8 

 NIAGARA FALLS AND GORGE* 



(EXCURSION B 1.0 

 BY 



Frank Bursley Taylor. 



GENERAL RELATIONS OF THE NIAGARA 

 DISTRICT. 



NIAGARA DISTRICT DURING THE TIME OF THE LAST ICE SHEET. 



During the maximum extent of the last or Wisconsin 

 ice sheet, Niagara district lay under about 3,000 feet (900 

 m.) of ice and was in or near the axis of the main ice 

 current which moved southwestward through the basins of 

 Lakes Ontario and Erie. One of the most pronounced 

 re-entrants of the ice front at that time was at Salamanca, 

 N.Y., about 67 miles (107 km.) south of Niagara Falls. 

 The general level of the hills around Salamanca is 1,800 

 to 2,000 feet (550 to 600 m.) above sea level, and from 

 this place to Niagara Falls the surface of the ice rose 

 probably not less than 1,500 feet (450 m.). The altitude 

 of the general surface at Niagara Falls is nearly 600 feet 

 (182-9 m -) above sea level, indicating therefore, a thickness 

 of ice approximating 3,000 feet (900 m.). 



The Niagara district remained continuously under the 

 burden of ice, not only during the entire time that the 

 front of the ice sheet was retreating from a point about 

 10 miles (16 km.) north of the Ohio river at Cincinnati to 

 Niagara Falls, but during an equally long time, probably, 

 in the advancing phase. As the ice front retreated north- 

 eastward in the Lake Erie basin, glacial waters followed 

 it and covered the lower ground as fast as the ice with- 

 drew. For a short time after the ice had uncovered the 

 present site of Niagara gorge the lake waters still covered 

 this district, but when it had retreated to a position 

 probably about at the present shore of Lake Ontario 

 north of Lewiston, a lower outlet was opened on the north- 

 ward sloping hills south of Syracuse, N. Y., and the waters 



*The material for this Guide Book, so far as it relates to Niagara Falls and Gorge, 

 is taken mainly from the unpublished manuscript of the Niagara Folio, to be published 

 by the United States Geological Survey, and is used with the permission of the Director. 



(Mr. Taylor's text was written before the field and office studies were completed, 

 and he has had no opportunity of reading the proof. — Ed.) 



