232 The Physical History of the Trias 



this coarse deposit with the underlying beds may be studied at 

 Pomp ton, at Boonton, and on the Delaware. The conglomer- 

 ate is composed of angular as well as worn and rounded peb- 

 bles and boulders, derived mainly from the crystalline rocks to 

 the westward, and in many cases of large size, frequently from 

 sixty to a hundred pounds in weight. The geographical dis- 

 tribution of this deposit is given with some minuteness in Prof. 

 Rogers's final report on the geology of New Jersey, to which 

 we must refer our readers for further detail. 



After describing the different localities where this conglom- 

 erate occurs, Prof, Rogers seeks to explain its origin by assum- 

 ing* " a violent agitation of the whole belt of country, and the 

 vertical rising of the bed of the red shale valley to a higher 

 level, which would necessarily set into motion the entire body 

 of its waters. These, rushing impetuously along the shattered 

 strata of the base of the hills confining the current to the 

 northwest, would quickly roll their fragments into that con- 

 fused mass of coarse heterogeneous pebbles which we see, and 

 strew them in the detached beds of conglomerate which they 

 now form." " The protrusion of the trap, the formation and 

 deposition of the conglomerate, and the elevation and final 

 drainage of the whole red sandstone basin," are considered in 

 this report as simultaneous events, and also that " the whole 

 time occupied by these stupendous changes must have been ex- 

 tremely brief, compared with the period which produced the 

 main mass of the materials of the basin." 



After visiting several exposures of this interesting conglom- 

 erate, and studying its geological relations, it seems to us 

 needless to call into ]:>lay any of the cataclysmal forces so fre- 

 quently appealed to in the early days of geological inquiry. 

 To us, the beds of conglomerate skirting the western border of 

 the Trias in New Jersey, have a history very similar to that 

 of many other coarse conglomerates, differing but little in their 

 mode of accumulation from the beds of pebbles and rounded 

 stones found along many coasts at the present day. 



*Rep. G«ol. of N. J., 1810, p. 171. 



