88 BUREAU OF AMERICAN ETHNOLOGY [bull. 60 



the present bottoms, after the common habit of existing degrading rivers. This 

 habit is recognized and the facts are summarized in the following quotation 

 (p. 73) : " At Little Falls, Minn., the eastern portion of the sandy plain on the 

 east side of the Mississippi is several feet lower than the crest of the plain at 

 the east end of the dam. That fact is important. After the great glacial river 

 which overspread the entire plain at Little Falls had withdrawn into the nar- 

 rower limits of an eroded stream bed, that river, often in freshet from the ef- 

 fects of the melting ice sheet, occasionally reoverflowed the entire plain, dis- 

 turbing and overturning the sandy surface, mixing into its materials every 

 chipped quartz blade or spall which had been placed by the hand of man upon 

 the surface adjoining the newly eroded and narrower channel. The higher 

 altitudes of the plain along the Mississippi between The Notch and the dam 

 were caused by successive stages of recurring overtlowage, creating additional 

 surface deposits upon the plain nearest to the newly formed river bank." This 

 is indeed " important," as the author himself naively remarks, since it shows, as 

 the author also recognizes with equal unconsciousness of its real meaning, that 

 it is the characteristic action of streams of the present nonglacial regime. 

 It is here recognized, with undoubted correctness, that the quartzes were buried 

 " by disturbing and overturning the sandy surface " and by " additional sur- 

 face deposits." The reference of this, however, to glacial waters is wholly 

 without evidence and quite against the probabilities. Glacial streams as a rule 

 have the aggrading haliit, and are not therefore " withdrawn into the narrower 

 limits of an eroiled stream bed," but on the contrary, are constantly shifting 

 their courses from one point to another across their whole plain. Usually they 

 subdivide into a complex plexus of numerous shallow shifting branches. There 

 is, therefore, no reason whatever to suppose that the present channel of the 

 Mississippi at Little Falls was in existence, even in its initial stages, while 

 the river remained truly a glacial stream. The fact that the relic-bearing de- 

 posit is closely related to the present stream is evidence that it ioas postglacial. 

 The deposit that carries the relics supports the same view, for it bears the char- 

 acteristics of a postglacial rather than a glacial formation. On the evidence 

 submitted, therefore, in the paper the inference is rather imperative that the 

 quartz chips were buried at some stage when postglacial rather than glacial 

 conditions prevailed. . . . 



Now, it seems clear from the evidence presented in the paper that the 

 quartz chips were not spread over the plain while the clean stratified gravels 

 were being formed, nor while the river was meandering over the plain in its 

 transitional adjustment stage, nor in its general degradational stage, for at 

 all of these stages, scour-and-fill should have incorporated the chips in the 

 stratified sands and gravels. The chips were quite clearly introduced after the 

 Mississippi had " withdrawn into the narrower limits of an eroded stream 

 bed " and while only its flood stages overflowed the upper plain. ... As the 

 recent cutting down of the channel has been slow on account of the slate 

 barrier, a very considerable period has probably elapsed since the INIississippi 

 last reached the upper plain even in its highest flood stages, except as these 

 might be made exceptional by ice jams and similar obstructions. This gives 

 the origin of the chips a respectable antiquity, but does not offer any pre- 

 sumption that it fell within the glacial period, or even very near its close.* 



Considering this masterly analysis of the phenomena of post- 

 glacial river action, as applied to the Little Falls site, no other view 



^ Chamberlin, Review of " Kakabikansing," by J. V. Brower, pp. 794-798. 



