586. W. J. Hamilton, Esq., on the 



E. and F. — The lower of these beds is a soft, purplish white, trachytic rock, and passes upwards 

 insensibly into F, which is harder and generally whiter. They both contain zeolites and crystals 

 of olivine and hornblende, and apparently a few plates of mica. 



The cliff of this table-land presents, in many places, slight indications of 

 perpendicular cleavage, but the lines are not sufficiently marked to warrant 

 the rock being considered columnar. The slope of the hill below the cliff, 

 towards the W. and S.W., is covered with enormous masses of the upper, 

 harder beds, which have fallen in consequence of the crumbling of the softer 

 sandstone below. They extend to some distance, and as many of them have 

 been derived from the very centre of the mass, they show the real structure 

 of the beds much better than specimens obtained from the summit of the hill, 

 where the rock has been long exposed to atmospheric influences. 



A little to the east of Section 4, are very large fragments (in some places 

 quite en masse) of the capping of the table-land, as if broken and let down by 

 an earthquake or some great subsidence of the valley. 



Still further eastward, the valley is suddenly terminated by a hill, or mass 

 of very coarse trachytic and porphyritic conglomerate, stretching across from 

 Hassan Dagh to the north ; and it will be seen by Section 1, that the red and 

 yellow sandstones and conglomerates repose upon this trachytic conglomerate, 

 which, therefore, belongs to a much more ancient volcanic eruption than the 

 white pumiceous capping just described. Notwithstanding the present ap- 

 parently exhausted state of the great volcanic mountain Hassan Dagh, what a 

 variety of epochs of activity, extending through a period the duration of which 

 it is impossible to calculate, is laid open in the few preceding observations ! 



Istly. We have the epoch when these huge trachytic bowlders were thrown 

 out; and whether they were brought into their present situation by direct 

 ejection from the crater, or were washed down by currents from the breakings 

 up of pre-existing trachytes, they bear witness to very early volcanic opera- 

 tion as respects this part of the globe. 



2ndly. The epoch when the red and yellow sands and grits, and sandstone 

 conglomerates, and marls were deposited upon these trachytic conglomerates, 

 — a formation which, without attempting to fix its contemporaneity, I consider 

 as nearly equivalent to our new red sandstone ; at all events it belongs to the 

 saliferous deposits of AsiaMinor. 



Srdly. The epoch when the extensive volcanic capping of the table-lands 

 was poured or showered forth from the neighbouring mountain. This makes 

 the second period of volcanic activity. It is impossible to state the extent of 

 this formation, which ranges solely towards the N. and N.E.; I believe it may 



