of the Eastern States. 229 



ous for considerable distances, as near New Brunswick, also 

 stands opposed to such a theory. The deposition of thin even 

 layers of sediment, on surfaces inclined at an angle of from 

 10 to 40 degrees, has never been recorded as occurring at the 

 present day. This theory, moreover, that these beds were de- 

 posited in an inclined position by a flowing river, does not al- 

 low for the formation of sun-cracks, rain-marks, foot-prints, 

 etc., which occur so abundantly in these rocks. Again, the 

 foot-prints which we have found at a number of localities in 

 New Jersey, show no indications of having been impressed on 

 a sloping surface. 



We cannot avoid the conclusion that the sandstones and 

 shales of this formation were spread out as nearly horizontal 

 sheets of sand and mud, although their wedge-shaped bedding 

 indicates that they must have been subjected to strong cur- 

 rents. As they are now inclined to the horizon at an angle of 

 about 10 to 15 degrees toward the northwest, the only reason- 

 able conclusion seems to be that they have been uplifted and 

 tilted into their present position. 



The trap-sheets in this formation, of which we will speak 

 more fully further on, are beds of hard crystalline rock, usual- 

 ly conformable with the associated sandstones and shales. 

 Owing to the denudation of these softer sedimentary beds, the 

 more compact trap has been left as a series of hills, which have 

 a gentle slope to the westward, corresponding to the dip of 

 the sandstones and shales, and present steep mural escarpments 

 to the eastward. In the valley of the Connecticut, we find 

 this order reversed. The association there is the same as in 

 New Jersey, viz, sandstones and shales bearing sun-cracks, 

 rain-drop impressions, foot-prints, etc., and also traversed by 

 sheets of trap. The whole system, however, is inclined to 

 the eastward at an angle of from 5 up to 50 degrees.* The 

 trap sheets in this valley, which usually conform in dip to the 

 associated sedimentary beds, have their steep escarpments fac- 

 ing the west, and slope gently to the eastward. 



* Hitchcock's Ichnology of Mass., p. 10. 



