease of this parameters, solid phase settles. So, the zones of the mudflow forming, transition and 426 accumulation coincide each other. Because of this, from the mining-dressing complex, to the Murgul dere mouth, river-bed is wholly filled by the mixture of alluvial and tectonogenic mudflows. On the same segment the right bank of the river is wholly landslidic. Snow Avalanches Almost on the half of investigated territory the landscape-climatic conditions contribute to the wide spread of snow avalanches. In the seaside stripe, low mountainous zone, Akhaltsikhe depression and snow avalanches do not exist within Akhalkalaki and Ardahan plateaus. Instead of this, they are frequent in the mountainous and high mountainous zones. Widely the snow avalanches are developed in the high mountainous parts of Meskheti, Şavşat, Arsiani and Karçal ranges, on the slopes of Adjaristskali, Chorokhi rivers, and Şartul dere river basins. Existance of level off surfaces weakens the danger of the snow avalanches. There is the catastrophic danger of the snow avalanches in ravines of Nagvarevistskali, Chirukhistskali and Skhalta rivers. The peculiarities and frequency of the snow avalanches spread is closely connected with climatic and morphological conditions of the region. Investigated territory is quite humid and is characterized by a big quantity of snow. Height of snow cover could reach 1m, in Khulo - 2,6 m and in Goderdzi pass - 2,92 meters. Critical height of snow cover, when the stability of it is abolished, is 154 cm, and for Goderdzi pass it is 214 cm. The development of snow avalanches and their frequency here, is connected with adding of new snow. By the observations and data of many years, is established, that in the dangerous areas of the studied territories could be form: snow avalanches (from newly come snow and snow-storms); old wet snow avalanches; snow-storm avalanches; water-snow streams. The forming of snow avalanches is going from November to May and the catastrophic avalanches, as a rule, occure in February-March. The synchronous snow avalanches of new snow and snow-storm are the most dangerous and widespread. Value of such snow avalanches is small, but quantitative indice is about 6-11 on the 1 km length ravine. The snow avalanches of new snow, which are forming near ridge parts of the ranges are flowing on 3-4 km and have value 1 mln m3. The second spreaded group is the snow avalanches of old wet snow. They have big value and high damaging power. Their forming continues in spring, at the snow melting. The danger reducing, because places of their forming are known beforehand. Except this, the forming of snow avalanches goes in places, which are covered by forests, by the sliding of snow cover between trees. So, the whole territory,

427 begining from the Chorokhi river to Arsiani range are distinguished by significant danger in case of snow avalanches.

Stone Streams and Cryptogenetic Processes Stone streams and cryptogenetic processes are often within Akhalkalaki and Ardahani plateaus, on the slopes of Arsiani, Karçal and Erusheti mountains, in the high mountainous Alpine zone. The main motive power of this processes is low temperature and high temperatural gradient, which is characterizing feature for this regions of the investigated territory. Stone streams are mainly observed on the slopes of elevations, within Akhalkalaki and Ardahan plateaus, the Mrakvali, Göktepe, Akbaba ranges, eastwards Çıldır lake and northern termination of Çıldır range. Development of such kind processes is stipulated by its geological structure, geomorphological and climatic conditions. The spreading of stone streams is connected with andesitic-basaltic lava covers and doleritic flows of Goderdzi and Akhalkalaki formations. Solid coarse detrital accumulations (about 1,2-1,8 m.) of stone streams mainly have frontal character, rarely are elongated separate flows. In some cases they take the whole surface of the slope. The stone streams developed on the steep and sloppy slopes. Inclination of slopes has not a big influence on their intensity and spread, but most of them are connected with slopes with 8-120 inclination. Movement of the stone streams is caused by changes of boulder's volume in conditions of continual influence of gravity because of temperatural changes during 24 hours. So, movement of stone streams is continuous but very slows down and unnoticed. Under the lower layer of stone streams, fine disperced fill helps increasing of speed of the stone streams movement. On the separated surfaces, stone streams concentrates and creates flows of hard coarse detrital material. In the frontal parts this flows are characterized by forming of radial cones, because of different speeds of flows. These flows and stone rivers are in the zones of stone streams spreading or on the surfaces of colluvial material, which is accumulated at the bottom of slopes. Solifluction phenomenon is developed on the Shavshati, Arsiani and partly Karçal ranges, on the elevations of Akhalkalaki-Ardahan plateaus and on the Erusheti mountains, in places, where surfaces are covered by fine dispersed rocks. Mainly this processes are developed on the slopes with inclination 5-100. Solifluction run-offs create the separate niches of break away, also the elongated form and 0,4-0,6 m height stages (from slided, accumulated masses) with rounded forms, which have the precise or zigzag united fronts at the bottom of the slopes. Solifluction processes envelopes whole slopes or part of them. Often these 428 processes are at the lower parts of slopes, where is the opportunity of accumulation of fine dispersed material and their saturation by superficial and underground waters. Solifluctional bar with 1-1,2 m height, which also is the lower border of development of processes is also present. The Karçal range, Akhalkalaki and Ardahan plateaus are developed the forms (different size corries, freezing terraces e.t.c.) by influence of low temperatures and glaciers. Their detailed studies should be continued and should be carried out during future engineering-geological works.

Bog Up Within Akhalkalaki and Ardahan mountainous plateaus on the Arsiani and Erusheti ranges, arround the Çıldır, Hozapine-Aktaş gölü and other smaller lakes, also within distribution of lakustrine sediments are developed the swamps. In this regions formation of swamps is caused by the covering of open reservoirs with plants. Then, because of accumulation of turf, silt, sandy-clayey interbeds and other swampy sediments, the reservior is thinned out and occures swamp. The filling processes is finished by forming of meadows with high humidity. the examples of such meadows are developed between Kurtkale and Binbaşak villages. So, according to the stages of development there are many types of swamps. The main plants, which are forming swamps and turf, are the reed and sedge, also, the cotton of swamp. The propitious factor of bogging up, is the precise relief of the plateaus and nearness of underground waters to the surface. Except swamps, the wide sedge meadows are on the Ardahani plateau, at the heads of the Kura river. Quaternary superficial formations, which are formed here, are the polygenic and belong to the geological-genetical complexes of alluvial-lacustrine- swampy sediments.

429 CONCLUSIONS

The guarantor for effective development and optimal placing of economic and engineering objects in the pre-frontier territories of Turkey and Georgia is the estimation of stability of its geological environment. The basis for creating the geological environment of the territory, effectiveness of placing economic and engineering objects, providing stable economic development of the population and preventing the consequences of geological disaster is regional geological-engineering study and a geological map of 1:200 000 scale (Appendix,6). The engineering and geological map has been compiled on the basis of combination of homogeneity and changeability of the lithological composition, peculiarities and the state of rocks according to which 12 geological and engineering formations and 23 complexes have been established. Proceeding from the geomorphological peculiarities of the territories, each of the established complex is characterized by certain objective laws of development of dangerous geological processes and the spatial potential of slopes steadiness. On the basis of analyses of the executed works we have established the followings: Within the mountain systems of the East Pontides and Ajara-Trialeti smooth surfaces located in different hypsometric levels form vast areas necessary for vital functions of the population. But these surfaces are also favourable for the development of landslide processes which need to be prevented. The most dangerous geological processes in the region are the erosional-mudflow phenomena. According to the scale and the depth of occurrence, we distinguish tectonic seismogenic landslides (Meydancık, Murgul, Pınarlı, Posof, Süngülü, Danisparauli, Tsablana, Varjanuli, Gorjomi,Bertakana-Tmogvi, etc.) which need a special approach for their prevention which is expensive and sometimes ineffective. Usage of such areas for concrete solution of tasks needs a special approach and thorough studies. To preserve land, ensure protection of the population and steadiness of the slopes, of special importance become the consistential (climatogenic) landslides which are characterized by significant quantitative and areal extension (development) causing great damage to the economy of the both countries. It is worth noting that such landslides are relatively easy to be controlled. Within the mountain systems of the East Pontides and the Lesser Caucasus, the Quaternary glaciation and their deposits was much greater in scale and dropped to hypsometrically lower marks than it was supposed before. Besides there are irrefutable signs of the Wurm and the Riss Glaciations. To our mind, the principal problems of further studies are: 430 Comprehensive study of the genesis and the age of the surface removal, the border of extension and the cyclic recurrence of the Quaternary glaciation, modification of shore levels of the Black Sea and their deposits, plotting a scheme allowing for the analyses of the recent tectonics and the manifestations of young volcanism. Compilation of maps of engineering and geological conditions and the geodynamical potential of the territories of the Black Sea coast within the limits of Pontides in the scales 1:100 000 - 1: 200 000. To organize a lithomonitoring polygon for joint studies in the both countries, within a common geological system in the trans-frontier territory of the Chorokhi river basin. The problems of control of natural disasters, the criterion of physical load on the geological environment, the mechanism of regulation of the stable development of the population and urbanization balancing, motivation of the technical and economic projects of rational mastering and protecting natural environment and ecological safety will be worked out on this polygon. Further the polygon may become an international scientific center for methodical studies for lessening or liquidation of ecological disasters in the Black Sea countries.

431

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