Geological Society. 513 



crystalline or vitreous aspect, and contains crystals of hornblende 

 as well as much glassy felsimr. Within the range of Mr. Hamilton's 

 route it occurs about 2^ miles south of the village of Susuo-erli ; 

 also 9 miles south of SIniaul : and a little further the author ob- 

 tained the following descending section : 



1 . Hard volcanic tuff, slightly crystalline, but containing many 

 boulders and pebbles of trap, with numerous concretions of green 

 marl, 12 feet. 



2. Soft whitish volcanic earthy tuff, containing small frag- 

 ments of pumice, 10 feet. 



3. Hard crystalline but stratified rock. 



About the 11th and 12th miles from Simaul, peperite is overlaid 

 by a white limestone ; between the 15th and 16th it rests upon pro- 

 truded masses of decomposing trap or syenite ; and half a mile 

 further a mass of trachytic or trap conglomerate, forming the point 

 of separation of two valleys, has been raised up subsequent to its de- 

 position by a protrusion of trap, as the conglomerate, which is much 

 contorted, adheres to the side of the trap; and near the IGth mile, 

 it is underlaid by the micaceous sandstone. 



The beds are occasionally horizontal, but where the peperite has 

 been affected by the trachyte, they are variously incUned. 



7. Trachyte and Trachytic Co7iglomerate . — Several varieties of this 

 rock occur within Mr. Hamilton's district. The points more par- 

 ticularly mentioned are, one mile south of Kespit, where it forms a 

 ridge of hills ; the village of Kalburja, 7 miles S.W. of Kespit ; 

 also near the town of Bogaditza, whence a high trachytic range ex- 

 tends for a considerable distance east and west, succeeded by a less 

 elevated district of the same rock, which continues beyond Sin- 

 gerli to the foot of the DImirji mountains. In this district the tra- 

 cliyte varies greatly in colour, is generally soft, decomposes easily, 

 and the author was often unable to decide whether it was an aqueous 

 deposit of volcanic sand, or a subaqueous igneous rock. To tlie east 

 of Slngerli is a large mass of red porphyritic trachyte, considered by 

 Mr. Hamilton to be a coulee which has flowed from the high rugged 

 hills to the south-east. The trachytic rocks continue up the valley of 

 Macestus for several miles. It is also extensively developed south of 

 the Demirji chain between Simaul and Koola, particularly about the 

 13th or 14th mile from the former, and is overlaid by white lime- 

 stone. About the 1 9th mile, in some places, cliffs of trachytic conglo- 

 merate rest upon the peperite, and in others the trachytic conglo- 

 merate overlies horizontal beds of white marl belonging to tlie wliite 

 limestone, and interstratitied as before stated, with irregular beds of 

 quartz pebbles. 



8. Basalt is exposed south of the Demirji chain at several places, 

 but more j)articularly near and in the Katakekaumonc. 



A sj)ur of porphyritic traj) occurs al)out two miles soutli of Su- 

 sugerli. 



Hut Springs burst forth in great force about 7^ miles east of 

 Singerli. Their temperature is sujjjjosed by Mr. Hamilton to be 

 equal to that of boiling Vater. Extensive depositions. In one part 



Phil. Mag. S. 3. Vol. 14. No. 92. Suppl July, 1S39. 2 L 



