But neither Oswald nor myself regretted our wanderings. By adhering to the higher levels we obtained a picture of structural features, which not only confirmed the studies we had pursued together, but also contributed several interesting facts. It is in this region that the great lines of elevation and mountain-making describe that beautiful curve which attains its greatest orographical significance in the mountains which border the highlands of Armenia and Persia on the north and on the south. In the south it is the line of the Armenian Taurus arching over into that of the Zagros chain; while in the north the wider span of the alps of Pontus and the Chorokh region is deflected into the border range of Russian Armenia and into the mountains of Khorasan. [225] Within the area of the Armenian tableland this curve may be clearly traced; for instance, it is conspicuous in the trend of the mountains from Palandöken to Kilich Gedik, and in that of the Aghri Dagh further north. Even in the country over which we were travelling, some distance south of the former of these barriers, and of comparatively even nature, the strike of the stratified rocks displayed the change in direction; while the sheets of lava, which overlay them, were evidently due to zones of weakness, where the stress of bending over had been attended with fracture, and the apex of the arc had given way. Speaking generally, the rocks consisted of older limestone, hardened into marble, and varied by igneous material, crystalline in character and of intrusive origin. Upon this foundation rested layers of later limestone; while over all were outspread the lavas, sometimes covering the entire series, at others swathing the base of marble eminences. These lavas had welled up from fissures, for the most part on the north of our track; they had flowed towards the south, in the direction of the still distant Murad, often following the trough of the river valleys, and sometimes altering the course of the drainage. The change of strike in the stratified rocks was observed in the neighbourhood of the village of Alkhes. There the axis of the limestone folds was almost latitudinal; and, as we neared Tutakh, it assumed a direction of east-south-east. This was also the direction of the several valleys between Alkhes and the Murad.