GLACIAL WATERS IN THE LAKE ERIE BASIN' 



27 



steep north bluff in till, 40 feet high. This channel would seem to 

 be the latest and lowest, on this meridian, of the glacial drainage. 

 It was the western extension of two glacial ehannels from the east. 

 The higher of these forms a cut bluff at the three-corners on the 

 Townline road, 2 miles northeast of East Aurora. Its westward 

 continuation is seen leading southwest, south of the Manila Street 

 road, nearly to the village where it meets the present drainage. 

 Another lower and broad channel crosses the Townline road a little 

 distance north of the former, and south of tin- next three-corners, 

 and leads west into the indefinite swampy tract a mile northeast 

 of the village and which forms the head of the capacious channel 

 north of the village. 



Between the two old channels above noted lies a delta gravel 

 plain which supports the Marilla Street road. This plain is much 

 pitted along its northern margin, showing that it was deposited 

 against the ice front; masses of the ice being buried in the gravel, 

 their subsequent melting produced the basins or "kettles" in the 

 plain. 



East and northeast of East Elma, and curving around from 

 north of Porterville to near Marilla, is another extensive and 

 interesting delta plain. The northern margin certainly lay against 

 the ice front, as is proven by the kettles or " pitted-plain" surface. 

 At least nine glacial streams from the east share the responsibility 

 for this deposit, the channels being distributed for 3 miles along 

 the north and south road between Porterville and Marilla. The 

 debouchure of the higher channels and their relation to the delta 

 show clearly from the highway. The varying altitude of this 

 multiple delta plain, 920 to 940, seems to correlate with the Whit- 

 tlesey waters, which in this region had their greatest eastward 

 extension with an altitude over 900 feet. This broad delta lies 

 above and cast of the hamlet of East Elma, and we will call it the 

 East Elma delta. 



The latest ice border drainage on this meridian has left two 

 channels east and northeast of Marilla. The earlier of the two 

 streams cut a conspicuous bluff back of the cemetery, southeast 

 of the village, and also a channel about a mile southwest of the vil- 

 lage, leading over to Buffalo creek at the Warren level. Marilla 

 lies on a delta. The upper terrace, about 860 feet, may have been 

 partially formed at the ice front in local waters connected with 

 the glacial streams just noted, but as a plain of the ancient kittle 

 Buffalo creek the gravel terrace continues il miles northwest 

 into the W T arren delta plain, capped with wave-built bars. The 



