GLACIAL WATERS IN THE LAKE ERIE BASIN 21 



which has been traced upstream for 8 miles to the Canadaway valley- 

 south of Fredonia. The head of this river channel lies within ^ mile 

 of the Shumla reservoir and nearly 3 miles south of Fredonia. It 

 here forms a dry gorge, about 100 feet deep and 2 miles long, known 

 locally as Wheeler's gulf [pi. 8-10], and utilized for grade by a 

 detour of the Dunkirk, Allegany Valley & Pittsburg Railroad. 

 Beyond this gorge is an open section of about ^ mile in length below 

 which the channel forms another gorge ij miles long, ending a mile 

 south of Lamberton. For the remaining 4 miles to Portland the 

 channel lies just above and landward of the Whittlesey beach. 

 The head of the river channel is iioo feet in altitude and the de- 

 bouchure is 800 feet. 



Some traces of stream cutting earlier and higher than the 

 Wheeler's gulf channel have been noted southeast of Portland, and 

 such must occur along all the slope to the northeast, which is quite 

 destitute of morainal drift up to about 1000 feet. 



Above Wheeler's gulf higher scourways are seen, one of which is 

 tributary to the gorge. Below the gulf, on the Fredonia meridian, 

 all the slope from iioo feet down is swept bare to the rock, and a 

 series of rock shelves head at 1050, 1000, 960, 900 and 860 feet by 

 the map, declining westward. The higher ones converge and unite 

 with the Wheeler's gulf channel south of Lamberton, but the lower 

 ones debouched into Lake Whittlesey east of Lamberton and 

 helped to form the delta deposits south of the village. 



Fredonia to Forestville [pi. 2-3]. The stream cuttings which head 

 south of Fredonia carried waters which were ponded in the Canada- 

 way valley at levels corresponding to these outlets. We may call 

 these waters the Shumla lakes, after the hamlet in the valley. The 

 depth of the lake when Wheeler's gulf was the outlet was about 200 

 feet, and the breadth about i mile. The reader will appreciate the 

 fact that the lakes must have been fed by glacial drainage past the 

 ice front from the east, and the proofs of such action are abundant. 

 From below Shumla to below Laona, about 2 miles, the east, wall of 

 the valley holds a great volume of delta deposits banked against the 

 slope. The higher of these form conspicuous terraces, visible for 

 miles and plainly seen from the railroad. These have an elevation 

 under iioo feet, thus correlating with the lake level when this was 

 fixed by the Wheeler's gulf outlet. But the delta deposits extend 

 down the valley to Fredonia through all levels to 750 feet, the lowest 

 level of Lake Warren. 



The conspicuous delta terraces in the valley east of Laona were 

 built in the Shumla lake by the rivers from the northeast, the 



