101 



of it, and in part from the three inferior older secondary forma- 

 tions of its own group, ranging parallel wiih it in the Kittatinny 

 Valley. Among these materials we occasionally meet rounded 

 pebbles of the flint or chert, characteristic of the limestone, though 

 none of the softer carbonate of lime itself; also small flattish frag- 

 ments of the directly underlying slate rocks. 



These constituents, of themselves, imply that some great dis- 

 turbance of the shores of the Appalachian sea must have taken 

 place suddenly, interrupting the deposition of the slate, and giving 

 rise to a series of new and more violent currents, sweeping into 

 it a coarser class of materials from the neighbouring land and 

 from the freshly risen sediments which now form the Kittatinny 

 Valley. But on this interesting point we are not left to inferences 

 derived merely from the nature of the rock ; for towards its north- 

 eastern termination, we find this formation, as we approach the 

 Hudson, resting unconformably, with a gentle dip to the north- 

 west, upon the upturned and contorted beds of the slate, giving 

 unequivocal proof of the violence of the subterranean actions 

 which attended the commencement of this extensive sandstone 

 deposit. Whether the lower formations of the Kittatinny Valley 

 emerged entirely above the waves at this epoch, in the tract which 

 they now occupy in New Jersey, is a point open to doubt, though 

 there exists strong evidence for believing, that, over some portions 

 of their range at least, further to the northeast, in the neighbour- 

 hood of the Hudson and beyond it, they were thus uplifted. The 

 general augmentation in the coarseness of the materials of the 

 sandstone formation, as we advance from the Susquehanna towards 

 the Hudson, would tend to confirm the opinion, that in this latter 

 quarter the disturbances which ushered in this fourth epoch of 

 the ancient secondary period had their greatest energy. 



The gray sandstone of the Kittatinny Mountain is the only 

 rock of the whole lower secondary group within the State, 

 from the limestone of the eastern side of the valley to the lime- 

 stone of the olive slate formation skirting the Delaware in Sussex 

 county, which exhibits none of the oblique cleavage planes so 

 conspicuous in Formation III. Its massive beds are traversed by 

 joints, having the same dip and strike, and attributable, probably, 

 to the same origin. 



Its quartzose materials and coarse aggregation have probably 



9* 



