Geology of part of Asia Minor. 595 



south sides, perfectly free, from a vast level plain. On the west, indeed, the 

 plain is narrow,as the mountain is separated from the hills of Injesu only by a 

 flat valley one or two miles wide, down which a small stream flows in the winter, 

 into the lake in the plain of Caesarea. As I did not proceed up this valley, I 

 cannot affirm that it is continuous the whole way to the plain of Kara-hissar, 

 which is to the south of Mount Argaius ; but I believe it to be so. 



A short way from the first ridge of hills, which stretches down from Mount 

 ArgaBUS, the plain is covered with a thin saline efflorescence, apparently mu- 

 riate of soda. This ridge, which is narrow and rugged, consists of compact 

 black basalt, evidently one of the most recent coulees which have burst forth 

 from the sides of the mountain. Between the ridge and the next mass of rock, 

 a porphyritic and feldspathic trachyte, numerous springs of water rise and 

 flow north into the plain. They are derived from the partial melting of the 

 perpetual snows and glaciers on the summit of the mountain, the water having 

 percolated through the porous rock. 



The remaining formations, which the section crosses as far as Caesarea, are 

 trachytic, more or less compact, and more or less conchoidal in fracture. They 

 vary in colour from dark gray to brown and dark red, and contain numerous 

 imbedded masses of carbonate of lime. Near the summit of Yelanli Dagh, a 

 little off" the hne of section, is a very deep and rocky crater, near the summit 

 of a ridge, in many parts almost perpendicular. Towards the north-east, the 

 sides of the crater have been broken away ; but no trace of a lava stream can 

 be seen extending from them. 



Caesarea is situated in the plain, at the foot of the lower hills, which slope 

 down to the North from Mount Argaeus. The diluvial soil near the town is 

 much impregnated with nitre, which is worked and sent to Constantinople for 

 the manufacture of gunpowder. 



The plain extends from E.N.E. to W.S.W., and the hifls which form the 

 southern boundary consist for eight or ten miles N.E. from Caesarea, entirely 

 of hard, tufaceous rock. 



Section 6 represents the hills at a spot nine or ten miles W.N.W. from 

 Caesarea, where the Karasu or Melas flows out of the plain of Ctesarea to the 

 N.W., through a narrow gorge, into the Kizil Irmak or Halys. This section 

 bears a great resemblance to the formations to the south, through which the 

 general section passes, and consists of beds of white and yellow tuff or pepe- 

 rite, filling hollows and valleys in the pre-existing trachyte, some of the tuff* 

 being also capped witti basalt. Lower down and near the river are a few 

 horizontal beds of white limestone, which are probably of a much more recent 

 origin, as they appear to rest against and overlie the tuff", although conform- 



VOL. V. SECOND SERIES. 4 H 



