MARILLA MORAINE. 688 



RELATION TO LAKE WHITTLESET 



This moraine seems to have been formed nearly at the time when the 

 lake level dropped from the Belmore beach to the Forest, and marks, 

 therefore, the closing part of the existence of Lake Whittlesey. Taylor and 

 the writer, after ti-acing the Belmore beach to Marilla, searched in vain for 

 its continuation on the north slope of the Marilla moraine. That slope 

 appears not to be modified by lake waves at the level of the Belmore beach. 

 This matter is considered more fully in connection with the discussion of 

 the Belmore beach. 



OUTER BORDER DRAINAGE. 



Along- the south border of the western portion of the moraine, from 

 southwestern Darien Township, in Grenesee County, to the end of the 

 moraine, near Marilla, there is an open valley occupied in part by an 

 eastern tributary of Cayuga Creek, in part by Little Buffalo Creek, and 

 in part abandoned. It shows a perceptible westward descent, and was 

 evidently utilized by the glacial waters in their escape to the lake, if it was 

 not opened by them. The width ranges from about one-fourth mile up to 

 over one-half mile. The banks are usually low, being seldom more than 

 30 feet in height. At Marilla it is a few feet lower than the Belmore 

 beach, and the valley continues descending westward till it reaches the level 

 of the Forest beach, where an extensive delta is found that covers the 

 interval between Little Buffalo and Buffalo creeks. It seems evident that 

 by the time this channel was fully opened the lake level had dropped to the 

 Forest beach and Lake Warren had succeeded Lake Whittlesey in the 

 Erie Basin. 



From the head of the eastern tributary of Cayuga Creek, just referred 

 to, eastward to Tonawanda Creek the line or lines of escape for glacial 

 waters have not been clearly worked out. There are scourways among 

 the glacial ridges and knolls in northern Darien Township which appear to 

 mark lines of discharge, and which may, by detailed study, be found to 

 form a coimected system. These may, however, have been opened at the 

 time the ice sheet was forming the Alden moraine, which, as above noted, 

 is combined with the Hamburg from Darien Township eastward. This 

 being the case, they do not throw light on the earlier part of the drainage. 

 From eastern Darien Township eastward to Tonawanda Creek there is a 

 sag or valley along the outer border of the moraine, which received some 



