JURASSIC FOSSILS. K*);') 



Cfetaccous. I'.-.t. 



13. Sandstone, yellow, with red sfaiiis, eontainiii';- strata of coarse con^iloinenite. T.l 



12. Shales, dark gray, calcareous ; with impure limestone 5 



11. Sandstone, very soft and white, near toi> pinkish ; massive in i)!aees ; contains 



layers of fine con{>lomerate 50 



Jura (580 feet). 

 10. Clay or marls, yellow, greenish, and gray, sometimes sandy, with streak of 



])urp](^ near top 140 



9.. Sandstone, brown, lamellar 3 



8. Clay or marl, brownish and sandy 15 



7. Limestone, thin stratum, very fossiliferous; from its equivalent in the vicin- 

 ity many fossils wen; collected — 



0. Clay or marl, yellow ; with red sandy clay at base; e.xposures not complete. 235 

 5. Sandstone, yellow, in i)laces(piitered, shaly at the top but lower i);irt massive. .50-75 

 4. Clay or niarl, gray and greenish, with i)iidv streak near the middle; calcare- 

 ous at base, with much ilint ; in an imi)ure limestone occur many fossils .... 120 



Red Beds. 



3. Sandstone, red and soft, with much gypsum 10 



2. Gypsum in layers of 12 inches, interstratified with red sandy clay for a space 



of 15-20 



1. Sandstone, or sandy clay, soft, red to bed of river. . 150 



No. 1 1 in this section will be seen to correspond in position and char- 

 acter Avitli a sandstone in the section on Beaver Creek, and it is included 

 in the Cretaceous, although it has not the common character of the Dakota 

 sandstone. The fossiliferous stratum (in 7) is probably the same as the 

 upper fossiliferous stratum of the Redwater section. That stratum is 350 

 feet above the Red Bed; this, in a thicker series, is 50 feet higher. The 

 Belle Fourche locality yielded — 



Ostrea strigilecula. Tancrcdia corhuUformis. 



Avicula mucronata. Tancredia hulbosa. 



I'mpezium BeUcfourchcnsis. Tancrcdia postica. 



Plcuromya Ntwtoni. Dosinia Jurassica. 



Tancrcdia inornata. Ammonites cordiformis. 



At the base of the yellow calcareous clays (4) forming the bottom of 

 the Jurassic series there is a calcareous layer containing many fossils. 

 Among them are — 



Ostrea strigilecula. Psammohia prematura 



Camptonectes hellistriatus. Belemnites densus. 



Pseudomonotis curta. 



