er.jomf.] LINCOLN AND BLACKFOOT DIVIDE — SECTION. 333 



have intimate relationsliip with the deposits so obscurely exposed in 

 Lineohi Valley. 



The section extending across the synclinal divide, from a point near 

 our southern boundary, northwesterly to the head of Lincoln Valley is 

 shovra in an accompanying plate, which gives such stratigraphical de- 

 tails as came under notice in this part of the ridge. The section does 

 not, however, pursue a direct course, but it is carried by a series of off- 

 sets northwesterly and at right angles to the strike of the strata, which 

 was made necessary by the form or direction of the divide. 



Section across the Boss Fork — Lincoln and BlacJcfoot divide. 



1. Calcareous spring-deposit, evidently quite extensive accumulations 

 in the borders of the little basin. 



2. White and buff heavy-bedded sandstone, exposed in bluffs short 

 distance below the Eoss Fork road. Dip 25°, W. 20° N. 



3. Drab-gray, laminated, fragmentary limestone, lower layers light and 

 gritty, iuterbedded with buff sandstone. Dip 25°, W. 15° i^. 



4. Shaly brown-buff, gritty layers and hard sandstone. 



5. Gray and dark drab fragmentary Hmestone. Contains a small 

 coral hke Stenopora, also obscure Lamellibranchiates, a small Pleiiro- 

 pJiorus and ScMzodus (f). These fossils possess a Permo-Carboniferous 

 facies, though they may be found to be associated with others of Upper 

 Coal-measure species. This limestone forms a heavy ledge. 



6. Limestone like the above, with black chert. 



7. Space covered with limestone debris. 



8. Light-grayish buff and reddish heavy-bedded sandstone. Dip 30°, 

 W. 30° N. 



9. Sandstone, obscure exposure. 



10. Bnff, reddish-brown weathered, very hard sandstone, 8 to 10 feet 

 exposed. Dip 25° to 30°, W. 15° X. 



11. Gray, buff-yeUow, and brown standstone, interbedded with gray 

 limestone. A heavy deposit. 



12.. Heavy bed of gray limestone. 



13. Heavy deposit of buff sandstone, generally heavy bedded and 

 sometimes granular, with ripple markings and slickenside surfaces. 

 Dip 30° to 50°, W. 25° 'N., curving up into part of an arch. 



14. Obscure ledges of sandstone and possibly limestone. 



15. Gray, gritty, fetid limestone, obscure exijosure, 



16. Brittle, buff sandstone, dii)s steeply westward. 



17. Gray limestone with black chert. Dip 00° westward. Contains 

 casts of fossils, an Aviculopecten f and two or three other forms of Lamelli- 

 branchiates, Dentalium f and one or two smaU forms of Gasteropods, the 

 whole group bearing Jurassic facies, but specifically indeterminable. 



18. Soft, reddish-buff sandstone and limestone debris. 



19. Buff", rusty, rough- weathered sandstone, obscure exposure. 



20. Gray and yellow shaly limestone, fragmentary. 



21. Drab and dark-gray shaly hmestone and buff" sOiceous limestone, 

 obscure exposure. Dip 20° to 30°, W. 5° N. 



22. Eeddish sandstone and hmestone layers and debris. 



23. Gray magnesian ? hmestone, with black and pink chert. Dip 25°, 

 W. 



24. Space, covered with rock debris. 



25. Gray, chocolate weathered, fragmentary limestone. Dip 47°, W. 

 25° S. Contains a small Lingula and an obscurely preserved smaU, 

 coarsely concentrically ribbed LameUibranch, possibly Trigonia. 



