Brooks, C. E. P. “The correlation of the Quaternary deposits of the British Isles with those of the continent of Europe.” Ann. Rep. Smithsonian Inst., 1917, pp. 277-375. [Full list of references.]
Penck, A., and Brückner, E. “Die Alpen in Eiszeitalter.” 3 Vols. Leipzig, 1901-9.
Gagel, C. “Die Beweise für eine mehrfache Vereisung Norddeutschlands in diluvialer Zeit.” Geol. Rundschau, 4, 1913, p. 39.
Wahnschaffe, F. “Die Oberflächengestaltung des norddeutschen Flachlandes.” Stuttgart, 1910.
Svastos, R. “Le postglaciare dans l’Europe centrale du nord et orientale.” Ann. Sci. Univ. Jassy, 4, 1908, p. 48.
CHAPTER VI
THE MEDITERRANEAN REGIONS DURING THE GLACIAL PERIOD
Our knowledge of the history of the Mediterranean basin during the Glacial period is not nearly so complete as is that of the more northern regions, chiefly for the reason that during most of the period the land lay above its present level, and except for local glaciers in the mountain regions there was no ice to leave us a record of the changing climates. Most of what we do know relates to the relatively brief periods of submergence.
At the beginning of the Glacial period the sea lay some 500 feet above its present level, and we can trace the first appearance of a northern marine fauna. This stage is known as the Calabrian; it is divided into two horizons—a lower, in which northern forms are still rare, and an upper, in which they are becoming abundant. The most typical species are two mollusca whose present habitat is the coast of Iceland—Chlamys (Pecten) islandicus and Cyprina islandica.