GEOLOGY OF THE TBOAD. 629 



between the two extremes, having a distinctly schistose structure, and 

 being composed for the most part of olivine and talc, besides consider- 

 able quantities of pyroxene as well as other minerals not yet 

 determined. 



At various intervals throughout the zone of schistose rocks occur 

 rather coarsely crystalline white limestones. 



The structure of Mount Ida is a comparatively simple anticlinal, 

 with so short an axis extending east and west that the upper portion 

 of the mountain is approximately a dome. 



The highly crystalline stratified rocks are, perhaps, the chief 

 topographical determinants of that region. Their position and dis- 

 tribution indicate that, in the early stages of its development, the 

 peninsula of the Troad was represented by several islands which 

 furnished much of the detritus for subsequent formations. 



Intermediate Zone. — The rocks of the middle zone are for the 

 most part semicrystalline limestones, a very ferruginous quartz ite, 

 together with greenish, somewhat schistose, rocks, and others which 

 are, macroscopically, like argillites, but contain too large a proportion 

 of quartz. 



The limestone is generally compact, grey or reddish-coloured, very 

 like the Cretaceous (according to Prof. JSTeumayr) in the Acropolis at 

 Athens, and has often large quantities of silica so irregularly dis- 

 tributed as to produce a very rough weathered surface, like the Cre- 

 taceous limestone west of Smyrna. This limestone is found chiefly 

 about the base of Mt. Ida, at Edremit (Adramyti), near Dikelee- 

 dagh and Chaly-dagh, also between Quayalar and Ahmadja and 

 several kilometres south-west of llesfagy. At Cojekia-dagh (the 

 spur of Dikelee-dagh on which stand the remains of the ancient 

 Gargara) it is peculiar in containing many small acicular quartz 

 crystals. The ferruginous quartzite was observed in one locality 

 only. 



The greenish, somewhat schistose rocks, with sandstones of the 

 same colour, near Ahmadja, as west of Smyrna, overlie the limestone. 

 The Cretaceous age of the limestone at the locality last named appears 

 to be quite definitely determined by the observations of Strickland, 

 Tchihatcheff, and Spratt ; but the age of that near Ahmadja is yet 

 uncertain. Concerning the single fossil which has been found in it, 

 Prof, j^eumayr writes, it is diRliynclionella, which is so widely distri- 

 buted that it cannot be used as a certain means of determining 

 the age of the strata in which it occurs ; but the limestone is probably 

 Cretaceous. 



That these rocks are younger than those of the mica-schist zone 

 is indicated not only by the fact that they contain fossils and are 

 less crystalline than that group, but also by the fact that they are 

 made up of sediments derived from the crystalline schists. On the 

 other hand that they are, at least in part, old rocks is shown by the 

 contact-zone produced in them by the quartz-diorite. 



In 1881 Mr. Frank Calvert, American Consul at the Dardanelles, 

 discovered undoubtedly Eocene fossils (Nummulites determined by 

 Prof. Neumayr) at several places in the Troadic peninsula outside 



