Hitherto our study of the orography of this Tauric Armenia has been mainly occupied—it is interesting to recall the fact—with lines of folding of the earth’s crust. Indeed the country as a whole has not been subjected to recent volcanic action in the same degree as the plateau regions lying to the north of the spinal mountains—the territories of Akhaltsykh, Ardahan, Akhalkalaki, Alexandropol and Kars. At the same time it has not escaped the operation of these agencies; nor have they worked upon a less impressive scale. Be it lavas flooding over the sedimentary deposits and levelling the inequalities of the ground—what more startling manifestation could be offered of the process than the Bingöl plateau with its piled-up layers of lava and tuff? Or if volcanoes in the strict sense be matched against volcanoes, there are Nimrud and Sipan to enter the lists with Alagöz and Ararat. Several mountains which are due to eruptive action have been added to the map in the course of my own journeys. Such are Bilejan and Kartevin. The roll will be increased as our knowledge is carried further of the districts on the west of Bingöl and Palandöken.
A striking analogy in some respects to the Russian territories which I have just specified is provided by the surface features of the Bingöl plateau, with its continuation northwards in the shape of a deeply eroded block of land to the confines of the plains of Erzerum and Pasin. This extensive region lies about south-west of the corresponding area of rectangular shape within the Russian frontier. It performs the same function of a roof to the adjacent countries; and just as the one stage gives birth to the Kur and the Arpa Chai, so the other feeds with countless channels the earliest course of the Araxes and contributes the largest proportion of the waters of the Murad. The streams which decline from its north-westerly extremities swell the volume of the Western Euphrates. Built up on the south with lavas and tuffs to the extent of thousands of feet, it has throughout been flooded with volcanic matter. Taken in relation with the general structure of Tauric or Turkish Armenia, we may apply to this elevated stage of the plateau country the designation of the Central Tableland.
My reader is already familiar with the characteristics of the region—the basin-like appearance, the long parapets on the northern and southern edges, in the one case culminating in the volcanic peaks of Palandöken (10,694 feet) and Eyerli, in the other distinguished by the eminences of Bingöl (nearly 10,800 feet). The limits of the Bingöl plateau are clearly defined on three sides, and may readily be recognised on our map. On the north it merges insensibly into the Shushar and Tekman districts, though at some points, as, for example, the cliffs just south of Kherbesor, lines of demarcation may be laid down. How the waters of this plateau converge together in the shape of two fans, as they are precipitated from the highest levels towards the north and towards the east, burying themselves ever deeper into the volcanic soil! The one group is collected in the plain of Khinis, and the other by the course of the Araxes between the plain of Altun and the narrows on the north of Kulli. There in the hollow of the basin the levels are still lofty—the Altun plain with about 7000 feet and Kulli with about 6000. Ascend to the table surface from the beds of the rivers, and you register heights which range between 7000 and at least 9000 feet above the sea. A country with down-like outlines, composed of limestones with intrusive serpentines and Pliocene lake deposits capped by sheets of the ubiquitous lava—an expanse sterile and vast at all seasons, and in winter covered with snow—a softly billowing surface dappled by the shadows of cumulus clouds and shot with colour from a network of blue streams—such, I think, are the most permanent impressions of our journeys across the Central Tableland.
Volcanic action is largely responsible for the configuration of this tract of country, filling up hollows, preserving the sedimentary deposits with overlying sheets of lava. The extent of the operation may best be gauged on the south-western extremities of the Bingöl plateau. There the ridges in the west are seen stepping up, one after another, almost to the margin of the elevated platform where your tents are spread. The setting sun invests them with an added glamour of gold and purple; yet how futile this fretful array against the solid land about you, dimly spread in horizontal spaces beyond sight! The yellow mullein which scents the air springs from the ruin of all those ridges, growing upon the tomb of their deeply-buried remains. But further north, where the sway of the lavas has already become feeble, the same phenomenon, a little modified, may be observed. Survey the scene as it is unfolded northwards from the western summit of Bingöl or from the hill of Gugoghlan (Ch. XXII. p. 373, Figs. 194 and 195). What a contrast between the landscape of the west and that of the east! All those ridges in the west are dying by themselves into the down-like spaces of the Central Tableland. Here the lavas have been a contributing but not the principal cause.
The truth is that we should here be standing quite near the point of greatest constriction between the inner and outer arcs. In other words, it is just west of this region that the greatest compression of the Armenian highlands by earth movements may be supposed to have taken place. A natural consequence of the process would be the ridging up within a narrow space of the normal surface elevations. East of an imaginary line between Bingöl and Palandöken the area becomes enlarged. Room is given for the ridges to spread; they flatten out and almost disappear. At the same time the change from the Tauric into the Iranian direction soon commences to make itself felt. Mountain and gentle hill, the rocks on the heights and those in the hollows are all imprinted with the stamp of a new-born force. In the most central districts we recorded this change in what geologists call the strike between the villages of Kanjean and Alkhes in the region called Elmali Dere or Vale of Apples. There the stratified rocks have been flooded with sheets of lava, which have presumably welled up from fissures. A glance at the map will show that all the outlines are bending over, those on the north-east and those to the south-west of this point. And a little looking brings home the fact that most of the great Armenian volcanoes are situated at or near the bend.
The tendency to a strong-pronounced plateau country is in Armenia, and especially in the south-western territories, independent of volcanic action. Hermann Abich aptly describes the effect of this tendency upon the mountain masses when he speaks of their constant, nearly horizontal summit line.[14] Yet the heights which elicited this appreciation belong to the system west of Bingöl, and are mainly composed of stratified rocks. Horizontality is the prevailing characteristic of the outlines on the north of the series of plains from Pasin in the east to Erzinjan in the west. Those outlines belong to a block of elevated land from over 9000 to about 8000 feet above the sea. Lavas have accentuated the feature in the case of the border heights of Pasin (Ch. VIII. p. 193, [Fig. 163]); but when, further west, the barrier consists of limestones and old igneous rocks, the same appearance of a flat-topped mass, representing a higher stage of the plateau region, is only varied by some beautiful shapes emerging upon the sky-line, such as the Cretaceous peaks of Akhbaba and Jejen. If you draw a section between the western extremity of the plain of Mush against Taurus and the maze of valleys which feed the Chorokh on the north of Erzerum, the true character of the land will be exhibited in a striking manner. You will commence with a level plain of immense extent from west to east and with an average elevation of 4200 feet. Proceeding northwards, you scale a wall of 8000 feet, only to find yourself upon a platform almost as flat as a billiard-table, over which the track leads without much change in level for a distance of many miles. This stage breaks off upon the north to a little plain even as water, lying in the lap of an extensive depression of not more than 5000 feet. You cross the depression with a parapet of 8400 to over 9000 feet closing the landscape with gigantic cliffs before your eyes. It is the edge of the Central Tableland. The journey is long from this, its southern margin, to the corresponding rim upon the north—water-worn downs with an average altitude of over 7000 feet. After registering heights, always on the level, of about 9000 feet, a descent is made to the vast expanse of the Erzerum plain (5700 feet). The mass which rises on the north of that plain contains the sources of the Western Euphrates and leads over to the deep valleys which sustain the Chorokh. It is flat-topped, and attains a level of about 9000 feet.
The most fertile and agricultural districts lie to the east of this section; they are generally separated one from another by mountains of recent volcanic origin, upon which, however, with the possible exception of the Tendurek Dagh, a wreath of smoke is never seen. The plain of Khinis (5500 feet) is screened by Khamur from the plains of Bulanik and Melazkert (5000 feet), where some of the finest grain in the world is grown. Bulanik is divided into a western and an eastern territory by the radial volcanic mass of Bilejan. The line of heights which are interposed between Western Bulanik and Mush plain are probably partly due to lavas which have welled up from fissures, and are easily crossed almost at any point. The plain of Mush (4200 feet) and the level country of almost endless extent between Sipan and the Murad are shut off from the cornfields and orchards of the basin of Lake Van (5637 feet) by the immense circumference of the Nimrud crater and by the block of limestones and lake deposits upon which Sipan is built up. The region between Lake Van and the hills of the Persian border is parcelled out into a number of districts by such volcanic eminences as Varag Dagh, Pir Reshid Dagh,[15] and Tendurek Dagh, which last-named mountain has sent its lavas a great distance south into the Abagha Plain.[16] All the way from Tendurek to the plain of Khinis eruptive agencies have fastened upon the land on a considerable scale. A large area is occupied by the radial volcanic system known as the Ala Dagh, but very scantily explored. It is succeeded further west by the Kartevin Dagh. The extensive territories between Kartevin on the south, the plain of Khinis on the west, and the Sharian-Mergemir Dagh barrier on the north, are for the most part covered with sheets of lava. But the plains of Alashkert (5500 feet) and Pasin (over 5000 feet) are worthy to rank with the most favoured regions; and this sequence is continued westwards by the plains of the Western Euphrates, commencing with that of Erzerum (from 5750 to about 3800 feet). North again of this series one may specially instance the plain of Baiburt (5000 feet), which is a typical Armenian plain.
As you travel from plain to plain, from one basin to another, the horizon is most often filled by some shapely volcanic outline, slowly rising from the floor of the expanse. Yet the stratified rocks are seldom absent, emerging from the volcanic layers or only capped by a thin sheet of lava. Dominant among them are the limestones of various geological periods, from the Cretaceous and probably earlier, to the Pliocene deposits, when the greater part of the country must have been covered by a lake of fresh or brackish water. Intrusive in the earlier limestones are found a variety of old igneous rocks, such as diabase, gabbro and serpentine. The serpentines combine with the limestones to form rounded hills or downs with soft outlines. Sometimes a cap of lava has preserved a particular piece of limestone, and the result has been a summit with a point like that of a needle overtopping adjacent and undulating forms. Where the old igneous rock occurs in a zone, a sombre landscape is forthcoming, as for instance above the northern shore of Lake Van between Akhlat and Adeljivas. Or when the highly marmorised older limestones have the upper hand, there ensue sterility and glaring light. These latter rocks have a fairly wide extension and compose prominent lines of mountain. For example, they have bestowed upon the plain of Khinis its northern boundary; and nowhere are they seen to greater advantage than in that shining and richly modelled barrier appropriately named the Akh Dagh or White Mountain. During the journey from Gopal to Tutakh on the Upper Murad they were constantly emerging from the sheets of lava; and in the south we found them in the vicinity of the southern peripheral mountains. They alternate with mica-schist in the Elmali Dere and Güzel Dere, districts at the south-western extremity of Lake Van. And they stretch across the water to form the promontory of Tadvan.
A rather later series of limestones would appear to be represented by the slopes over which we climbed to the Vavuk Pass between Gümüshkhaneh and Baiburt. There they are placed on the very threshold of the Armenian tableland; and they are distributed in a wide zone over the northern districts of Armenia, extending all the way from the Merjan-Muzur Dagh in the west to be represented by many a summit of the deeply eroded Chorokh region. The block of heights on the north of the Western Euphrates is composed to a great extent of such limestones; and both in the neighbourhood of the Kop Pass, and during the descent northwards from the pass of Khoshab Punar, we have been able to identify them by the evidence of fossils as belonging to the Cretaceous period. The several startling eminences from the surface of this elevated stage—a surface which is characterised by prevailing flatness and horizontality of the summit-line—are mostly due to upstanding masses of limestone, such as Akhbaba and Jejen. In the south we recognised the fossils of this same series of rocks upon the line of hills which border upon the north the great depression of the plain of Mush, where these give passage to the Murad.
Later still in date, and of almost constant prominence in the landscapes both of the plateau region and of the peripheral mountains, are the limestones of Eocene age. They are, perhaps, more usually associated with softer features, especially when they are interbedded with shales. Writing from memory, one may best recall the incidence of their impressive features at such widely distant points as the Palandöken line of heights, on the south of Erzerum and Pasin, and where they whiten the waters of Lake Van in the neighbourhood of Adeljivas. This pretty town with sweet-sounding name lies at the foot of a lofty cliff composed exclusively of white chalk. As you lunch in one of the caves along the road from Akhlat, numerous corals are observed imbedded in the rock. Even where volcanic action has fastened upon such heights with greatest persistency, the white face of this rock or of the softer Pliocene deposit is seldom absent from the scene. Eocene limestones and Pliocene deposits are prominent over the area of the Central Tableland; and the limestone emerges on the further side of the plain of Khinis to compose the Zirnek Dagh, continuing the outline of Khamur. The almost limitless expanse through which the Murad winds between Tutakh and Melazkert reveals most clearly its essential character as a country of rolling chalk downs beneath the covering of a cloak of lava. The southern limit of that expanse would seem to the eye to be volcanic, misled by the precedent of the immense extension of the train of Ararat. But when the barrier is at length reached it is found to consist of Eocene and Pliocene limestones, forming a pedestal for the fabric of Sipan.