78 NEW YORK STATE MUSEUM 



the rock. The stream detritus was dropped immediately northward 

 in the Dansville water, to be largely picked up in later stages of 

 the lowering waters and transported farther north. 



The numerous lower terraces in the valley from Portageville up as 

 far as Caneadea, and ranging from 1270 down to 1160, belong to the 

 morainal lake. 



Stage 7. Mount Morris-Geneseo lake. Outlets were by a series 

 of channels on the meridian of Batavia and lying between Linden 

 and East Bethany. The flow was west, across the Oatka and 

 Tonawanda valleys to the great glacial lake Warren, with ultimate 

 escape by Chicago to the Mississippi. The elevation of the outlet 

 channels declines from 1200 to- 1000 feet. 



The former stages were comparatively steady levels of the waters, 

 with only slow lowering as a permanent outlet was downcut. But 

 this stage, and subsequent stages, comprise a series of falling water- 

 levels as the receding ice front opened lower and lower passes on the 

 north-facing slopes. 



The several terraces north of the lower falls, with elevations of 

 1 180, 1 140 and 1090, may be correlated with these seventh stage 

 waters. They represent remnants of the deltas built in the Mount 

 Morris-Geneso lake by the river while it was cutting the Portage 

 canyon. 



Stage 8. Lake Hall. Outlets were between East Bethany and 

 Batavia with elevations from 1000 down to 900 feet, the waters 

 escaping to Lake Warren the same as in stage 7. 



So far as direction of escape is concerned this stage is only a 

 continuation of the stage 7, the outlet channels forming a con- 

 tinuous series \^sec N. Y. State Mus. Bui. 106, pi. 6]. It is made a 

 separate stage because the Genesee glacial waters are now blended 

 with the glacial waters of central New York. This stage is the 

 successor in the central part of the State to the glacial lake New- 

 berry, which had its outlet south by Horseheads and Elmira to the 

 Susquehanna. This body of water is named after James Hall. 



The water-leveled areas which correlate with this stage are the 

 terraces east of Bishop Corners, at 940, 900 and 860 feet; and the 

 extensive delta plain at Nunda, declining from 940 to 860 feet. 

 Also the broad summit plateau at 900 feet at the top of the Mount 

 Morris canyon, the " High Banks.'' 



Stage 9. Lake Vanuxem. Outlets were at Syracuse to the 

 Mohawk-Hudson, at elevation of 900 feet and declining. 



