

Eocene Formations surrounding the Dardanelles. 415 
/£gean district into the Marmora, where they formed an archipelago 
in the Eocene Sea. 
The Eocene deposits surrounding these old rocks commence with 
sandstones, conglomerates, and clays, which become calcareous and 
nummulitic upward, and are about 2000 feet thick in the aggregate. 
They are succeeded by 3000 feet of lacustrine sandstones, clays, 
and schists, interstratified with volcanic rocks, and containing coal- 
seams. These beds have yielded Anthracotherium, plant-remains, 
and Corbicula semistriata at the coal-horizon, which is near the 
middle of the series. They are widely spread in Southern Thrace, 
and are cut off to the eastward by the falling-in of the Marmora 
sea-bed. The author has traced them along the Gallipoli Peninsula 
to Imbros Island,—Lemnos and Samothrake are partly composed 
of similar beds; and he considers that all these deposits represent 
the uppermost Eocene and the Oligocene, and that the coal-seams 
belong to the latter. 
The folding of the Lower Tertiary strata is plainly marked, and 
prolongs the direction of the Greek ‘flysch ’-deposits into the 
Marmora, forming basins in which the Miocene beds accumulated. 
There are three main folds, all passing east-north-eastward through 
the Eocene channel between the old rocks of Thrace and those of the 
Troad. The central fold developed farther eastward in post-Sarmatic 
times, rising into a ridge at Dohan Aslan, which dammed the outlet 
for the Marmora water fo the west, and was the proximate cause of 
the formation of the Bosphorus in the Pontic Period, and of the Dar- 
danelles at the end of the Pliocene. Volcanic eruptions were pro- 
longed irom Cretaceous to Miocene times in Thrace, Imbros, Lemnos, 
end Mitylene. Strati Island is entirely volcanic, and the greater 
part of Imbros also. 
Marine Miocene (Helvetian to Tortonian) deposits appear north 
of the Gulf of Xeros and in the Marmora, and are probably vestiges 
of a Lower Miocene sea-connection between the Ponto-Caspian and 
the Mediterranean. 
Sarmatic deposits, first freshwater, then marine, result from the 
development of a lake, with a narrow opening north-eastward to the 
Pontic area, which occupied a large portion of the district. The 
freshwater beds are still nearly horizontal in the Dardanelles, but 
are much dislocated along the northern shore of the Sea of Marmora, 
where they contain naphtha and lignite. The overiying marine 
(Macira) limestones fringe the freshwater beds as a shore-belt for 
30 miles along this coast, and extend through the Dardanelles to the 
Southern Troad. 
Brackish and freshwater Pontic strata occur in numerous detached 
lake-basins which drained north-eastward. The Bosphorus was 
probably cut by river-action through the rim of the lowest of these 
basins, on the recession of the Sarmatic Sea, and the A®gean drainage 
then passed into the large, closed, brackish lake described by 
Andrussov as occupying the Black-Sea area from the Pontic to the 
beginning of the Diluvial Period. 
The water-line of this sea-lake finally receded to nearly 200 feet 
below its present shore-line, when the Sea of Marmora stood about 
80 feet higher. Then the water began to rise again during the 
