REVIEW OF OLD AND NEAV STANDARDS OF PLEISTOCENE DIVISION 415 



2. PERI-ALPINE TIME STANDARDS OF PENCK AND BRUCKNER, AS 

 INTERPRETED BY DEPMIET 



Adoption of Theory of four glacial Advances 



We may now give an abstract from the observations of Deperet (1918- 

 1921) in their points of agreement and disagreement with the classic 

 observations of Penck and Briickner (1901-1909). We give a fuller 

 exposition of Deperet's work, beginning on page 422 of the present paper. 

 The square brackets indicate interpolations or comments by the 



present authors. 



First, it is interesting to observe that Deperet and Mayet adopt the 

 theory of four glacial advances, maintained by Penck and Bruckner, in 

 Europe. We refer to two recent papers by one of Deperet's former 

 students and present colleagues, Dr. Lucien Mayet, of Lyons (1921.1, 

 1921.2), from which we may make extensive citations, since he has set 

 forth the Penck and the Deperet standards with the clearness, precision, 

 and brevity characteristic of French scientific writers in general. 



As Mayet observes (1921.2, page 482), it is not necessary to review 

 the work of glaciologists of the last half century — for example, the 

 publications of Falsan and Chantre, who limited the Alpine glaciers to 

 a single great extension, in contrast to the pioneer, Geikie, who main- 

 tained six glacial periods and five interglacial phases. One of the 

 distinguished French paleontologists, Marcellin Boule (1921.1), recog- 

 nizes only three main glacial periods, the first of which is placed in 

 Pliocene time (see Table VIII). 



The researches of Du Pasquier, of Penck and Bruckner, of Deperet, 

 and of Kilian on the peri- Alpine region (see figure 1) relate to the 

 •fluvio-glacial complexes, their morainal formations (vallum, amphi- 

 theatres, etcetera 5 ), their layers of transitional alluvium (cones de tran- 

 sition et terrasses constituant celles-ci). In the valleys of this same 

 peri-Alpine zone one observes a self-staged series of terraces. The 

 highest above the present stream-bed belong to the external moraines 

 (those most remote from the central Alpine massif), which mark the 

 maximum of glacial extension and are the most ancient; also the lowest 

 terraces, which approach most closely the actual level of the existing 

 rivers and are related to the internal moraines (that is, moraines within 

 the preceding, nearer the central Alpine massif), which testify to a less 

 extension of the glaciers and are more recent in age. Similar observa- 

 tions may be made, with perhaps even more precision, in oertain valleys 

 of the Pyrenees. 



Vallon = dale; <nii pit ith raters = cirques. 



