354 E. HUNTINGTON — GLACIAL PERIOD IN NON-GLACIATED REGIONS 



permitted me to devote an iminterrupted year to the preparation of a 

 narrative of the journey in Chinese Turkestan, entitled "The Pulse of 

 Asia," and to the study of various climatic problems, some of which are 

 discussed in the following pages. 



Eelative Importance of Glaciation and of other Evidences of 



CLIMATIC Changes 



The investigations outlined above have led to the conclusion that some 

 of the most important criteria for the recognition of change of climate 

 have as yet largely escaped attention, because they occur in almost unin- 

 habited arid regions. In regard to the Pleistocene Glacial period — the 

 standard example of climatic change — the fact that the science of geology 

 has been studied chiefly in North America and Europe has naturally 

 given great prominence to the idea of glaciation, leaving other phases of 

 the subject comparatively unconsidered. It is a well established fact, 

 however, that, not only in glaciated regions, but in other parts of the 

 world as well, the Glacial period was preeminently a time of rapid cli- 

 matic changes. Everywhere the changes must have produced results of 

 some sort, even where there were no glaciers. It is to a study of these 

 results and of their significance that the present paper is directed. 



In North America and Europe, to restate a familiar fact, a tenth or 

 more of the land surface of the globe was covered with ice during the 

 Pleistocene period. A great glacial sheet scoured away the soil and rock, 

 scratched and rounded the hills, broadened the valleys, and deposited 

 hummocky moraines and plains of till. In other parts of the world 

 glaciation was limited to a few comparatively small mountainous areas. 

 There, as in the larger regions, the depth of snow on the ground in- 

 creased, because the temperature was lower or because the snowy precipi- 

 tation was greater tlian before. New glaciers were formed in the higher 

 valleys and old glaciers increased in size ; yet at a maximum the area cov- 

 ered by ice probably never exceeded 15 per cent of the land of the globe. 

 Moreover, glaciation was a feature of glacial epochs only, not of inter- 

 glacial epochs. Therefore we are warranted in saying that glaciation, 

 though extremely important, was only a local feature of the period to 

 which it has given a name. 



Typical Features of a Eiver in an arid Eegion 



1. glacial features 



An examination of a typical river in central Asia will illustrate the 

 manner in which the changes of climate of the Pleistocene period have 



