ELIZABETHTOWN GROUP 667 



morainal lake, but a glacial lake extending from a point 2y 2 miles south 

 of New Russia to Cross, 5 miles north of Lewis. This would make it 

 quite extensive. 



Black River water level (altitude, 510 feet). — On both sides of the 

 present fLoodplain of the Black Eiver, which lies to the east of Elizabeth - 

 town, terraces occur at 510 feet in altitude. They are definite enough 

 to have been made by glacial or marine waters, although there is the 

 possibility that they are remnants of river floodplains. The Black Wivcr 

 is today a typical overburdened stream. It has produced extensive flood- 

 plains below the terraces, which can be easily observed from the Elizabeth- 

 town -Westport highway. 



Summary of the glacial Lake Succession 

 keene valley group 



The ice-sheet first melted around the mountain peaks and gradually 

 retreated down the slopes, taking the form of irregular rings of ice that 

 held glacial waters. Continued melting exposed the upper ends of the 

 South Meadows and Keene valleys, in which the South Meadows and 

 Kcene lakes were formed, their drainage being west and south respectively. 

 The altitudes were maintained as long as the ice covered every other 

 possible outlet. At a later period a lower outlet was found when the ice 

 left the northern slopes of Ampersand Mountain, allowing the drainage 

 to pass to the west. Both the above-mentioned lakes were then united in 

 the Newman Lake, with the Wilmington Notch acting as the connecting- 

 link. 



The Saranac waters succeeded Lake Newman because of the opening 

 of lower outlet channels, probably in the Black Mountain Pass, with its 

 side channels successively opened up by the retreating ice-lobes, thus 

 lowering the Saranac level through many steps. 



The first series of definite beaches, deltas, and terraces was furnished 

 by Wilmington Lake in the eastern section of the region. The drainage 

 of this lake was westward through the Gulf over a series of cataracts, and 

 finally along the ice-lobes into the Hudson River Valley. The South 

 Meadows area was drained through this same outlet. 



Lake Wilmington was succeeded by a number of other glacial lakes, 

 because of the unusual topography, which, as the ice retreated, opened up 

 a succession of outlets at lower levels, the lowest of these levels being of 

 marine origin, dating from the time when the Hudson-Champlain Strait 

 connected the Champlain Sea with the Atlantic Ocean. 



