of the Eastern States. 251 



rich in mines of magnetic iron ore, which may have furnished 

 some portion of the coloring matter spread so uniformly 

 through the sandstones and shales. 



From the coating of oxide of iron which covers so great a 

 portion of the grains in the Triassic sandstones, it seems that 

 they were deposited rapidly, and not subjected to a long wash- 

 ing on the beach, which would have removed the coloring 

 matter, and left them light-colored like the ordinary beach- 

 sand at the present day. The angular character of the grains 

 of felspar which occur abundantly in the sandstones, points to 

 the same conclusion. 



A great extent of Triassic beds must be concealed beneath 

 the more recent formations — the Cretaceous and Tertiary — of 

 New Jersey, and also probably beneath the ocean. The land 

 which separated the Triassic estuary from the open ocean, and 

 yet admitted the free access of the tides, must have existed to 

 the eastward of the present coast. The marine deposits which 

 formed outside of this barrier in the Triassic period, are now 

 submerged. These views, although incapable of direct proof, 

 are strongly supported by the fact that the true border of the 

 continent, as shown by the U. S. Coast Survey, lies at least 80 

 . miles eastward of the present shore-line. 



The Theory of Separate Basins. 



In Le Conte's Elements of Geology, the inclination of the 

 Triassic beds in the Connecticut "Valley, is briefly accounted 

 for by supposing that they were deposited horizontally in a 

 basin of crystalline rocks, and that one side of this area was 

 upheaved and the higher portion of the sedimentary beds cut 

 away by denudation.* Such a supposition implies that each 

 area of Triassic beds, as existing at present, represents about 

 the extent of the basin in which it was deposited. We should 

 find, were this the case, that each area would show the records 

 of shallow water and mud-flat conditions along its sides, and of 

 deeper- water accumulations through its center. This, as we 



* Page 441, Fig. 695. 



