Geological Pa^yers. 85 



27, range 8, near the head of Spring creek, the coquina layer has 

 become a calcareous shale, very yellow, with about six inches of 

 Cottonwood limestone above it. Very few Fiisulhm are seen in it. 



Coming around the divide between Spring and Otter creeks, the 

 outcrop becomes miore like the normal Cottonwood lime It erodes; 

 smoothly and has the texture of the Cottonwood lime; when the 

 honeycombed layer is examined the fracture reveals the fact that 

 the moUuscan layer has become crystalline. The appearance of 

 the stratum here is that it is repeatedly changing to normal Cot- 

 tonwood lime. A large part of the stratum here would serve for 

 building purposes. The fauna of the Florena shales is well seen at 

 this point; also the calcareous shale below the Cottonwood lime. 

 The layer at the top of the Florena shale has changed decidedly in 

 appearance. It now has the fracture and texture of the Cotton- 

 wood lime in hardness and general lithological characters, and 

 forms as prominent an escarpment as the Cottonwood, its vertical 

 position being unchanged. Also, the Nevas at this place make 

 prominent escarpments. 



In the northwest quarter of section 2, township 28, range 8, the 

 Cottonwood lime is well shown in a cut on the Frisco railroad. 

 The limestone measures five feet eight inches in thickness: 



5. The upper part, two feet 4 inches in thickness, has the usual appear- 

 ance of the Cottonwood lime. Some Fusulina are seen in it and some cri- 

 noid stems. The color is tinged with red instead of yellow, but has the 

 texture of the Cottonwood lime. 



4. Below this is a soft, shaly layer of from one to two inches in thick- 

 ness. 



3. The layer of stone that I have described above as the violet mollus- 

 can shows clearly the shells of which it is composed, at the weathered sur- 

 face. It also has red specks of iron in it. Thickness, eight inches. 



2. A very thin lamina, less than one-fourth of an inch in thickness. 



1. The basal layer, two and one-half feet in thickness, is a more co«- 

 glomerate-looking stone, as though it was made up of much larger shells. 

 This is the part that causes the rough, rugged boulders to the north. The 

 limestone at the top of the Florena shales is still somewhat prominent and 

 has a good deal of the appearance of Cottonwood lime, except that the 

 Fusulina are at the bottom. 



In the northeast quarter of section 11, township 28, range 8. the 

 Cottonwood limestone appears on two very small mounds — prob- 

 ably an acre in the west one, and still less in the one to the east — 

 the limestone being the top layer of each mound. The dip to the 

 southeast is a little lees than 2°. 



Quite a narrow syncline is noticed between the two ponds by the 

 railroad, a litle west of Derry, or Blodgett. This synclinal fold 

 may be seen distinctly by beginning at the railroad cut, already 



