5G8 INTER-GLACIAL AMERICAN MAN, 



obviously originally derived from a wide area of diverse geological 

 characteristics ; and subsequently re-arranged and intermingled by 

 the action of water. Prof. Cook mentions, in the Geology of New 

 Jersey, that "in the azoic and paleozoic regions of the State, the 

 denudation has been very extensive ; but it is not so easy to 

 measure its amount, as it is not at all probable that the surface 

 wa.s smooth when the denudation, whose marks we now see, was 

 in progress. That it must have been very great we may safely infer 

 from the immense quantity of material which we can identify from 

 the gneiss, the Potsdam sandstone, the magnesian and fossiliferous 

 limestones, the Oneida conglomerate, and .the whole series of upper 

 Silurian rocks, which are now scattered all over the State quite to 

 Cape May." Elsewhere, speaking "of this wear and movement of 

 earth, gravel and boulders," the same writer remarks, " in some 

 localities, as along the highlands from Boonton to Pompton, every 

 notch in the mountain has a hill of drift opposite to it, on the open 

 plain to the south-east." Hence the miscellaneous character of the 

 transported material, including enormous boulders, and smaller frag- 

 ments of granitic, hypogene, sandstone and limestone rocks ; along 

 with water-worn pebbles of the same granular argillite as the "turtle- 

 back " celts and other characteristic stone implements of this Dela- 

 ware River drift gravel, but no flint. 



Of the artificial origin of the flint spear-head there can be no 

 doubt. But there is no satisfactory evidence to justify its being 

 classed as a true drift implement ; and if the several well marked 

 specimens of the same type so slightly alluded to in the subsequently 

 appended note, are also flint implements, it still remains to be seen 

 how far there is reason for regarding them as other than intrusive 

 examples of a class of Indian implements of very common occurrence 

 in more superficial deposits. For indeed, when Dr. Abbott is dis- 

 cussing the origin of specimens identical with the seemingly genuine 

 drift implements of the " turtle back " celt form, but obtained on the 

 surface of the talus at the foot of the bluff", he remarks : " In ■ the 

 talus which now covers much of this bluff", there is nothing but the 

 uniform mass of rounded and angular pebbles, and with them such 

 chipped implements as the specimens here figured." He accordingly 

 follows up this statement with the pertinent question : " As already 

 pointed out, why should this recently displaced material only yield 

 the rudest forms of chipped stone implements, when the surface is 



