Vol. 60.] LATER FORMATIONS SURROUNDING THE DARDANELLES. 251 



lacustrine, is very plainly developed, and follows a north-east-by- 

 easterly direction through the Eocene channel between the old rocks 

 of Thrace and those of the Troad. The central fold can be traced, 

 in nearly a straight line north 60° east, for 200 miles from the 

 islands of Skiatbo and Skopelo in the Maguesian group, through 

 Lemnos, Imbros, and the north-western coast of the Gallipoli Penin- 

 sula, until abreast of Ibridji, in the Gulf of Xeros. This direction 

 of folding of the Lower Tertiary strata accords with that shown 

 by Prof. Philippson (14, map) for the ■ flysch ' of Thessaly, which 

 is described by Hilber as Oligocene and as containing coal-seams 

 (13, p. 621). 



F. von Hochstetter considered that the higher ridges of the 

 Gallipoli Peninsula consist probably of clay-slate (phyllit), and 

 that the Xummulitic Limestone in Thrace lies generally horizontal, 

 showing only local disturbances (2, pp. 389, 409). These con- 

 clusions are not borne out by the facts which 1 have observed : 

 the Xummulitic and Oligocene rocks are dislocated 

 and folded on a large scale, and form basins in which 

 the Helvetian and later deposits were laid down. 



The Lower Tertiary lake had a coast-line in Thrace little differing 

 from that of the Xummulitic sea, but probably transgressing some- 

 what more in places over the older rocks ; as, for example, in the 

 south-eastern part of Samothrake, where the sandstones and volcanic 

 tuffs lie directly upon old clay-slates (5, p. 11). Its waters 

 reached certainly to Lemnos in the west, and to Kodosto in the 

 east, possibly even farther eastward, as Viquesnel mentions sand- 

 stones with carbonized plant-impressions from Buyuk Tchekmedje 

 to Silivri. on the northern shore of the Sea of Marmora 

 (3, p. 310). 



A reference to Pis. XXI & XXII will show that the strikes and 

 dips of the Lower Tertiary strata surrounding the Dardanelles 

 result from three main foldings, of which the northernmost 

 intersects the island of Samothrake, where the Xummulitic strata dip 

 north-westward and westward in the western portion of the island, 

 and eastward in the south-eastern corner. This fold forms the 

 eastern portion of the northern boundary of the North iEgean 

 depression ; thence, passing inland, it shows in the anticlinal ridge 

 of the Kuru Dagh. It is continued, through the Tekfur-Dagh ridge, 

 nearly to Pvodosto, and thence eastward forms the northern boundary 

 of the Marmora depression. Pig. 2 (p. 252) shows the appearance 

 of the vertical Oligocene strata at Combos near Rodosto, with the 

 horizontal Miocene terraces overlying them unconformably. 



The folding which follows the southern shore-line of the 

 Eocene channel between Thrace and the Troad enters the district 

 in a nearly north-and-south line at Mitylene (10, p. 428), passes 

 through the Troad in a north -north -easterly direction, curving 

 north-eastward, and skirts the old rocks at Gueredje, where the 

 Lower Tertiary lacustrine deposits dip 45° north-north-westward. 

 From this place it runs as a fault with a north-north-westerly 

 downthrow along the southern shore of the Sea of Marmora, past 



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