PLEISTOCENE MARINE SUBMERGENCE 37 



on the same isobase as the gravel bar south of Hudson, lo miles 

 distant and on the opposite side of the Hudson, with the same 

 altitude. 



The other and similar delta is that of Hannacrois creek, on the 

 north part of the sheet. This has not been examined, but the map 

 gives the height of the plains as 300 to 320 feet. 



The west side of the Hudson on this sheet shows only the lower 

 terraces of the detrital deposits in the estuary. 



Kinderhook sheet. This displays the broad sand plains related 

 to the Kinderhook river and its tributaries. The plain at Stuyvesant 

 Falls is 200 to 220 feet, or some 70 feet inferior to the summit 

 level. At Kinderhook the plain is 260 feet and over, or about 

 35 feet low. At Valatie, Niverville and Kinderhook lake the roll- 

 ing flats are sandy and have the summit level, 300 feet. Flat, weak 

 bars, characteristic of sand areas, occur northwest of Valatie at 

 300 to 305 feet. Weak cliffs are seen on the slopes east of Kinder- 

 hook and south of Valatie at the same height. 



Westward toward the Hudson the detrital plains exhibit the ter- 

 racing produced in the soft deposits by the subsiding waters. This 

 feature is characteristic of the detritus-filled valley from here north- 

 ward to Glens Falls, and very conspicuous in many sections. 



Albany and Troy sheets. On the Albany map is seen the larger 

 part of the great delta built by the Iromohawk river. The southern 

 plains about Selkirk are 200 feet altitude, and the delta rises stead- 

 ily to 350 or 355 feet at Schenectady. The delta and its genesis 

 has been described by Stoller (87) and the writer (164), and fur- 

 ther description here seems unnecessary. 



North of Albany is a bold summit shore line. Along the Lou- 

 donville road a strong cliff extends for two and one-half miles in 

 north and south direction, and the terrace facing it has provided 

 a level stretch for a handsome boulevard. This is a favorite subur- 

 ban residence district and popular drive. The south end of the 

 beach is along the east side of a morainal tract, and the cliff curves 

 sharply west about the south end of the hill between the Loudon- 

 ville and the Shaker roads. In altitude the beach is about 340 feet. 



On the Troy sheet inferior terraced plains are conspicuous along 

 the Boston & Albany Railroad through Schodaok town. The 

 higher, rolling plains with irregular surface in the district of Scho- 

 dack Center were probably laid in glacial waters, as noted by Wood- 

 worth (82, plate 8). The altitude of these plains, with kettles and 

 rough surface, is 20 to 30 feet over the estuary level, 330 ta 340 



