776 T. C. CHAMBERLIN 



nicety quite improbable, and in the third place, the view leaves 

 very little erosion and deposition to be referred to the long, 

 subsequent stages, and in the fourth place, it leaves the adjust, 

 ment of the tributary to the Missouri a matter of accident, and 

 two accidents of nice adjustment in one hypothesis are some- 

 what too many. 



5) At the other extreme, it is perhaps possible to refer the 

 burial to very modern action of the Missouri waters at a very 

 exceptionally high stage, combined with deposition by the tribu- 

 tary, aided by slope wash and creep and wind work from the 

 Missouri bottoms. This seems to me, however, to be pressing 

 agencies to the limit of their possibilities rather than resting 

 with their probabilities within the limits of their more habitual 

 action. 



Without holding it to be quite demonstrable, it seems to me 

 that the weight of evidence is very strong in favor of the first 

 and most conservative interpretation, which finds an apt and 

 adequate explanation in the natural order of things. 



In this connection, I beg to invite the attention of archaeolo- 

 gists to the slight grounds for hope of finding really strong evi- 

 dences of man's antiquity in the fluvial deposits of the glacial 

 rivers, because of the liability of these deposits to deep over- 

 working by scour-and-fill. On the Ohio, for example, the floods 

 are today boring out deep holes in the river and shortly filling 

 these again, only to bore and fill somewhere else. It would 

 doubtless not be difficult to sow coins of this year's mint over 

 the bottom of this river in such a way that a decade hence they 

 would be buried a score or some scores of feet in gravel and 

 sand ; and what is more, this gravel and sand would be of the 

 glacio-fluvial type, since it would be only the true glacio-fluvial 

 material rearranged by stream action not unlike that which origi- 

 nally formed it. It would hence be stratified, and nearly or 

 quite indistinguishable in small sections from the original. The 

 same process has been in progress ever since the river began to 

 erode the glacial filling. If its early meanders covered the whole 

 of the original glacial flood plain, no part of it would be exempt 

 from the suspicion of such overworking and natural intrusion. 



