GEOLOGY AND GEOGRAPHY OF CLAY DEPOSITS 107 



Still another at Rosendale, on the land of R. Lefever : 



Loam and yellow clay 20 feet 



Sand 50 " 



Blue clay 30 " 



Gravel " 



100 " 



At Lefever Falls: 



Coarse sand 40 feet 



Quicksand = 60 " 



Blue clay 42 " 



Rock " 



Total thickness 142 " 



At Rosendale Plains : 



Sandy soil 10 feet 



Blue clay 10 " 



Quicksand 10 " 



Blue clay and quicksand alternating 150 " 



Total thickness 180 " 



"We now come to a narrow portion of the river from Staatsburg 

 to Il^ew Hamburg, where the terrace if present is of small extent 

 and presumably underlain by drift material. 



Where the river broadens out again at Roseton at the head of 

 ISTewburg bay, there is a thick bed of clay. It is nearly all blue 

 and underlies the remnant of a terrace 120 feet high, which has 

 escaped entire destruction owing to its position in a reentrant 

 angle of the upper Cambrian limestone ridge along the river at 

 this point. The overlying stratified sand and gravel is 10 to 15 

 feet thick. At Jova's upper yard the clay rests on the glaciated 

 Kmestone, over whose surface are scattered several bowlders of 

 the same rock. The clay at Rose's yard is 180 feet thick, while 

 that at Jova's has a total thickness of 240 feet. A boring of 135 

 feet made at Rose's yard at river level is of interest in connec- 

 tion with the depth of the preglacial channel of the Hudson. 



