142 GLACIAL FORMATIONS OF ERIE AND OHIO BASINS. 



It was suggested by Carll ^ that currents under the ice may in tliis 

 instance have excavated to a considerable depth below the level of the main 

 outlet, but it seems hardly necessary to assume that so much excavation 

 had been made through this agency. It is Carll's opinion that the old 

 drainage was northward from Lottsville to the valley of Lake Chautauqua 

 thi'ough the abandoned valley just noted. 



Possibly a part of Big Brokenstraw Creek also discharged to the 

 Lake Chautauqua Valley and carried with it the headwater portion of 

 French Creek, there being lowland connection with Little Brokenstraw along 

 Coffee Creek and Swamp Run near the north line of Pennsylvania and also 

 from Clymer, N. Y., eastward into the headwaters of Brokenstraw, and the 

 abandoned valley refei'red to above. But it seems more probable that the 

 headwater portion of Big Brokenstraw Creek connected toward the north 

 or west with French Creek and found a northward discharge to the Lake 

 Erie Basin. The lowlands connecting Big Brokenstraw with French Creek 

 are broader and have a slightly lower altitude than those connecting it 

 with Little Brokenstraw Creek. At Corry a broad lowland deeply filled 

 with drift connects Big Brokenstraw with the head of South French Creek. 

 This lowland also connects toward the north through Hare Creek Valley 

 with the main French Creek just above the old divide crossed by that 

 creek in the southwest corner of New York. From the point where this 

 lowland connects with French Creek an old valley leads northward to North 

 French Creek at Findley Lake, and from North French Creek a lowland 

 heavily covered with drift extends northward past Grahamsville to the plain 

 bordering Lake Erie near Northeast, Pa. The filling of drift is so great 

 in these lowlands that at present it is not possible to determine whether 

 there was formerly a northward discharge from Corry through these old 

 valleys into the basin of Lake Erie. 



The portion of French Creek Basin in eastern Erie County, Pa., is 

 connected with old valleys leading northward from South French to North 

 French Creek and thence to the headwaters of small tributaries of Lake 

 Erie. The valley of the present creek shows a marked constriction just 

 south of the Erie-Crawford county line, being reduced to about one-fourth 

 the usual width of that portion of the valley. These features seem to favor 

 northward discharge rather than a connection toward the southwest with 



' Second Geol. Survey Pennsylvania, Kept. I^, pp. 234-235. 



