404 



LOESS DEPOSITED BY THE MISSISSIPPI. [Ch. XIX. 



forms 



flat, table-land, extending 



miles from the Mississipp 



Fig. 36. 



Valley of the Mississippi. 



Louisiana. 



Missi. R. 



Vicksburg. 



o 





1. Modern alluvium of Mississippi. 2. Loam or Loess. 3. /. Eocene. 4. Cretaceous. 



ward from e to d. It also recurs, as I learnt from Mr. 

 Forshey, to the west of the valley of the Mississippi, in 



Louisiana, or at c, fig. 36. 



The only fossils of a truly fluviatile character which have 



emams 



platform 



fish discovered lately (March 19, 1866,) by Colonel Green. 

 They were found in the great 

 north of Yicksburg, and only four feet below the surface, at 

 the height of 200 feet above high-water mark. They are 

 considered by Dr. Leidy to belong to the living buifalo-fish 



^ _ _ — A -^ ft I _1 



Mississippi 



more 



lation than usual of mud on a part of the inundated plain 

 on which no organic remains were usually preserved except 

 land-shells and succinese. I consider the loess, from its homo- 

 geneous nature, the absence of stratification, and its terres- 

 trial and amphibious shells, to have been formed by a great 

 river which, like the Nile, inundated the wide plains bor- 



dering it on each side. 



o 



must 



since its accumulation there have been great cnanges in uu* 

 level of the basin of the Mississippi. How far the loess may 

 have been anterior to all the formations pierced through m 

 the well at New Orleans, or whether it may have been con- 

 temporaneous with some of them, is a point I cannot pretend 



Hudson 



But 



timony to oscillations of level at a very modern period. 



it is evident that the basin of the Great River has under- 

 deposited, 



gone important changes 



since the loess was 



all 



although the species of land-shells contained therein are 

 now living. As to the mammalia, of which some bones have 

 been found in the lowest part of the loess and in clay a 







v 



i' 



ttfO ot 



still 1* 



Be' 





lustra 



alrea 



fresh* 1 



- 







on the 



inaiiiro 

 of soil 



failiii- 



for- 



auk 



MM* 



* 



sink d< 



of the 

 w i 



5 





pa 



'•Uui 

 *1 







'1 1; 



( lriv 



1 







»Q 



