HOLMES] ABORIGINAL AMERICAN" ANTIQUITIES PART I 87 



As indicated by the various observations, the association of the 

 quartzes with the flood-phiin deposits is that of irregular scattering 

 such as would result from carrying and dropping by successive sand- 

 and gravel-carrying floods or by freshet-borne ice. 



The period or periods represented are necessarily subsequent to 

 the occupation of the river banks at the points of the quartz-bearing 

 outcrop as quarry and shop sites. This time is likely to have been 

 very long subsequent to the retreat of the ice from the immediate 

 locality. It is hardly reasonable to suppose that it was during the 

 immediate presence of the ice. The discriminations of Professor 

 Chamberlin on this point in reviewing the work of Mr. Brower are 

 -worthy of the closest consideration by students of the subject. They 

 are in part as follows: 



The descriptions of Mv. Brower are apparently careful and candid, so far as 

 intention goes, but tliey are obviously not those of a critical geological observer. 

 They neglect most of the really discriminative factors and embrace much in- 

 consequential matter. Notably also they have the trait, so common to the 

 untrained worker, of incorporating interpretation unconsciously while insist- 

 ing on " ascertained facts." " Tlie glacial river " plays a notable part in 

 the description of the formations, whereas the very thing to be demonstrated 

 is the " glacial " or nonglacial character of the river at the time the formations 

 in question were made. . . . 



It appears that there overspreads the plain once occupied by the Mississippi 

 waters, but now above their reach, a surface layer of dirty pebbly sand of the 

 typical structureless kind which usually covers abandoned flood plains of sand 

 and gravel. This is about four feet thick and at places near the river con- 

 tains many chips of white vein quartz of imdoubted human origin. The source 

 of the quartz is unquestionably the veins in the outcropping slate over which 

 the falls are formed. This quartz-bearing slate does not now rise as high as 

 the upper surface of the plain, and this fact has been urged by Holmes and 

 Hershey as evidence that the quartz chippings wei'e not taken from the parent 

 ledge until the plain had been cut down to the requisite depth after its original 

 completion. Mr. Brower, while not answering this objection by positive evi- 

 dence, holds that the crest of the quartz-bearing ledge was exiiosed at seasons 

 of low water, though covered at times of flood. It is of course probable that the 

 crest of the ledge has been worn down where the river flows over it, but such 

 erosive covering by the river does not fit in well with the view that this same 

 portion was the source whence large quantities of vein quartz were quarried 

 at the same time. It is clearly urging a bare possibility at best rather than a 

 probable occurrence. 



If, however, the case rested merely on the possibility of reaching the source 

 of the quartz while yet the uppermost layers of the original plain were in the 

 process of formation, it might be ungenerous to refuse to entertain the utmost 

 possibilities of the case in favor of glacial man in America. But the facts of 

 the case, taken .I'nst as given in this paper, do not seem to the reviewer to af- 

 ford even a plausible ground for assigning the quartz chips to the glacial stage 

 of the river. The surface deposit in which they are found, as described and 

 illustrated in the paper, not only does not bear the characteristics of a glacio- 

 fluvial deposit, but bears quite clear evidence that it is not glacio-fluvial. The 

 descriptions cite the fact that the surface deposit is highest near the bank of 



