CASPIAN SHORELINES NEAR KRASNOVODSK. 35
the processes of erosion had had a lower baselevel before the beaches were built; that is, the Caspian here as elsewhere rose upon the mountain flanks from a formerly lower level.
The more problematic cobble deposits near Krasnovodsk lie at altitudes of from 400 to 470 feet over the Caspian, in notches (NN, fig. 2o) on the steep southern face of the high escarpment, the Kuba Dagh, formed of vertical Jurassic limestones, whose sharp points rise 600 or i,000 feet above the sea. There can be little doubt that the well-rounded cobbles and bowlders, from 2 to 5 feet in diameter, indicate wave action, but it is not clear when the wave action took place. A curious feature is the occurrence with the cobbles of subangular scraps of dark crystalline rock, up to 5 or 6 inches in diameter, apparently derived from the crystalline ridge at the
Fig. 21.—An Elevated Caspian Shoreline in the Balkhan Mountains, near Jebel Station, Central Asiatic Railway.
end of the tombolos, although a mile of low land now separates the ridge from the Kuba Dagh. It is eminently possible that the cobbles should be associated with the horizontal marls and limestones, Andrussow's " Aktschlagylschichten," a section of which we saw on the caravan route to Khiva on the north side of the Kuba Dagh, uncomformably overlying its vertical layers, as in fig. zo ; and if so, they would be much older than the modern Caspian shorelines that we were looking for.
The only safe test to apply to these cobble beds, as well as to those in the boo-foot spits near Baku, will be to search for them at other points where the coast is high enough to have received similar marks. If we provisionally accept the Baku spits as marking a temporary shoreline, it is possible that much of their exceptional height may be due to relatively local warping. Such a supposition is not inherently