GEOLOGICAL SURVEY OF THE TERRITOEIES. 29 



in the soil, derived from the erosion of the Cretaceous sandstones, would 

 render these broad level prairies admirable for wheat. Although the 

 grass is so abundant and nutritious, I fear the lack of living water will 

 prevent certain i)ortions of this region from being useful for stock-rais- 

 ing. It seems to me too flat and wet at certain seasons for sheep to 

 prosper well. There is an interval of about eighteen miles between Big 

 and Little Blue Elvers along this road without a dwelling. On Eock 

 Creek the settlements begin to grow numerous again, and nearly all the 

 bottom-land of the Little Blue is taken up by the actual settlers. There 

 are some excellent farms here, and the crops the present season are 

 very bountiful. 



On Eock Creek, a little branch six or seven miles long, we saw the 

 first exposure of rock — the red sandstones of the Dakota group. Along 

 the Blue for eight or ten miles quite precipitous ravines are formed by 

 this rock, as shown by the illustration. 



Fig. 1 shows a bluff or projecting ledge of sandstones along the Little 

 Blue, and Fig. 2 represents one of the many rugged ravines near the 

 mouth of Eock and Eose Creeks. The clays, sand, and sandstones of 

 the Dakota group extend down the Little Blue to a point about two 

 miles below the south line of Nebraska, and, of course, influence the 

 agricultural character of the entire region. 



The soils of a district are generally composed, to a greater or less ex- 

 tent, of the eroded materials of the underlying basis rocks. The sand- 

 stones of this formation being largely composed of silica, the soils and 

 subsoils are largely formed of silica also ; and the consequence is that 

 wheat and oats grow remarkably well, but corn-crops are not as good. 



The wheat raised in the district underlaid by the sandstones of the 

 Dakota group is said to weigh more per measured bushel than that from 

 any other portion of the State. 



These districts also produce most excellent nutritious grass, and the 

 hills, though covered with a thin soil, would be superior for sheep-graz- 

 ing. Indeed, as we go west of this latitude, the uplands are more suit- 

 able for stock-raising. The water, though somewhat scarce, is most ex- 

 cellent, and the climate healthy. A section of the rocks along the Lit- 

 tle Blue, below the Big Sandy, would be as follows, descending : 



5. Yellow and dark-brown rust-colored sandstones of the Cretaceous 

 or Dakota group, so well known in many other portions of the West. A 

 few dicotyledonous leaves were found. This bed is of irregular thick- 

 ness, from 50 to 100 feet. 



4. Moderately coarse, yellowish- white sand, with irregular laminae of 

 deposition — 50 feet. 



3. Dark-colored, arenaceous, laminated clays, with particles and seams 

 of carbonaceous matter. All through are beds of carbonaceous clay, 18 

 inches to 3 feet thick — much sulphuret of iron and silicified wood — 30 to 

 50 feet. 



2. Variegated arenaceous clays ; the slopes exposed are so great that 

 I cannot give the exact thickness — probably 50 to 70 feet. Some seams 

 of excellent potters' clay. 



1. Dark-bluish shaly clay, upon which the foundation of Mr. Jen- 

 kins's mill rests. .It is, undoubtedly, Permian or Permo-Carboniferous, 

 but is not exposed to view by natural excavations until we reach a point 

 south of the Nebraska line near Marysville, Kansas. 



The dark bed in division 3 of the above section has been regarded by 

 the settlers with a good deal of interest as indicating the proximity of 

 a workable bed of coal. I gave all the exposures a careful examination 

 and found them of no possible value. 



