CAUCASUS, a mountain range, stretching north-west to south-east from the Strait of Kerch (between the Black sea and Sea of Azov) to the Caspian sea, over 9oom. long and varying from 3o to 14om. in width. In its general uniformity of direction, its comparatively narrow width, and its well-defined limits towards both south and north, it presents a closer analogy with the Pyre nees than with the Alps. The range, like the Pyrenees, maintains for considerable distances a high elevation, and is not cleft by natural passes, as in the Alps. In both ranges some of the highest summits stand on spurs of the main range, not on the main range itself, e.g., Mts. Elbruz and Kasbek, Dykh-tau, Koshtan-tau, Janga-tau and Shkara. For purposes of description it is convenient to consider the range in four sections, a western, a middle with two subsections and an eastern.
Western Caucasus.—This section, extending from the Strait of Kerch to Mt. Elbruz in 42° 4o' E., is over 42om. long, and runs parallel to the north-east coast of the Black sea and only a short distance from it. Between the main range and the sea there intervene at least two parallel ranges separated by deep glens, and behind it a third subsidiary par allel range, likewise separated by a deep valley, and known as the Bokovoi Khrebet.
All these ranges are crossed by numerous glens and gorges, and the rainfall being heavy and the exposure favourable, they are densely clothed with vegetation. Many of the spurs abut steeply upon the Black sea, so that this littoral region is very rugged and not readily accessible. The sea ward flanking ranges run up to 4,000ft.
and more, and in many places form cliffs which overhang the coast some 2,000 3,000f t., while the main range gradually ascends to I0,000–I2,000ft. as it advances east, the principal peaks being Fisht (8,040ft.), Oshten (9,2loft.), Shuguz (I o,64of t. ), and Psysh (12,4 2 5 f t.) . The main range is built up of hard crystalline rocks, and the subsidiary chains are composed of softer strata (Cretaceous and Tertiary) which are more easily disintegrated. The snowline is about 9,000f t. on the loftiest summits, and east of Oshten the crest of the main range is capped with perpetual snow and carries many hanging glaciers, while larger glaciers creep down the principal valleys. The few passes lie at relatively great altitudes, so that although the northern versants of the various ranges all have a gentle slope, communica tion between the Black sea and the valley of the Kuban, and the low steppe country beyond, is not easy. The more important passes, proceeding from west to east. are Pshekh (5 ,43 5 f t.) , and Shetlib (6,o6oft.), Pseashka (6,88oft.), Sanchar (7,99oft.) ; be tween the last-named and Elbruz are the passes of Marukh (II,5ooft.), Klukhor (9,450ft.) and Nakhar (9,615ft.).
Owing to topographical and climatic conditions the southern exposure fosters a luxuriant and abundant vegetation. The most distinguishing feature of the flora is the predominance of arbores cent growths; forests cover 56% of the area and are not only dense but laced together with climbing and twining plants. The commonest species of trees are such as grow in central Europe, viz., ash, fir, pine, beech, acacia, maple, birch, box, chestnut, laurel, holm-oak, poplar, elm, lime, yew, elder, willow, oak. The common box is especially prevalent, but the preponderating species are Coni f erne, including the Caucasian species Pinus halepensis and P. insignis. The commonest firs are Abies nordmannia and A. ori entalis. There are two native oaks, Quercus ponticus and Q. ses siliflora. A great variety of shrubs grow on these slopes of the western Caucasus, chiefly the following species, several of which are indigenous—Rhododendron ponticum, Azalea pontica, Aris totelia inaqui, Agave americana, Cephalaria tatarica, Cotoneaster pyracantha, Citrus aurantium, Diospyros ebenum, Ficus carica, Illicium anisatum, Ligustrum caucasicum, Punica granatum, Phila delphus coronarius, Pyrus salicifolia, Rhus cotinus and six species of Viburnum. A great variety of aquatic plants thrive excellently. The following purely Caucasian species also grow on the coast— five species of spearwort, three of saxifrage, Aster caucasica, Dios corea caucasica, Echinops raddeanus, Hedera colchica, Helleborus caucasica and Peucedanum caucasicum. Here too are found mag nolia, azalea, camellia, begonia and paulownia. Among the culti vated trees and shrubs the most valuable are the vine, peach, pomegranate, fig, olive (up to 1,5ooft. above sea-level), chestnut, apricot, apple, pear, plum, cherry, melon, tea (on the coast between Sukhum-Kaleh and Batum), maize (yielding the staple food of the inhabitants), wheat (up to 6,000ft.), potatoes, peas, currants, cotton, rice, colza and tobacco. After the Russian con quest half a million of the inhabitants of this region being Moham medans, and refusing to submit to the yoke of Christian Russia, emigrated into Turkish territory, and the country where they had lived remained for the most part unoccupied until after the begin ning of the loth century. The coast-line is remarkably regular, there being no deep bays and few seaports. The best accommoda tion that these latter afford consists of more or less open road steads, e.g., Novorossiisk, Gelenjik, Anapa, Sukhum-Kaleh, Poti and Batum. Along the coast are summer bathing resorts similar to those of the south-east coast of the Crimea. The largest are Anapa, Gelenjik and Gagry.
Middle Caucasus: (a) Western Half.—This sub-section, hav ing a length of 200m., reaches from Mt. Elbruz to Kasbek and the Pass of Darial. It contains the loftiest peaks of the whole range, of which those above 15,000ft. are:—Elbruz (west peak) 18,465ft. and (east peak) 18,345f t., Jaikyl 17, 7 8of t., Dykh-tau 17,o5oft., Shkara 17,o4oft., Koshtan-tau 16,875ft., Janga-tau 16,66oft. (west peak) and 16,525ft. (east peak), Kasbek 16,545ft., Mishirghi-tau 16,41 oft. (west peak) and 16,3 5of t. (east peak), Adish or Katuyn tau 16, 295f t., Gestola 15 ,94of t., Tetnuld 15,9 2of t., Gimarai-Khokh 15,67oft., Ushba 15,41oft. (south-west peak) and 15,400ft. (north east peak), Ullu-auz 15,35oft., Adai-Khokh 15,275ft., Tikhtengen 15,13 5 f t., Tiutiun-tau 15,115 ft.
t.
The crest of the main range runs at an altitude exceeding io,000ft., but is surpassed in elevation by the secondary range to the north, the Bokovoi Khrebet. These ranges are connected by more than half a dozen short transverse spurs enclosing as many cirques. Besides the Bokovoi Khrebet several other short subsi diary ranges branch off from the main range at acute angles, with high glens between them. Down all these glens glacier streams descend, until they find an opportunity to pierce through the flank ing ranges, which they do in deep gorges, and then race down the northern slopes of the mountains to enter the Terek or the Kuban, or down the southern versant to join the Rion or the Kura. Amongst all these high glens there is a remarkable absence of lakes and waterfalls; nor are there down in the lower valleys, as one would expect in a region so extensively glaciated, any sheets of water corresponding to the Swiss lakes. In this section of the Caucasus the loftiest peaks do not as a rule rise on the main range, but in many cases on the short spurs that link it with the Bokovoi Khrebet and other subsidiary ranges.
Glaciers.—The snow-line runs at 9,500 to •I o,000f t. on the northern face and i,000ft. higher on the southern face. There are over 90o glaciers in this section, and although they often rival those of the Alps in size, they do not descend generally to such low altitudes. The best known are the Bezingi or Ullu, between Dykh-tau and Janga-tau, 102m. long, and descending to 6,535ft. above sea-level ; Leksyr, situated south of Adyr-su-bashi, 72m. long, and its end at 5,69oft., the lowest point to which any glacier descends on the south side of the range; Tseya or Zea, descending 6m. from the Adai-khokh to 6, 73 of t. ; Karagom, from the same mountain, 92m. long, and reaching down to 5,79oft., the lowest on the northern side; Dyevdorak or Devdorak, from Kasbek, 22m. long, its end at 7, 53of t. ; Khaldeh or Geresho 4-1m. long, from Shkara and Janga-tau ; Tuyber from Tetnuld, 62m. long, and reaching down to 6,565ft.; Tsanner or Zanner, the same length, but stopping short 24oft. higher, likewise given off by Tetnuld; while between that peak, Adish and Gestola originates the Adish or Lardkhat glacier, 5m. long and terminating at 7,45oft. The total area covered by glaciers in the central Caucasus is estimated at 625 to 65osq.m., the longest being the Maliev on Kasbek, 36m. long; but according to M. Rossikov several of the largest glaciers are retreating, the Tseya at the rate of something like 40-45ft. per annum.
Flora.—In this section of the range again the southern slopes are clothed with vegetation of remarkable luxuriance and richness, more especially in the region of Svanetia E.) . Here again the plants are bigger and the blossoms more abundant than in the Alps, forests of Coni f erae predominate, and gigantic male ferns (Aspidium filix-mas), Paris incomplete (a member of the Trilliaceae), Usnea or tree-moss, box, holly (Ilex aquifolium), Lilium monadelphum and many of the herbaceous plants which flower in English gardens, grow here to an extraordinary size— monkshoods, Cephalaria, Mulgedia and groundsels. Other species are Campanula, Pyrethrum, aconite, Cephaelis, speedwell, Alche milla sericea, Centaurea macrocephala, Primula grandis and a species of primrose. Flowers of great beauty and abundance blos som up to 13,000f t. on the northern slope and on the southern slope ascend 2,000ft. higher. Walnuts grow up to an altitude of 5.40oft., the vine and mulberry to 3,25oft., the lime and ash to 4,000f t. The forests extend to the upper end of the limestone gorges. Above that the crystalline schists are bare of tree vegeta tion. The upper limit of arborescent vegetation is 7,00o-7,500ft., of shrubs, e.g., rhododendrons, 8,5ooft., and of pasture-lands up to 9,000f t. The principal cultivated varieties of plants in this section are wheat, rye, oats, barley, beans, millet and tobacco.
The most noteworthy feature of this section is the broad high land region o f Daghestan, which flanks the main range on the north and sinks down to the Caspian sea (east), and to the valley of the Terek (north). On the north-west this rugged highland region is well defined by the transverse ridge of Andi, which to the east of Kasbek strikes off from the Caucasus range almost at right angles. The rest of the Daghestan region consists of a series of roughly parallel folds, of Jurassic age, ranging in altitudes from 7,50o up to 12,500f t., separated by deep river glens which cut it up into a number of arid, treeless plateaus. The most prominent of these tablelands is Bash-lam, which stretches east and west between the Chanti Argun and the Andian Koisu. Upon it rise the conspicuous peaks of Tebulos-mta (14,775f t. ), Tugo-mta (13,795f t. ), Komito tavi or Kachu (14,oloft.), Donos-mta (13,56oft.), Diklos-mta , t.) , Kvavlos-mta or Kolos-mta (13,o8of t.) , Motshekh tsferi (13,I 4of t.) and Galavanas-tsferi (13, 2 6of t.) . Farther east is the Bogos tableland, stretching from south-south-west to east north-east between the Andian Koisu and the Avarian Koisu and rising to over 13,400ft. in several peaks, e.g., Antshovala (13, t. ), Botshokh-meer (13,5I 5f t. ), Kosara-ku (13,420f t.) and Addala-shuogchol-meer (13,58oft.); and the Dyulty tableland reaching 12,400f t. between the Kara Koisu and the Kazikumukh Koisu. Neve and glaciers occur on some of these peaks, particu larly on the slopes of Diklos-mta, where the glaciers descend to 7, 700f t. (north) and to 8,3 5of t. (south) . Here the passes are lower than those between Elbruz and Kasbek, though at appre ciable heights, fully equal to those that lead up from the Black sea to the valley of the Kuban in the western section of the range. The best known are the Krestovaya Gora (7,8o5f t.) on the Geor gian military road south of Darial; Kodor (9,3ooft.) and Sats kheni, and Gudur (I o, I 2of t.) and Salavat (9, 28of t.) , carrying the Akhty military road.
The flora of this section bears a general resemblance to that farther west. Ample details will be found in Dr. G. Radde's (1831-1903) monographs on Daghestan.
Between the northern and the southern sides of the range there is a great difference in climate, productions and scenery. In the south-western slopes and valleys where a heavy rainfall is com bined with a warm temperature, magnificent forests clothe the mountain-sides and reach the waters of the Black sea. There the littoral from, say, Sukhum-kaleh to Batum, and the inland parts of the basin of the Rion, will bear comparison with any of the prov inces of Italy in richness and variety of products. But farther inland, east of Tiflis, a great change becomes noticeable on the other side of the transverse ridge of the Suram or Meskes moun tains. Arid upland plains and parched hillsides take the place of the rich verdure and luxuriant arborescent growth of Imeretia, Svanetia and Mingrelia, the districts which occupy the valleys of the Ingur and Rion and the tributaries of the latter. A very simi lar change likewise becomes noticeable in the higher regions of the Caucasus mountains north of the pass of Mamison. The val leys of the Rion and Ardon and of others that flow in the same direction, are almost wholly destitute of trees, but where the bare rock does not prevail, the mountain slopes are carpeted with grass. "Treeless valleys, bold rocks, slopes of forbidding steepness (even to eyes accustomed to those of the Alps), and stone-built villages, scarcely distinguishable from the neighbouring crags" (Freshfield). Austere and unattractive though those valleys are, the same epi thets cannot be applied to the deep gorges by which in most cases the streams make their escape through the northern subsidiary range. These defiles are declared to be superior in grandeur to anything of the kind in the Alps. That of Darial (the Terek) is fairly well known, but those of the Cherek and the Urukh, farther west, are stated to be still more magnificent. Not only do the snow-clad ranges and the ice-panoplied peaks surpass the loftiest summits of the Alps in altitude ; they also in many cases excel them in boldness and picturesqueness of outline, and equal the most difficult of them in steepness and relative inaccessibility.
The geological sequence begins with the granite and schists of the central zone, which extend from Fisht (west) to some distance beyond Kasbek (east). Then follow the Palaeozoic schists and slates. Fossils are extremely rare in these beds; Buthotrephis has long been known, and traces of Calamites and ferns, and in the west fossils which appear to indicate a Devonian age. Upon the Palaeozoic rest Mesozoic deposits (Lias to Upper Cretaceous). Different views exist as to the position of unconformities, but important ones occur at the base of the Tithonian (Upper Juras sic) and at the base of the Trias. In general the Upper Jurassic beds are much more calcareous on the north than they are on the south. The Mesozoic are followed by Tertiary deposits, which on the north are nearly horizontal but on the south are in part included in the folds—the Eocene and Miocene being folded, while later beds, though sometimes elevated, may not be affected by the folding. The final folding of the chain, proceeding from north-east, undoubtedly occurred at the end of the Miocene period. Folding also occurred probably during the Permian and again dur ing the Upper Jurassic (direction south-west). Also the difference in character of the Jurassic beds on the two sides of the chain appears to indicate that a ridge existed in that period. The last phase in the history of the Caucasus was the growth of the great volcanoes of Elbruz and Kasbek, which stand upon the old rocks of the central zone, and by the outflow of sheets of lava upon the sides of the chain. The cones are composed largely of acid ande sites, but many of the lavas are augite andesitex and basalts. There seem to have been two periods of eruption, and as some of the lavas have flowed over Quaternary gravels, the latest out bursts must have been of very recent date.
Near the northern foot of the Caucasus, especially near the hot mineral springs of Pyatigorsk, a group of igneous rocks rises above the plain. They are laccolites of trachytic rock, and raised the Tertiary beds above them in the form of blisters. Subsequent denudation has removed the sedimentary covering and exposed the igneous core. Petroleum occurs in the Tertiary beds at both ends of the chain.
But, apart from Georgia, historical interest in Caucasia centres in the long and persistent attempts which the Russians made to conquer it, and the heroic, though unavailing, resistance offered by the mountain races, more especially the Circassian and Lesghian tribes. Russian aggression began early in the 18th cen tury, when Peter the Great, establishing his base at Astrakhan on the Volga, and using the Caspian for bringing up supplies and munitions of war, captured Derbent from the Persians in 1722, and Baku in 1723. But these conquests, with others made at the expense of Persia, were restored to the latter power after Peter's death, a dozen years later. At that period the Georgians were divided into various petty principalities, the chief of which were Imeretia and Georgia (Kharthlia), owing at times a more or less shadowy allegiance to the Ottoman sultan. In 177o, when at war with Turkey, the Russians crossed over the Caucasus and assisted the Imeretians to resist the Turks, and from the time of the ensuing peace of Kuchuk-kainarji the Georgian principalities looked to Russia as their protector against the Turks. In 1783 George XIII., prince of Georgia and Mingrelia, formally put himself under the suzerainty of Russia, and after his death Georgia was converted (18o1) into a Russian province. The same fate overtook Imeretia nine years later. Meanwhile the Russians had also subdued the Ossetes (1802) and the Lesghian tribes (1803) of the middle Caucasus. By the peace of Gulistan in 1813 Persia ceded to Russia several districts in Eastern Caucasia, from Len koran northwards to Derbent. Nevertheless the mountain tribes were still independent, and their subjugation cost Russia a sus tained effort of thirty years. At first the Russians were able to continue their policy of conquest and annexation without serious check. Af ter acquiring the northern edge of the Armenian plateau, partly from Persia in 1828 and partly from Turkey in 1829, Russia in 1832 crushed a rising in Daghestan. The next seven years were occupied with the subjugation of the Abkhasians along the Black sea coast, and of other Circassian tribes in the west. Meanwhile Shamyl, a chief and religious leader of the Lesghians, had roused the Lesghian tribes farther east. His resistance was finally broken after 20 years of warfare by Prince Baryatinsky, who succeeded in capturing Shamyl's stronghold of Weden, and then in surrounding and capturing (1859) that chieftain himself on the inaccessible rocky platform of Gunib in the heart of Daghestan. But it was not until 1864 that the Russians finally stifled all opposition. Then .followed a wholesale emigration of the Circassians, who sought an asylum in Turkish territory, leaving their native region almost uninhabited and desolate. During the Russo-Turkish War of 1877-78 the self-exiled Circassians and other Caucasian mountaineers, supported by a force of 14,00o Turks, made a determined attempt to wrest their native glens from the power of Russia ; but, after suffering a severe defeat at the hands of General Alkhazov, the Turks withdrew, and were accompanied by some 30,00o Abkhasians, who settled in Asia Minor. A few months later the Lesghians in Daghestan, who had risen in revolt, were defeated and their country once more re duced to obedience. By the peace of Adrianople, Russia still further enlarged her Transcaucasian territories by the acquisition of the districts of Kars, Batum and Ardahan. Af ter a peaceful period of a quarter of a century the Armenian subjects of Russia in Transcaucasia were filled with bitterness and discontent by the confiscation of the properties of their national (Gregorian) Church by the Russian treasury. Nor were their feelings more than half allayed by the arrangement which made their ecclesias tics salaried officers of the Russian state. This ferment of unrest, which was provoked in the years 1903-04, was exacerbated by the renewed outbreak of the century-long racial feud between the Tatars and the Armenians, at Baku and other places. Nearly the whole of the region between the Caucasus and the Perso Turkish frontier on the south, from the Caspian sea on the one side to the Black sea on the other, was embroiled in a civil war of the most sanguinary and ruthless character, the inveterate racial animosities of the combatants being in both cases inflamed by religious fanaticism. An end was put to these disorders only by the mutual agreement of the two contestants in Sept. 1905.
The Revolution of 1905 in Russia aroused the desire for self government that has never long been dormant in the Caucasus. The agrarian policy of the Tsarist Government added fuel to the fire of discontent, and the refusal to recognize their individual national languages was a further source of grievance to Armenians, Tatars and Georgians alike. Nevertheless the Russian Govern ment ruthlessly pursued its repressive policy. On the outbreak of the World War in 1914, when they had learnt that Russia was the ally of France and Great Britain, the Caucasian nationalities eagerly responded to the call to arms. But even this action had no effect upon the Russian Government, and the governship of General Yudenitch was specially noteworthy for its severity. Hence the February Revolution of 1917 was hailed with joy throughout the Caucasus when the individual nationalities at tempted to establish a Federal republic that should be governed by a Transcaucasian diet. But the failure of Kerensky's ad ministration and the triumph of Bolshevism spelt failure for the Caucasian Republic also. The component states made a brief attempt to preserve their independence of Moscow under mildly socialistic forms of government, but the military strength of the Soviet soon overcame their resistance. First one and then another was overrun and conquered, and Soviet republics set up under the guidance of Moscow. Despite the maintenance by the Moscow Government of these republics in the Caucasus, the desire amongst some of the population for complete independence of the U.S.S.R. has not been extinguished.