EVIDENCES(?) OF WATER-DEPOSITION OF LOESS. 377 



the Am. Geologist, 1. c, argue that the Missouri could have 

 discharged the amount of water necessary for these vast floods. 

 Their arguments only demonstrate that powerful currents 

 would be necessary to accomplish this. They underestimate, 

 however, the volume of water which would have been moved 

 during each great flood if the loess was deposited in this man- 

 ner. Manifestly every part of the area covered by loess would 

 have to be flooded. Professor Broadhead says that " it is very 

 rarely that the loess is found more than six miles from the 

 Missouri river. ..." This is not correct even for Missouri as 

 the writer knows from personal observation, and as Professor 

 Marbut reports,* but it is entirely wrong for Iowa, where the 

 loess extends from the Missouri to the Mississippi, passing 

 over the divide between the two drainage -systems ! There- 

 fore, these floods would have formed an enormous body of 

 water, and not only would more time have been required to 

 move them, but the necessary strong currents would not have 

 left fine material such as loess on the bluffs which border the 

 main streams, and which, therefore, would have been exposed 

 to these strong currents. Professor Wright argues that the 

 fact that loess -particles nearer the main stream are somewhat 

 coarser than those in outlying districts, supports his conten- 

 tion, but this difference is entirely too insignificant for his pur- 

 pose, for the particles of the coarsest loess are still very much 

 finer even than Miss Owen's building-sand (seep. 227, 1. c). 

 In their anxiety to prove that the Missouri could discharge 

 these floods and carry enough material to form the loess de- 

 posits, these authors have called into existence conditions 

 which would result in the distribution of material much 

 coarser than appears in the loess. Excepting where it is cov- 

 ered by the newer drifts the loess uniformly forms the surface 

 deposit. In no part of the vast loess - covered area is there 

 any deviation from this rule. If we exnnine the valley of 

 any larger stream after a flood, we find masses of sand and 

 gravel moved out over at least some of the higher ground 



See map opposite p. 80 in Williams' " The State of Missouri," 1904. 



