436 H. L. FAIRCHILD — GLACIAL GENESEE LAKES. 



Five miles east of Wellsville, on Dykes creek, a small delta at the 

 mouth of an east-side creek was determined by close estimate at 1,610. 



The upper terraces seen further down the river at Scio, Belmont and 

 Belvidere are evidently of the Stone Dam plane, but they have not been 

 measured. The valley here is lower in altitude and the strongest levels 

 were produced by the waters of the next stage. In the valley of Van 

 Campens creek, around Friendship village, there are conspicuous pla- 

 teaus, roughly estimated at about 1,625 to 1,645 feet. These, however, 

 are not the summit levels, as this valley was the basin of an independent 

 local glacial lake (see page 447), and are consequentl}^ not conclusive. 



It should be noted that in general the terraces become lower as we go 

 northward. Theoretically, this is to be expected, as northwardly the ter- 

 races are successively later in time and the outlet was constantl}^ lowering. 



This lake, named the " Wellsville " lake, after the chief village within 

 its limits, existed for a long period and its work of shore erosion and 

 planation is very evident. It came to an end through the capture of its 

 waters b}^ a lower outlet than the Stone Dam channel. The lower outlet 

 was opened when the ice-dam uncovered the point of high ground in the 

 town of Belfiist on the western side of the valley, between the river and 

 Black creek. 



FOURTH STAGE: BELFAST-FILLMORE LAKE. 



Outlet. — The old outlet by Cuba is another fine exami)le of an aban- 

 doned river channel, but of a very different type from the Stone Dam 

 channel. The latter was a narrow rock-gorge. The Cuba channel is in 

 a broad, open, north-and-south valley. The divide north of Cuba is a 

 smooth plain, al)out one-half mile wide and continuous with the valley 

 bottom northward. Its present altitude is 1,496 feet. The old Genesee 

 valley canal traversed this pass, as does the successor of the canal, the 

 Western New York and Pennsylvania railroad. Foi- a stretch of several 

 miles, from Black Creek station to below Cuba, the railroad retains the 

 l,41)6-foot level. The Erie railroad enters this channel from the eastward 

 at Cuba village ui)on a terrace, which is ap[)arcntly an old Hood-plain, 40 

 feet above the i)resent channel. Further south the walls of the valley 

 seem to be rock, al)out one-third mile apart. All the way to Olean the 

 valley retains a fairly uniform width of about one-third to one-half mile. 

 Fragments of high, bordering plains and deltas at mouths of side streams 

 are seen at a height of 20 to oO feet above the ])resent floor of the valley. 

 The fall from Cuba to Olean is only 64 feet in 14 miles. Northward from 

 Black Creek station to Rockville the fall is 75 feet in four miles, and to 

 Belfast, three miles farther, 109 feet additional. 



The col may have been partially filled with drift. Tlio amount of 



