bt.johx.J LINCOLN AND BLACKFOOT DIVIDE — SECTION. 333 



have intimate relationship with the deposits so obscurely exposed in 

 Lincoln Yalley. 



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

 onr southern boundary, northwesterly to the head of Lincoln Yalley is 

 shown in an accompanying plate, which gives such strati graphical 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 Blaclifoot divide. 



1. Calcareous spring-deposit, evidently quite extensive accumulations 

 in the borders of the little basin. 



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

 distance below the Boss Fork road. Dip 25°, W. 20° K 



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

 gritty, interbedded with buff sandstone. Dip 25°, W. 15° jST. 



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



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

 coral like Stenopora, also obscure Lamellibranchiates, a small Pleuro- 

 plwrus and Scliizodus (!). These fossils possess a Permo-Carboniferous 

 fades, 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° K 



9. Sandstone, obscure exposure. 



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

 exposed. Dip 25° to 30°, W. 15° 1*. 



11. Gray, buff-yellow, 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° IN"., curving up into part of an arch. 



14. Obscure ledges of sandstone and possibly limestone. 



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



16. Brittle, buff sandstone, dips steeply westward. 



17. Gray limestone with black chert. Dip 60° westward. Contains 

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

 branchiates, Dentalimn ? and one or two small 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 limestone and buff siliceous limestone, 

 obscure exposure. Dip 20° to 30°, W. 5° 1ST. 



22. Beddish sandstone and limestone layers and debris. 



23. Gray magnesian % limestone, 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 small, 

 coarsely concentrically ribbed Lamellibranch, possibly Trigonia. 



