THE INTERGLACIAL GORGES OF SIX MILE CREEK AT 

 ITHACA, NEW YORK 



JOHN LYON RICH and EDWIN A. FILMER 



University of Illinois 



INTRODUCTION 



The question of the complexity of the glacial period in central 

 New York is still largely unsettled. It is conceded probably by 

 aU that the region has suffered more than a single ice invasion, but 

 how many such invasions there were and how far the different 

 invasions were separated from each other in time are problems as 

 yet only partially solved. 



The criteria for the identification of distinct glacial epochs 

 which can be applied in a hilly region well within the southern 

 limits of the ice, and even within the zone of active erosion by the 

 latest Wisconsin ice sheet, are necessarily different from those which 

 have been used so extensively and so successfully in the Mississippi 

 Valley. Under the conditions prevailing in central New York one 

 could not expect, for instance, to find drift sheets imbricated in the 

 same manner as on the plains of the Mississippi near the limit 

 of glaciation where the erosive power of the ice was doubtless 

 sHght and undirected and where deposition was the rule. Nor 

 would it be possible to apply the common test of the relative erosion 

 suffered by drift sheets of different ages, for, since the region in 

 question lies within the great moraines of the Late Wisconsin epoch, 

 any erosional features developed on earHer drift sheets would have 

 been modified or destroyed by the Wisconsin ice. The hilly nature 

 of the country, too, would tend to prevent the accumulation of till 

 in even, continuous sheets and would lead to an irregular, patchy 

 distribution of any remnants of earlier drift deposits. The meager- 

 ness, in this region, of the evidences from glacial deposits indicating 

 multiple glaciation may be judged from the fact that, so far as the 

 writer has been able to discover, only one investigator, Carney,^ has 



' " Pre-Wisconsin Drift in the Finger Lake Region of New York." Jour. GeoL, 



XV (1907), 571-85. 



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