498 



NEW YORK STATE MUSEUM 



At Levant, four miles east of Jamestown, Chautauqua county, 

 is an interesting bed of blue clay underlying an area of several 

 acres. It is probably of post-glacial age, and the section as 

 determined by an artesian well-boring is : 



Yellow sand 4 feet 



Quicksand 4 inches 



Yellow clay 5 feet 



Blue clay 70 " 



Ilardpan " 



Total thickness 79 4 



The owner of the clay bed states that leaves are often found 

 between the layers of the clay at a depth of 15 or 20 feet. 



At Breesport near Elmira is a bank of blue clay rising from 

 the valley to a height of 50 feet. It was evidently formed when 

 the valley was dammed up, and has subsequently been much 

 eroded so that all that now remains is a narrow terrace along the 

 side of the valley. A similar deposit is found at Newfield south 

 of Ithaca. A moraine crosses the valley a mile or two south of 

 it. Deposits of clay suitable for brick and tile occur extensively 

 in the lowlands bordering the Mohawk river from Rome to 

 Schenectady. The beds vary in thickness from six to 15 feet 

 and are mostly of a red, blue, or gray color. 



Among the most extensive and important clay formations 

 occurring in New York are those of the Hudson valley. Here 

 are deposits of two types. (1) Estuary deposits of fine stratified 

 sand, yellow and blue clay, and (2) cross- bedded delta deposits, 

 the materials of which are much coarser. The estuary deposits 

 indicate a period of depression, and deposition in quiet water. 

 The clay is chiefly blue, but where the overlying sand is wanting 

 or is of slight thickness, it is weathered to yellow, this weather- 

 ing often extending to a depth of 15 feet below the surface, 

 and to a still greater depth along the line of fissures. The 

 depth of oxidation is of course influenced by the nature of 

 the clay ; the upper portion weathering easily on account 

 of its more sandy nature and hence looser texture. 



