This ocean, already diminished in area, retreated after Oligocene times from the Iranian plateau, Turkestan, Asia Minor and the region of the north-west Alps.
This includes the Aegean and the Black Sea, and its margin skirts the south coast of Asia Minor.
Another bank i ioo fathoms from the surface runs south from the east end of Crete, separating the Pola Deep from the depths of the Levant basin, in which a depth of 1960 fathoms was recorded near Makri on the coast of Asia Minor.
Its safety also was secured by the barrier of rugged mountains (7000 to 8000 ft.) which separates its district from the rest of Asia Minor.
So complete is the watershed that no streams pass through these ranges, and there is hardly any communication in this direction between the interior of Asia Minor and the coast.
