542 J. E. TODD — PLEISTOCENE PROBLEMS IN MISSOURI. 



of Kansas City and the Missouri river, from that point nearly to Jeffer- 

 son City, and down the Cuivre valley as far as Troy and along the Mis- 

 sissippi, perhaps crossing it as far south as Hannibal. This, as I under- 

 stand it, has been the conception entertained by previous writers upon 

 the Quaternary deposits of Missouri. From the light brought out by 

 the study, the principal conclusions of which have been already 'given, 

 several difficult questions arise. 



Objections to the Hypothesis. — In considering this hypothesis one of the 

 most serious difficulties is the disagreement of the foregoing supposition 

 with the great difference in altitude of the drift in Missouri and that in 

 Illinois, not fifty miles away, together with the absence of drift over 

 Saint Louis county and down the valley of the Meramec. Since we find 

 no gravel or other evidences of rapid streams descending from the edge 

 of the drift down to the present river, we would naturally suppose that 

 the waters of that mighty flood flowed gently near the altitude of the 

 Missouri drift or, in other words, at an altitude of about 800 to 900 feet 

 above the sea in the vicinity of the col connecting the valley of the 

 Missouri with that of the Meramec ; but the altitude of that col is less 

 than 700 feet, and no traces of northern drift transported by water are 

 found either upon it or down the valley of the latter stream. Moreover, no 

 traces of northern erratics are found over the area north of this valley, as 

 we should naturally expect if this stream ever flowed at that altitude, nor 

 in the valley of the former stream more than 150 feet above its present 

 level. If we suppose that this region was once sprinkled with northern 

 erratics, it seems impossible that they should have been entirely removed 

 by erosion. If, on the other hand, we suppose that the waters draining 

 from the land-ice flowed in the Missouri at too low a level to escape 

 over Grays summit into the Meramec, or to cover the high land between 

 Saint Charles and Saint Louis, then how can we avoid the conclusion 

 that torrential streams must have plunged violently down the short 

 steeps from the level of the ice to that of the Missouri 200 or 300 feet 

 below ; and, if so, why should we not find numerous bowlders and frag- 

 ments of torrential deposits of sand and gravel, hid away in some nooks 

 of the old ravines ? The whole margin of the supposed land-ice in Mis- 

 souri must have presented phenomena of such character more or less. 

 How impossible that all should have been swept away ! 



Moreover, if some solution of this difficulty could be found, so far as 

 it concerns the bowldery drift, how could we conceive the deposition of 

 the higher loess and gray loamy clay to have occurred with this yawn- 

 ing gorge all around ? * 



*Surely Darwin's suggestion, recently reiterated by Geikie, that valleys became choked with 

 snow or ice, can scarcely be conceived adequate to explain this case. (Fragments of Earth-Lore, 

 page 180 ; teste, Am. Jour. Sci., vol. 47, p. 150.) 



