REVIEW OF OLD AND NEW STANDARDS OF PLEISTOCENE DIVISION 413 



I. Old and new Standards of Pleistocene Division 



INTRODUCTION 



A matter of supreme human interest in anthropology at the present 

 time is the appearance of man in the successive stages of the geologic 

 history of Eurasia and of Africa. The chief object of the present paper 

 is to submit a summary and synthesis of the most recent interpretations 

 in the European Quaternary, both in their bearing on the prehistory of 

 man and as time standards of importance to students of American 

 Pleistocene geology and physiography. The recent coordinations of 

 Deperet have set a new basis of time division for the whole Quaternary. 

 The researches of De Geer establish the past fifteen millennia. When 

 combined they support, with certain modifications, the pioneer work of 

 Penck and Bruckner. This paper opens with a review of the progress 

 of opinion from 1901 to 1921 ; it presents a precise statement of Deperet' s 

 contributions of 1918 to 1921 and of De Geer's contributions of 1910 

 to 1921. The manuscript is entirely the work of the senior author. The 

 maps and synthetic diagrams are entirely the work of the junior author. 3 



In 1915 the senior author 4 published his "Review of the Pleistocene" 

 (Osborn, 1915.1), and in November of the same year his "Men of the 

 Old Stone Age" (Osborn, 1915.2), in which the existing knowledge of 

 Pleistocene chronology was reviewed and more or less precisely sum- 

 marized. At the same time the junior author prepared a number of maps 

 and diagrams graphically presenting the chronology of Penck and 

 Bruckner. Since 1915 great progress has been made in anthropology; 

 also an original and important contribution to the theoretic division of 

 the Quaternary has been made by the distinguished French geologist and 

 paleontologist, Charles Deperet, of the University of Lyons (Deperet, 

 1918. 1-.5, 1919.1, 1920.1, .2, 1921.1), to whom we were previously in- 

 debted (1908.1-.3, 1909.1) for the most satisfactory subdivision of the 

 Tertiary of western Europe, analyzed and extended by Osborn (Osborn, 

 1910.1). 



The historic bases of Pleistocene subdivision have been the following: 



(1) Astronomic: as in the studies of Croll (Croll, 1875.1), Wallace (1880), 

 and others. 



3 Both the preliminary and the final manuscript have heen submitted to Mr. Frank 

 Leverett and valuable annotations and corrections have been made at his suggestion. 

 He is not disposed to favor the substitution of the Deperet standard for that of the 

 Penck-Bruckner, not at least until it has been given careful field confirmation. 



4 This is the sixteenth contribution of the same author to the geologic and faunal rela- 

 tions of Europe and America, the previous papers being listed in the Bibliography of 

 Henry Fairfield Osborn, 1877-1915, p. 25 (1916.1). 



