160 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



E. S.E., at an angle of from 45° to 60°, and, in both cases, pass be- 

 neath the intermediate mass of limestone which occupies the entire 

 district between them. The limestone is, in general, a grey compact 

 rock, but is sometimes crystalline, as, for instance, near Eitri, anc. 

 Erythrae, at a spot noticed by Mr. Hamilton. The crystalline con- 

 dition is probably due in this spot to the proximity of recent vol- 

 canic ejections of trachyte, &c, which occur abundantly in the 

 neighbourhood. 



In the western part of the Karabournou promontory are found 

 also igneous rocks of two periods, the one antecedent and the other 

 subsequent to the date of the lacustrine formations. The former 

 is presented in a hill of serpentine, several hundred feet in height, 

 near Cape Koumour Baba, the northern extremity of the promontory, 

 and upon its sides rest in undisturbed succession the parallel layers 

 of the several calcareous strata and marls deposited at the bottom 

 of the lake ; the shales in contact have been much disturbed and 

 altered, and are indurated into slate hardly distinguishable from 

 slates of the older rocks. The trap rocks of the latter period occur 

 in four localities, in each of which they differ in their mineral 

 composition : the first is found on the shore opposite to the Island 

 of Sahib, and its intrusion has evidently accompanied the disturb- 

 ance indicated by the considerable dip of the adjacent lacustrine 

 deposits. The trap contains numerous small drusy cavities, in 

 which is always found a singular fibrous mineral. 



The lacustrine deposits correspond exactly with those of Vourla 

 and of Smyrna, both in colour and mineral arrangement. In the 

 island of Sahib there are some good specimens of pisolite, inter- 

 stratified with the calcareous. portion of the deposit. 



Sahib Island. 



_j?7H 



The above section exhibits portions of the whole series of rocks 

 noticed in this paper. It illustrates the different ages of eruption 

 and deposition ; and commencing near the coast, about two miles 

 to the west of Cape Koumour Baba (marked A on the map), it 

 terminates at Sahib Island (marked B). 



The next trappean rock is a peaked mass protruding from 

 beneath the tertiary sediments at Cape Koumour Baba. These 

 rocks are much contorted at the point of contact, but with the ex- 

 ception of appearing a little more indurated, they are not other- 

 wise altered. 



The above diagram exhibits a section presented in the cliffs that 

 extend from the Cape about a mile to the westward, where their 



height is about 140 feet. 



