212 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



portion of the drainage basin had a northward discharge to a valley draining 

 the lower course of Tonawanda Creek The deflections of tributaries of 

 Buffalo Creek in passing the Crittenden or Forest beach are notable, as 

 shown in the discussion of that beach on a subsequent page. 



EIGHTEENMILE CREEK. 



This tributary of Lake Erie enters the lake about 18 miles southwest 

 of Buffalo, and this fact is probably responsible for the name applied to 

 the creek. It is formed by the union of two streams which have their 

 headwaters in the elevated uplands of sotithern Erie County and which flow 

 northwestward through deep preglacial valleys into the plain bordering the 

 lake. Their junction is only about 5 miles from the mouth of the stream. 

 It is probable that the preglacial continuation of the East Fork was 

 northward from near Hamburg into Lake Erie, though the precise line of 

 continuation is not known. ' The West Fork probably entered the Lake Erie 

 Basin along a different line from the present course of the creek, for the 

 stream is now excavating a rock gorge near its mouth but little wider than 

 the stream bed. It is possible that the. East a^d West forks had a common 

 line of discharge farther north than the present mouth of the creek. There 

 is, however, a belt of thick drift immediately south of the mouth of the 

 present stream, as shown by wells in the vicinity of Derby, and this may 

 prove to have been the line of discharge for the West Branch. 



CATTARAUGUS CREEK. 



Cattaraugus Creek enters Lake Erie at the village of Irving, about 12 

 miles east of Dunkirk, N. Y. It drains a large area in Cattaraugus County, 

 N. Y., but has only small tributaries from Erie and Chautauqua counties, 

 while its headwaters drain a small portion of Wyoming County and the 

 extreme northwest corner of Allegany County. Its source, like that of 

 Tonawanda Creek, is in Wethersfield Township, Wyoming County, in the 

 midst of a great inteidobate morainic belt. It has a general westerly course 

 from source to mouth. The northern ti'ibutaries are very small, but the 

 southern tributaries reach, in several cases, a length of 12 to 15 miles, 

 while the length of South Fork is fully 25 miles. The present limits of 

 the drainage basin are largely determined by drift obstructions. 



In a paper prepared in 1894 by Chamberlin and the writer, evidence 

 was set forth that the lower coiu'se of Cattaraugus Creek constituted the 



