RE-ADVANCES OF THE ICE-SHEET. 345 



prominence is due to the preglacial contour of the bed-rocks. From Big 

 creek westward, the Leipsic shore displays perhaps three or four times 

 more wave-cutting and resultant beach gravel and sand than in the vicin- 

 ity of Brooklyn and east of the Cuyahoga valley. There, however, it is 

 unmistakably continued northeastward beyond the more northern de- 

 posits of the Newburg moraine, so that the later part of the Leipsic shore 

 work was done after the ice sheet had receded from its Newburg boundary. 

 The stages of recession of the ice contemporaneous with the Belmore 

 and lower beaches are recorded by moraines, as mapped by Leverett, 

 passing from west to east and southeast near Hamburg and Lockport, 

 N. Y., from which they may be conveniently named, the Hamburg 

 moraine and the Belmore or Sheridan beach, and later the Lockport 

 moraine and the Crittenden beaches, being respectively correlative. No 

 well defined shore of lake Warren is found below the Euclid Avenue or 

 principal Crittenden beach. 



Temporary Re-advances of the Ice-sheet. 

 at the mouth of rocky river and in cleveland. 



With the descriptions of drift sections already given, only a few words 

 are needed here to direct attention to the clear evidence of a temporary 

 re-advance, interrupting the general departure of the ice, shown by the 

 relations of the series of glacial and modified drift formations in Cleve- 

 land and its vicinity. Apparently just before the accumulation of the 

 Newburg moraine, the ice border for a short time moved forward over a 

 tract which it had just previously relinquished, forming by this re-advance 

 the uppermost deposit of till in the old valley of the Rocky river and on 

 East Clark avenue and southward in Cleveland. The Rocky river section 

 indicates that the fluctuating ice-front was all the while bounded there 

 by the glacial lake. - 



AT TORONTO AND SCARBORO', ONTARIO. 



About 160 to 170 miles northeast from Cleveland the deposits of glacial 

 and modified drift and alluvium in Toronto and Scarboro', Ontario, as 

 described by Prof. A. P. Coleman,^ record a more complex history of 

 glacial re-advance during the time of general retreat. Studying the sec- 

 tions of till and interglacial fossiliferous beds given by Coleman, with their 

 evidences of stream erosion before the deposition of the till next above 

 the thick stratified sand and clay which contain remains of a temperate 



*Am. Geologist, vol. xiii, pp. 85-95, February, 1891 ; Journal of Geology, vol. iii, pp. 62i-645, with 

 sections, September-October, 1895. 



