158 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



west of the Hot Bath Valley, on the summit of which stand two 

 remarkable peaks, known by the name of the Two Brothers. 

 These peaks, although separated only by a few hundred yards, 

 consist of detached masses of a grey semi-crystalline limestone, of 

 about 300 feet in thickness. A chain of calcareous matter, of 

 variable thickness, may be traced through the whole mountain to 

 the south-west, following the line of stratification ; and being more 

 durable than the associated shales, the harder rocks stand up in 

 isolated points above the wasted strata in which they are embedded, 

 and with which the stratification of the limestone is always con- 

 formable. 



They are, however, split and shattered by numerous transverse 

 fissures, which at a short distance appear like lines of stratification. 

 In the shales which underlie these rocks occur calcareous lamina? 

 as well as calcareous nodules, varying in size from that of a nut 

 to that of an orange. The shales are here very friable, and of a 

 pale chocolate or cream colour, like those at the foot of Mount 

 Pagus, near the Caravan Bridge (mentioned in the memoir of 

 Messrs. Strickland and Hamilton), and they contain crystals of a 

 mineral which appears to be garnet. These shales are 300 or 

 400 feet in thickness, and below them others which are indurated 

 are found in the valley above the hot baths. 



At the western base of Mount Corax is a low isthmus crossing 

 between the gulf of Smyrna and the bay of Sighajik, which sepa- 

 rates the mountain from the district of Vourla. The greater 

 part of the isthmus is an alluvium of gravel, covering the schist and 

 shales ; but on the opposite side of the isthmus these latter rocks 

 reappear, dipping at the same angle as in the foot of Mount 

 Corax (45° to W.N.W.), passing into a ridge of limestone, semi- 

 crystalline, and greatly resembling the limestone of the Two 

 Brothers ; the crystalline condition, however, being in neither case 

 due to any immediate contact with volcanic eruptions. The lime- 

 stone now continues throughout the promontory in peaks and ridges, 

 whose height varies from 1000 to nearly 4000 feet. Near the 

 shore, on the west side of the isthmus, rises one of these peaks, which 

 is sharp and conical, and crowned by an ancient fortress. On its 

 western base repose, in a horizontal position, compact white cal- 

 careous strata and greenish marls, identical with the fresh-water 

 deposits described by Messrs. Hamilton and Strickland as existing 

 in the vicinity of Smyrna. These deposits occupy a considerable 

 district round the modern town of Vourla, as well as in other parts 

 of the Promontory of Karabournou and the islands within the 

 gulf, and they are indicated in the map by the yellow colouring. 

 Of the lacustrine origin of this formation there is the fullest evi- 

 dence, from the number and variety of fresh-water shells which 

 are found imbedded in the different strata, and in the probably 

 contemporaneous fresh- water basins of the interior of Asia Minor. 

 In some localities the fossils are very abundant, as on the road to 

 Vourla, about two miles to the east of the town, and in the small 

 islands which form the anchorage of Vourla. 



