236 ANNALS NEW YORK ACADEMY OF SCIENCES 



Relative r r _ t „,„ Descent of 

 duration lolMS snow ij ne . 



Units Years Years Meters 



Postglacial, post-Wiirm hemicycle. . . 1 20,000 20,000 



IV or Wvsm Glaciation 1 20,000 40,000 1,200 



3rd or Riss-Wiirm Interglacial Stage. 3 60,000 100,000 



III or Riss Glaciation 1 20,000 120,000 1,250 



2nd or Mindel-Riss Interglacial Stage 12 240,000 360,000 



II or Mindel Glaciation 1 20,000 380,000 1,300 



1st or Giinz-Mindel Interglacial Stage 5 100,000 480,000 



I or Gunz Glaciation 1 20,000 520,000 1,200 



The three chief conclusions of Penck are as follows: 



1. If the whole Ice Age extended over a period of 500,000 to 1,000,000 

 years, the Second very long warm Interglacial Stage, also known as the 

 Mindel-Riss or Helvetian, is reckoned at more than 200,000 years, while 

 the final relatively short interglacial stage, the Riss-Wiirm, is reckoned 

 at 60,000-100,000 years. 



2. The duration of the Lower Palaeolithic culture periods, the pre- 

 Chellean, Chellean and Mousterian, would by this reckoning be much 

 longer than that of the Upper Palaeolithic culture periods, the Aurig- 

 nacian, Solutrean and Magdalenian. Penck estimates that since the be- 

 ginning of Magdalenian times 24,000 years may have elapsed and since 

 its close about 16,000 years. 



3. Compared with these prolonged Palaeolithic divisions the Neolithic 

 Stone and Metal periods have occupied an almost unappreciable length 

 of time. If the beginning of the Neolithic lake dwellings is dated about 

 5,000 to 7,000 years ago we estimate that the beginning of the Copper 

 Age in Europe dates back between 3,000 and 3,500 years; in Africa it is 

 much more ancient. 



The human culture stages are arranged above not according to Penck 

 but according to the more recent correlations of Obermaier, Breuil, 

 Schmidt and others. 



GEOLOGIC AGE OF THE CULTURE STAGES 



The trend of Palaeolithic research lately has been to draw all the 

 human culture periods from the pre-Chellean to the Magdalenian closer 

 together and to reduce the time assigned for their evolution. All the 

 French authorities, led by Boule, Cartailhac, Breuil and Obermaier, are 

 now agreed in assigning the earlier Palaeolithic cultures, the pre-Chel- 

 lean, Chellean and Acheulean, to the Third Interglacial Stage and not to 

 the Second. Schmidt has also lately declared himself in favor of this 

 view after a mlost exhaustive and valuable investigation of this problem. 



