52 NEW YORK STATE MUSEUM 



earlier Iroquois, that through the Covey pass. Woodworth seems 

 to have recognized this. This imphes that the ice front rested 

 against the Altona-Beekmantown highland after the ice had 

 deserted the notch south of Covey hill. It also requires a glacial 

 lake in the embayment west of Altona. There are evidences of 

 standing water between Altona and Alder Bend, and north of 

 Ellenburg Depot at 900 to 960 feet. We may refer to this water 

 as the Ellenburg lake. 



The later outflow of Iroquois produced the features in the Can- 

 non Corners district. 



Cannon Corners district. Here we find another remarkable dis- 

 play of Pleistocene features, fully matching that described in 

 Altona. It includes vast areas of stripped rock, numerous river 

 channels, enormous piling of cobble deltas over large tracts, and 

 splendid development of high-level bars. 



The areas of stripped rock have been named above. They are 

 essentially a single area; that is, they represent the work of the 

 same drainage, the Iroquois outflow, with falling levels as it washed 

 the retreating ice front. The rocks are Potsdam sandstone, usually 

 in irregular terraces, but sometimes steeply dipping. The inclined 

 beds are well shown at Mitchell Rebideau's place, 2 miles south- 

 east of Covey gulf. The stripped rocks may be conveniently seen 

 by taking either of three roads: the indefinite and branching rock 

 roads leading west from near the schoolhouse, three-fourths of a 

 mile south of Canno;i Corners; the road going west from Cannon 

 Corners ; and the road at the White School, a mile north of the 

 Corners, leading to the Rebideau farms. The limits of the bare 

 rocks are not perfectly defined on the map. The rocks are par- 

 tially covered with scrub, bushes and huckleberries, and the pre- 

 cise mapping is not worth present effort. At a rough estimate, 

 they extend some 6 miles north and south, and perhaps average a 

 mile and one-half in width, or 9 square miles in area. The surface 

 in general declines eastward, and the river flow which swept them 

 clean migrated down the slope, clinging to the ice margin as the 

 glacier slowly gave way. The lowest points of bare rock, and the 

 termination of river work, lie along the north and south road from 

 Cannon Corners to Shea's Ones. One exp ^ure of rock is seen on 

 the highway one-half mile north of th^ corners, and another 

 three- fourths of a mile south of the international boundary. 



As the rivers reached the sea-level waters near the north and 

 south line of the highway, it is along this road that we find the 



