NEW YORK STATE ^lUSEUM 



GLACIAL DRALNAGE 



The present streams which enter this section of the Hudson val'ey 

 are the mtich diminished successors of the swollen glacial rivers which 

 swept an enormous amount of detritus into the valley. In the 

 northern part of the area the cliief inflow from the east is the Batten 

 kill, and on the west the tipper Hudson. During later glacial time, 

 while the ice margin lay against Luzerne and Palmertown mountains, 

 west of Glens Falls, the tipper Hudson flow was forced south, at 

 Corinth, through the vaUey of present Kayaderosseras creek, 

 noted by Wright in 1895 (2. page 674). The great sand plain north 

 of Ballston Spa was built as the delta of the glacial Hudson in the 

 waters at marine level, v.^hich now has a summit altitude here of 

 380 feet. The plain is now at 400 feet. When the ice lobe receded 

 from, the face of Palmertown mountain the Hudson foufid its present 

 course through the narrow defile cutting the Luzerne mountains. 

 The first flow must have been only just below its previous channel 

 at South Corinth, which is now 640 feet. The east face of Palmer- 

 town mountain must have been swept by the river from 640 feet 

 down to the sea-level waters, at 440 feet. Fine bars at 440 feet lie 

 close to the east face of the mountain, clearly attesting later wave 

 work. As pointed out by Woodwprth, the early Hudson flow past 

 Palmertown mountain produced the sand plains southward at Forts- 

 ville and toward Gansevoort (4. pages 144-49). -Ice blocks buried 

 in the glacial and delta gravels west of Fortsville have produced 

 the numerous kettles and lake basins. 



As the ice margin backed away, northward, the river poured its 

 burden of detritus freely over the plain and built the extensive sand 

 plains eastward toward Fort Edward and northeastward toward 

 Glens Falls. The strong terracing with bold fronts exhibits the 

 effects of the slow rise of the district out of the marine-level waters. 



In the central 'part of the map area the Kayaderosseras creek 

 became the successor of the early Hudson river and must have con- 

 tributed to the building of the lower sand plains on the west side of 

 the broad valley in the neighborhood of Bal'.ston Spa. 



In the southern part of the area the Hoosic river was always the 

 large contributor from the east. But the great flood poured in 

 from^ the west. The largest of all the glacial rivers that entered 

 the Hudson valley was the predecessor of the present Mohawk, 

 named the Glaciomohawk and the Iromohawk (10, page 38). For 

 a very long time, probably many thousand years the latter river 



