208 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



The headwatei' portion of Oatka Creek is in the midst of morainic 

 knolls and ridges which conceal the preglacial features as fai* north as the 

 vicinity of "Warsaw. Here is entered an old valley, one-half to three-fourths 

 mile in width, which leads northward through elevated uplands into the 

 Ljwer tract lying between the Corniferons and Niagara escarpments. The 

 stream now turns eastward near Leroy and joins the Genesee, but the 

 preglacial channel probably continued northward. The course of the pre- 

 glacial channel is certainly not coincident with that of the present stream 

 even above the deflection near Leroy, for the latter flows on rock ledges 

 and has an important waterfall, known as "Buttermilk Falls," just north 

 of that village. Because of the great filling of drift north of Leroy, it will 

 be difficult to determine the course of the preglacial line. 



It is thought by Fairchild that several of the tributaries of the Genesee 

 held small glacial lakes at higher levels than the lakes in the neighboring 

 portions of the Genesee Valley. One in the valley of Knight Creek had 

 an outlet from its head westward past Bolivar. The evidence of a discharge 

 across the col at the head of this valley is clear. The altitude is so great 

 that it can not have been the discharge for the Genesee glacial lake. 

 There is equally clear evidence of the westward discharge of a small gla- 

 cial lake in Van Campens Creek Valley along a line utilized by the Erie 

 Railroad. There is a well-defined scourway across the present divide at an 

 altitude of 1,692 feet, which is nearly 100 feet higher than the westward 

 outlet of the Genesee Lake into Honeoye Creek, a few miles to the south. 

 This valley carries terraces at different levels, which are thought by Fair- 

 child to harmonize in some cases with the local glacial lake outlet and in 

 others with the outlets for the Genesee waters at 1,600 and 1,496 feet 

 The morainal lake in Caneadea Creek Valley was probably preceded by a 

 glacial lake, though the outlet of the latter was not determined. A glacial 

 lake in Oatka Creek Valley is found by Fairchild to have first discharged 

 southeastward, past the sites of Silver Springs and Castile, to the Genesee 

 Lake, the altitude of the head of the channel being about 1,400 feet. With 

 the retreat of the ice bamer this lake eventually found a line of northwest- 

 ward discharge at an altitude about 100 feet lower, through a valley in which 

 the villages of Dale and Linden stand, and thence across a pass to Tonawanda 

 Valley. With the change of outlet the discharge of the lake passed from the 

 Susquehanna drainage to the Mississippi. These lakes are called by Fairchild 



