GLACIAL AND POST-GLACIAL HISTORY 621 



walls. In these parts of the Hudson it is beheved that an embay- 

 ment in the ice-front existed in the deeper water over the lower parts 

 of the plain, and that the ice- edge is marked (i) by the series of gravel 

 plateaus with the characters above mentioned at their upper margin ; 

 (2) by the kames fronted by clay-plains without intervening gravel 

 plateaus; and (3) by the series of elongate depressions like those 

 between the plateaus of the series south of Saratoga Springs now 

 occupied in part by lakes, such as Round Lake and Saratoga Lake, 

 Lonely Lake, and perhaps also Ballston Lake.' 



Such a form of the ice-front is marked, it is believed, by the deposits 

 (i) at Croton and Croton Landing, and at Haverstraw and North 

 Haverstraw (Fig. 9, Nos. 22, 15, and 17); (2) at Newburg-New 

 Windsor, and Fishkill-Dutchess Junction (Fig. 9, Nos. 37, 38, and 

 42, 41). Other places where the ice halted are marked (i) by the 

 South Schodack gravel plateau (Fig. 13, No. 73, p. 436) and the line 

 of kames extending northwest of East Greenbush (Fig. 13, No. 74), 

 by kames near Teller Hill, and the line extending through North 

 Albany to Newtonville (Fig. 13, No. 65), (2) by the South Bethlehem 

 gravel plateau (Fig. 13, No. 62); (3) by kames near New Scotland 

 and Voorheesville (Fig. 13, Nos. 63 and 64); (4) by the Troy gravel 

 plateau and kames (Fig. 13, No. 76); (5) by the series of gravel 

 plateaus separated by elongate depressions, south of Saratoga Springs, 

 where several successive positions of the ice-edge are marked; (6) 

 by the succession of kames and gravel plateaus near Glens Falls, 

 where several positions of the ice-edge are marked (Fig. 13, No. 85, 

 and Fig. 18, west of No. 86, and Nos. 87 to 89, p. 454). This 

 includes the Glen Lake kame area north of Glens Falls. 



The depth of water into which the ice flowed and built up kame 

 areas and similar deposits appears in places to have been considerable, 

 as much as 60 to 80, or possibly 100 feet, if the evidence furnished 

 by the Teller Hill kames, southeast of Albany (elevation of top, 280 

 feet) and the adjacent South Schodack-East Greenbush gravel plateau 

 (elevation, 340-360 feet) be correctly interpreted. The 260-280- 

 foot Lonely Lake gravel plateau (Fig. 13, No. 83) was built in water 



I The writer does not mean to imply here that the plateaus between these depres- 

 sions were built only from successive positions marked by the depressions, for probably 

 the building was in process during the i"etreat from one depression to the next succeeding. 



