276 GEOLOGY. 



Republican, in Township 27 West, 1 and 2 North. It is exposed 

 for many lmles: 



1 . Loess 4 feet. 



2. Black soil 2 " 



3. Loess extending down to upper terrace 4 " 



4. Black soil 1^" 



5. Loess 5 " 



6. Black soil 1)£" 



7. Stratified loess 15 " 



Another section, taken two miles above the Republican Forks in 

 Dundy County, from the sides of a small tributary, showed the 

 following" characters: 



1 . Black soil 1 foot. 



2 . Loess 5 feet. 



3. Black soil 1 foot. 



4. Loess 15 feet. 



The following section was taken near the Arickeree, about six 

 miles east of the west line of the State. This section can be dupli- 

 cated in any of the numerous small canyons in this region : 



1. Black soil 1% feet. 



2. Loess 15 " 



3. Black soil 2 " 



4. Loess as far as exposed 15 " 



Now, in all these sections the Loess next to the Black soils from 

 below is specially full of root marks — the Loess at the bottom of 

 the sections as well as at the top. This indicates that during the 

 progress of the Loess period there were many changes of level,, 

 during some of which these regions became level surfaces, similar 

 to the present, and covered with a rich black soil. These old land 

 surfaces became covered with grasses, whose roots penetrated far 

 into the underlying Loess. Changes of level, and lake conditions 

 came on again, and deposited more Loess, and these changes, con- 

 tinuino- through interminable centuries, have gone on till the present. 

 To show that the Republican region was not exceptionable in this 

 respect, the following section is given, from the canyon region 

 south of Plum Creek, on the road to Arrapahoe. It is near the 

 divide between the Platte and Republican: 



1. Black soil 3 feet. 



2. Loess 40 " 



3. Black soil 2 " 



4. Loess 15 " 



5. Clay with calcareous concretions 4 " 



G. Reddish sandy deposit, with a few calcareous concretions, only 



two feet exposed 2 < *■ 



