1849.] HAMILTON ON THE GEOLOGY OF ASIA MINOR. 375 



of white earthy limestone which there contains a few beds of flint 

 both tabular and in nodules. 



3. Aralo-Caspian Formationi 



Another tertiary formation remains to be described, although from 

 its isolated position, it is impossible to determine its exact relations 

 to the nummulitic and gypseous deposits of the Halys, from which it 

 is separated by the intervening range of the Jurassic and cretaceous 

 deposits. It occurs on the promontory of Sinope, and forms the crest of 

 the hill to the north-east of the Greek town (see fig. 1). Here are first 

 seen thin horizontal beds of a loose calcareous sand intermixed with, and 

 overlaid by, hard beds of limestone with a few impressions of shells. 

 This is again overlaid by a bed of shelly limestone twenty or thirty 

 feet thick entirely made up of bivalve shells. The different parts of 

 the bed differ somewhat in consistency, and the shells are in different 

 degrees of preservation, some being hollow and crumbling, while 

 others are more filled up. They appear to belong chiefly to the 

 genera Cyrena and Cardium. Above this shelly limestone is a hard 

 compact calcareous rock, without fossils, but conformably stratified 

 to those beneath. These beds, and particularly that of shelly lime- 

 stone, had been extensively quarried by the ancient inhabitants, as 

 appeared from the quarries themselves, and the numerous blocks 

 occurring amongst the ancient ruins. 



It was after an inspection of these fossils by Prof. E. Forbes soon 

 after my return to England, that Sir R. Murchison inserted suggest- 

 ively in his Map of Russia and the surrounding lands, that the lime- 

 stone of Sinope might prove to be a remnant of his large Aralo-Cas- 

 pian brackish deposit ; and I may here observe, that another instance 

 of the same deposit occurs further to the east at Platana, a few miles 

 to the west of Trebizond. Whether this conjecture be correct or not, 

 or whether this formation ought rather to be connected with the 

 older and purely marine miocene limestone of Southern Russia, more 

 accurate researches can alone determine. The Sinope limestone may 

 possibly indicate a transition from one of these conditions to the other. 



4. White Lacustrine Limestone with Freshwater Shells. 



It only remains for me to say a few words respecting the forma- 

 tion of white earthy, marly limestone which occupies such an exten- 

 sive area in the centre of Asia Minor, and which I believe to be the 

 most recent of all its formations. It has not inaptly been already 

 called a lacustrine formation, and has been described by Mr. Strick- 

 land and myself as occurriug in large masses in many of the valleys of 

 Western Anatolia. It overlies that portion which I have described 

 near Sevrihissar as containing selenite, and extends south of Angora 

 and Sevrihissar into the great central district of the Haimaneh, a 

 district corresponding in great measure with the Axylus or woodless 

 country of the ancient geographers (see Strabo) . It contains in a few 

 j)laces freshwater fossils, amongst which Planorbis, Limncea and Palu- 

 dina are the most frequent. It occasionally contains nodules of flint. 



