LOPTUS TURKO-PERSIAN FRONTIER. 323 



ornaments these tombs and the grave-yards of this locahty. The 

 fresh appearance of the designs is very remarkable. 



From Akhlat to Tadvan, the wide plain, rising towards Nimrdd 

 Dagh on the west, is wholly composed of friable grey tuff, which pro- 

 duces a very light, rich soil for grain. Pieces of pumice are abundantly 

 contained in it. When the Lake rose, the foundations of several 

 houses at the village of Yam fairly melted away and disappeared. 

 Near Zerakh the sand is thickly strewed with large lumps of pumice, 

 black scoriae, and obsidian, containing glassy felspar. The immense 

 quantity of volcanic products here observable is astonishing ; and I 

 was not long in discovering that other vents had been pouring forth 

 their contents in addition to Suphan Dagh. 



In the maps hitherto published, a curved bay is laid down on the 

 south shore of the Lake of Van, between Avatak and Narnigas. This 

 is in fact a very picturesque crater [see original Drawings Nos. IX. 

 and X.], much truncated, and having its wall towards the Lake broken 

 down so as to admit the water in a deep bay into the interior of the 

 crater. The ragged edge I estimated, at a distance, to be three or 

 four miles in circumference. The concentric layers, apparently of 

 sand, are distinctly seen in the basin, dipping outwards. It is not 

 remarkable that this crater has hitherto escaped observation, as it is 

 only visible to a person proceeding from Akhlat to Tadvan, — a road 

 seldom traversed. The highest point I judge to be about 600 or 800 

 feet above the Lake. 



I am also under the impression that Nimriid Dagh itself (which 

 is laid down as a range running N.E. and S.W.) is the base of an 

 enormous cone, rivalling Suphan Dagh ; with this difference, how- 

 ever, that, while the latter is of solid basaltic lava, the former is of 

 volcanic sand. The broken and precipitous edges of a cup-shaped 

 interior, having the layers dipping outwards, are seen in some posi- 

 tions. I was informed that, on clambering to the top, a person looks 

 down on the opposite side into a circular depression with a lake at 

 the bottom. If I should be correct in my supposition that Nimriid 

 Dagh is an extinct crater, there can be little difficulty in understand- 

 ing from whence the great quantity of sand at the western extremity 

 of the Lake of Van has been derived. 



Continuing west from Tadvan to the Bitlis Chai, the same friable, 

 light, volcanic, red sandstone appears at the surface as occurs at 

 Akhlat. 



The Kerkiir Dagh rises abruptly from the plain on the north of 

 the road ; its smooth sloping sides and remarkable crests for some 

 time arrest the attention before reaching it. Viewed, however, from 

 the S.S.E., it has the aspect of a volcanic cone less truncated than 

 that on the south side of the Lake [see original Drawing XI.]. It 

 is wholly composed of a white rock, which I take to be pumice and tuff. 



On advancing to the S.W., it is perceived that the westerly con- 

 tinuation of Kerkiir Dagh is a similar cone, joined on to the other, 

 but having its summit much more eroded and the crater filled up. 



On entering the narrow valley of the Bitlis Chai, the lofty moun- 

 tains on either side consist of grey quartzose rock, underlaid by soft 



z2 



