REVIEW OF OLD AND NEW STANDARDS OF PLEISTOCENE DIVISION 420 



One should then admit, in order to explain the passing of the fauna of 

 cold mammals into England, the existence of a phase of marine regression 

 | H. P. 0., ? coastal elevation] which might have taken place, say, at the 

 beginning of the Monastirian, or perhaps at the end of the Monastirmn. 

 It is this last point of view that Barrois (1897.1) has adopted in estab- 

 lishing the distribution of clay (limon) in Brittany; this clay (limon), 

 which is later than the "elevated banks," extends on the littoral islands 

 contained inside the curve of 25 meters of marine depth. Barrois 

 admits that in this epoch the English Channel was transformed into a 

 fluvial vallev, with the waters flowing to the west. In this valley, and 

 on one side or the other of the Pas de Calais, gravels were deposited 

 which contain remains of the mammoth and of Rhinoceros tichorhinus, 

 now dredged from the bottom of the English Channel and the Dogger 

 Bank in the Xorth Sea. Then a very recent new marine transgression 

 [H. F. 0., ? coastal depression] intervened causing the isthmus of the 

 Pas de Calais to disappear definitely. 



Relation of terraces to moraines. — Deperet follows with a considera- 

 tion of the northern coasts of France. After reviewing (1919.1) the 

 work of Geikie, Penck and Bruckner, and his own observations in the 

 Alps and Pyrenees (as tabulated on page 414), and after considering the 

 evidence afforded by moraines and river terraces, he gives the following 

 generalization : 



I intend above all to establish a constant relation between the frontal 

 moraines of each glaciation and the relative altitude of the fluvial terraces 

 which came from them. The external moraines are related to the 55-60- 

 meter terraces; the intermediary moraines to the 30-meter terraces; the 

 internal moraines to the 18-20-meter terraces. Following each glaciation 

 is a distinct erosion period of the valleys by great floods of water issuing 

 from the glaciers. 



This moraine-terrace relation establishes a general principle applicable 

 to the glaciers emptying into the Atlantic and Mediterranean valleys, 

 which Deperet also extends to the great glaciers of the north of Europe. 

 observing that this precise method of comparative determination of 

 Quaternary glaciers by the altitude of the corresponding flu rial terraces 

 was noted by Penck and Bruckner in their magnificent work on the 

 glaciation of the Alps, but that the constant relation of the terraces and 

 respective elevations were not established by them. [In figure 2, Doctor 

 Reeds has assembled a series of cross-section profiles to illustrate the 

 relations of the various Alpine glaciations to the river terraces of the 

 Alpine foreland and the marine terraces of the Mediterranean.] Taking 



