within a Narrow Area. 173 



a lower series of marginal channels on Davies Hill 

 conducted the water southward into the Owego Valley. 



The development of the marginal channel on the south- 

 western slope of Rowe Hill marks a third stage in the 

 ice retreat (fig. 10). The lobe occupying the present 

 Gravel Creek Valley had now been melted back below the 

 divide between Gravel and West Sixmile Valleys and 

 thereafter the drainage was conducted around the south- 

 ern end of Rowe Hill into the East Sixmile Valley and 

 from thence into Owego Creek, utilizing probably the 

 lower of the marginal channels near the southwestern 

 base of Davies Hill. 



The postglacial topography and drainage is repre- 

 sented in fig. 11. 



A comparison of figs. 7 and 11 will give some notion of 

 the great modifications in both topography and drainage 

 that apparently have been occasioned by the occupation 

 of the Upper Sixmile region by the Pleistocene ice. To 

 some extent the readjustment of the streams and the 

 development of new topographic features is due to the 

 effects of ice erosion, but in a much greater degree to 

 the massiveness and frequency of the moraine deposits 

 of various kinds. 



It is the object of this paper to indicate how great may 

 be the changes which can be brought about by such pro- 

 cesses operating within a very restricted area as a result 

 of ice occupation, and to emphasize the importance of 

 glaciation in the moulding of the topography of the land 

 surface. 



BIBLIOGRAPHY. 



1. Filmer, E. A., The Interglacial Gorges of the Typical Hanging Valley 



of Sixmile Creek, Thesis, Cornell University, 1912. 



2. Williams, H. S., Tarr, R. S., and Kindle, E. M., Watkins Glen-Catatonk 

 Folio, Geol. Atlas of the U. S., Folio 169. 



3. Lockhead, W., Preglaeial Drainage of the Upper Cayuga Basin, Thesis, 

 M.S. Cornell University, 1895. 



4. Eich, J. L., Marginal Glacial Drainage Features in the Finger Lake 

 Region, Jour. Geol., vol. 16, p. 527, 1908. 



5. Rich, J. L., and Filmer, E. A., The Interglacial Gorges of Sixmile Creek 

 at Ithaca, New York, Jour. Geol., vol. 23, p. 59, 1915. 



6. Tarr, R. S., Physical Geography of New York State, Part V. Rivers 

 of New York, Bull. Am. Soc, vol. 32, Dec, 189S. 



Physiographic Laboratory, Cornell University. 



