LOESS OF CROWLEY'S RIDGE, ARKANSAS 149 



The lower loess is whitish, often somewhal putty-like, finer. 

 and less inclined to scale off from vertical banks. It usually con- 

 tains some calcareous nodules, sometimes iron streaks and bands, 

 and often many fossils. It is sometimes yellowish, especially just 

 below the reddish loess, arid it then often shows whitish lines 

 evidently formed by rootlets. 



Sometimes short bands of broken shells appear in the white 

 loess, especially where the upper pari of the loess is very fossi- 

 liferous. Such a hand is illustrated on Plate \T>. figure '2. These 

 hands are usually a foot or more in length, and are evidently 

 formed in vertical cavities which have been formed by water 

 following crevices. Such cavities are often gradually tilled with 

 material from the upper part of the stratum, and if that pari is 

 fossiliferous shells are sometimes washed down and deposited in 

 a layer on the hottom of such a cavity. The subsequent filling of 

 the cavity completes the imbedding of the shell layer. Such a 

 cavity is shown at (d) on Plate YB. figure 1. and a shell band 

 (the one which is figured on the same plate, figure 2) is set off by 

 markers at (c). 



In most of the exposures which were examined there is a more 

 or les-; distinct brownish band just below the lower loess, and 

 where this is the case the lower limit of the loess is sharply de- 

 fined. Sometimes this dark band is wanting, and then it is not 

 always easy to determine the lower limit of the loess, especially if 

 the underlying layer is of the same color as the whitish loess, as 

 sometimes occurs. It is evident that Call regarded this layer 

 below the white loess as "typical" loess, one of the two forms of 

 loess which he recognized, though he observes that it is not fossi- 

 liferous. It is probable that Salisbury regarded this as a lower 

 loess 5 , and Chamberlin was also inclined to so regard it 6 , but 

 added that "it remains with us an open question whether this 

 belongs to the glacial series or not." 



Its texture, its grading into gravelly deposits, and its lack of 

 fossils clearly show that it is not loess. The presence of calcare- 

 ous nodules (on which Call placed some reliance) in both the 

 white loess and the underlying stratum proves nothing as to iden- 

 tity or close relationship, for such nodules are formed not only 

 in loess, but also in drift (especially when modified I, etc. There 



4 Ibid., p. 171. 

 •Ibid., p. XV. 

 c Bulietin of the Geological Society of America, Vol. I, 1S90, p. 176. 



