DETAILS OF THE JURA 157 



butte near the foothills and on the west side of the creek. It gives but a 

 small part of the Jurassic series and that at the base. 



Jura. 



Feet. 



5. Sandstone, white, soinwhat lamellar, and filled with ripple marks, containing 



at its base a very impure calcareous layer with abundant fossils 20 



4. Marl or clay shale, gray in color, with no fossils 20 



3. Sandstone, white, soft, and somewhat lamellar at base 10 



Bed Beds. 



2. Sandstone, massive, deep red 80 



1. Red shaly sandstone changing into red shale and finally passing into red clay 



with gypsum 190 



The red sandstone (2) belongs undoubtedly to the Red Bed series, 

 which is in this part of the Hills very arenaceous, having many bands of 

 sandstone interstratified with the clay and frequently becoming in consider- 

 able bodies a massive, though soft sandstone. The change is often sudden 

 from a soft and plastic red clay to a soft and massive red sandstone. 



To the northeast of the last section, and within two or three miles, com- 

 plete exposures were obtained of all the strata of the Jura from base to 

 summit. The following is the section : 



Cretaceous (N~o. 1). 



Feet. 

 10. Sandstone, reddish and yellowish, massive ; showing at base a small stratum 



of gray shale 150 



9. Sandstone, not well exposed 50 



Jura. 



8. Red sandy clay or shaly sandstone, quite soft, with bands of more massive 



but soft sandstone 60 



7. Shales or marls, gray and sandy 30 



6. Sandstone, white, containing near its base a calcareous layer, with fossils 

 similar to those in 5 of last section (with which stratum this is equiva- 

 lent) 20 



5. Shales or marls, grayish or greenish 45 



Bed Beds. 



4. Sandstones, soft and massive ; upper 10 feet white and shaly, lower part 



red 45 



3. Red shales, changing to red clay 170 



2. Gypsum, white and massive 10 



1. Red clay, containing much gypsum, in thin ramifying seams; to valley of 



creek 100 



