Pleistocene of the Champlain Valley. — Baldwin. 177 
Winooski and other rivers, in its large sand delta and terraces 
extending far up the river, covering northern Schuyler and 
southern Plattsburgh, and in the gorge or rapids of its post- 
glacial channel. One definite level of this delta is at 445 feet. 
The highest terrace here is at 561 feet. The change from the 
high glaciated region to the lacustrine and marine area is 
very well marked by the disappearance of kanies and kettle- 
holes, and by prevailing shore levels and terraces, and in de- 
scending to the present lake at least ten distinct terraces 
may be seen. 
The blue clay appears under the township of Plattsburgh 
bearing marine shells, in a bed five inches thick, at its junc- 
tion with the sands above, and they may be found almost 
anywhere at 190 feet. We found these shells again at a level 
which Dr. I). S. Kellogg, of Plattsburgh. informs me is 346 
feet. Dr. Kellogg pointed out two interesting examples of 
buried eskers. One of these he has carefully mapped. It is 
seven miles long, extending from the south part of ('hazy into 
Beekmantown, and rises through the clays to about 60 to 80 
feet above them. The other one is near Morrisonville, on the 
Saranac, where the road cuts a fine section through a consid- 
erable deposit of drift, which has been completely covered by 
the sand of the high level of the delta. This exhibits the same 
conditions as the esker described from West Milton, hut more 
clearly. From Chazy the Champlain valley soon opens into 
the broad clay plain of the St. Lawrence. 
Outlet to the North. An examination of the map (Plate V) 
will show that lake Champlain is largely over 200 feet dee}), 
and in one place it reaches a depth of 400 1'eet, although the 
present mean surface of the lake is onl}* 1)7 feet above mean 
sea level. While the uplifting of the mountains of Vermont 
and New York probably had much to do with the .existence of a 
valley here, yet the valley itself is certainly a valley of erosion. 
Such a depth of channel below the sea level indicates a pre- 
glacial elevation for this region of more than 300 feet. Hut 
the elevation was probably very much more than that; tor the 
depth of deposition during and since the Glacial period, and 
the fall necessary in order to drain this valley to the sea, must 
be added. This corresponds well with the depths of the larger 
Laurentian lakes, and of the submerged channels of the St. 
Lawrence, the Hudson, and other rivers. 
