of the Neighbourhood of Smyrna. 397 



southern border, they overlie the lacustrine limestone and marl of the Plain of 

 Sedikeui. The boundary of the two formations is well defined, the trachyte 

 terminating abruptly, with a steep slope, like the margin of a modern lava 

 coulee. A stratum of pumiceous tufa is commonly interposed, between the 

 trachyte and the lacustrine strata. The uppermost bed of the latter is a con- 

 glomerate of rounded pebbles of quart/, hippurite limestone, and schist, but 

 not the least trace of any igneous rock is discoverable in it. Beneath this bed 

 are calcareous marls, containing Planorbes and other fresh-water shells, and 

 passing downwards into white limestone. 



The absence of igneous products in the conglomerate proves the sudden 

 eruption of the trachyte which reposes on it; yet it is possible that this bed of 

 transported pebbles may be connected with that event. Earthquakes pre- 

 ceding the eruption may have caused currents in the lake, which would wash 

 these rolled pebbles from its gravelly margin into its central parts, and termi- 

 nate that long period of repose, during which the subjacent marls and lime- 

 stones were deposited. 



The highest point attained by the trachyte is about 3 miles S.W. from 

 Smyrna, near the valley which separates these rocks from the Corax range. 

 The view from this eminence proves how much the picturesque and botanical 

 features of a country depend on its geology. On the south is the vast, undu- 

 lating plain of lacustrine limestone and marl, the greater part of which is 

 cultivated and interspersed with villages. On the west, the decomposing sand- 

 stone and shale of Corax form a cluster of conical mountains thickly covered 

 by evergreen shrubs. In the east, the view is terminated by Mount Tartali, 

 where the compact gray hippurite limestone forms crags and precipices, with 

 fir and other trees sparingly scattered among them. Lastly, the trachytic 

 rocks in the foreground produce neither trees nor shrubs, but present innu- 

 merable masses of naked rock, jutting through a fine green turf, adapted 

 only for pasturage. 



Having now given a general sketch of the sedimentary and volcanic rocks 

 which occur near Smyrna, 1 will introduce a more detailed account of Mount 

 Pagus, where several of them are brought to view within a very small space. 

 (Plate XXXII., Sec. Nos. 1 and 2.) 



The hill anciently called Pagus rises immediately to the south of the mo- 

 dern town of Smyrna. It forms the north-eastern extremity of the mass of 

 trachytic rocks above described ; and a deep ravine separates it on the east 

 and south from the plateau of lacustrine deposits^ whose drainage produces 

 the classic river Meles, which escapes into the sea through this ravine. 



The height of Mount Pagus may be estimated at about 500 feet. It is 

 principally composed of trachyte and trachytic conglomerate, which on the 



3f2 



