292 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Banna, from whence it may be traced in a continuous line, associated 

 with other igneous rocks and forming the lofty boundary-chain to 

 within a short distance of Bayazid at the foot of Mount Ararat. 



From their first appearance near Gulpaigan the granitic rocks 

 extend about 1 20 geographical miles in a single unbroken axis, 

 without offsets, to beyond Hamadan. 



This portion of the chain I have crossed at two points, — once 

 between Essadabad and Hamadan, — and again between the plains of 

 Japiilak and Biirujird. 



At Hamadan the granite of Kiih Elwend varies considerably in 

 character. 



Sometimes it is white and very coarsely grained, with a few 

 straggling laminae of mica, having a somewhat dendritic arrange- 

 ment. In another variety the crystals of quartz and felspar are 

 smaller (though still coarse), and the mica is more abundantly dif- 

 fused in grains. This passes into a fine-grained grey granite ; and 

 finally becomes a yellowish quartzose rock, enclosing large splashes 

 of hornblende, precious garnets, and a little mica. All these varieties 

 occur close to the Trilingual Tablets. Gold is occasionally found in 

 the courses of the streams flowing from Kiih Elwend. 



Throughout the whole line of its occurrence the granite of these 

 regions, owing to the abundance of felspar in its composition, is of a 

 very perishable nature, and therefore the ranges which it composes 

 have a rounded and undulating outline, not presenting any pic- 

 turesque or remarkable peaks. 



In ascending the Merwari Pass between Kermanshah and Senna we 

 have a coarse grey syenite, with large crystals of hornblende in a 

 base of white quartz and felspar, and containing magnetic oxide of 

 iron richly diffused through it. The same metal also occurs dis- 

 seminated through the dark-grey granite which constitutes the great 

 mass of the Pass. The summit is of red decomposed granite without 

 the metal. 



Between the plains of Japiilak and Biiriijird we have an interesting 

 section (fig. 13). The plain of Japiilak is a denuded valley of ele- 

 vation, in which the outcrop of blue clay-slates from beneath the 

 alluvial covering is frequently detected ; — the slates dipping from the 

 central axis, and traversed by veins of coloured quartz. 



On the low hills east of A'liabad village, at the northern end of 

 the plain, the quartz suddenly assumes a great development, and is 

 succeeded by a fine-grained and friable syenite, which is injected 

 through in low rounded bosses, elevating the slate-rocks into almost 

 a vertical position. On entering the Derbend, or Pass, the syenite 

 overlies a thick bed of white altered limestone, having been forced 

 through with such violence as to break up and carry with it large 

 masses and layers of the limestone, and also to spread itself over the 

 surface of the beds in situ, which are thrown down at an angle of 

 45° towards the East. Crushed and contorted, fissile blue clays 

 crop out conformably from below the white limestone. At the 

 entrance of the Japiilak stream through a gorge on the Western side 



