PLEISTOCENE MARINE SUBMERGENCE 39 



which was diverted southward by the persistent ice block. Yet 

 further land uplift diverted the river flow into its present channel. 



If the record is correctly interpreted we have a correlation with 

 Lake Iroquois history. The outflow of Iroquois continued here 

 until the Covey outlet was opened. This implies that 200 feet 

 of land uplift had taken place at Round lake when the ice front 

 reached Covey hill, leaving 180 feet of rise in later time. It also 

 gives an illustration of the persistence of buried ice blocks until 

 exposure to the air. For further discussion the reader is referred 

 to paper 93. 



On the irregular rocky surface of the east side of the valley the 

 summit shore features are weak ; but they are found in the upper 

 terraces of the Hoosick delta at Schaghticoke and Valley Falls, 

 with an altitude of 380 to 385 feet. On the Schenectady sheet the 

 summit levels are seen on the delta plains at East Glenville, at 

 about 380 feet; and in the Mourning Kill delta, south of Ballston 

 Spa, at 390 feet. 



Saratoga and Schuylerville quadrangles. The Hudson river lies 

 on the eastern half of the Schuylerville map but the western border 

 of the estuary is mostly on the Saratoga sheet. On the latter sheet 

 we see the great sand plain north of Ballston Spa, which was built 

 by the glacial Kayaderosseras when it carried the glacial flow of 

 the upper Hudson, the latter being forced south at Corinth (76). 

 The full height of the plain is 400 feet by the map, which indicates 

 that the rolling surface was a few feet over the static waters. 

 Weak beaches and clifTs are found northwest and west of Sara- 

 toga Springs with a height of 400 feet and downward. The 

 Cryptozoan ledge has been laid bare by wave action of the sea-level 

 waters. 



On the east edge of the Schuylerville sheet the summit plane of 

 the estuary is seen in the highest terraces of the Batten kill delta, 

 at Greenwich, 420 feet, and in clififs southwest of the village. A 

 splendid gravel bar lies 3 miles south of Durkeetown, at an alti- 

 tude of 425 to 430 feet, only some 10 feet beneath the theoretic 

 level. The bar mapped by Woodworth, 2 miles north (plate 12 

 of 82), is under 300 feet. Between these two bars are several 

 good shore features, ranging from 400 feet down. 



Many shore features are found on the hills nort?ieast of Sara- 

 toga lake, which hills stood as a group of islands in the estuary 

 waters. 



The Batten kill drains a large territory on the east and in Ver- 

 mont. It filled its upper valley with coarse detritus, at Cambridge, 



