462 REPORT UNITED STATES GEOLOGICAL SURVEY. 



400 to 500 feet of strata is exposed above the water-level, showing the 

 basis rocks of the adjacent hills. A section at this locality is given below, 

 the thicknesses of the beds estimated. 



Section in bluffs on Buffalo Fori:, foot of Station XLVIII. 



1. Buff-drab clays, indurated arenaceous and argillaceous layers below, 

 60 feet. 



2. Buff sandstone, exposed 2 feet. ' 



3. Buff and ash-colored clays, darker drab below, 70 feet. 



4. Buff sandstone, exposed 2 feet. 



5. Slope, with indications of buff-drab clays, 65 feet. 



6. Dirty buff sandstone, exposed 5 feet. 



7. Light drab clays, 60 feet. 



8. Dirty buff sandstone, exposed 4 feet. 



9. Space, with drab clays, 40 feet. 



10. Busty brownish sandstone, exposed 3 feet. 



11. Space rising into crest of ridge, probably ash-colored clays, 100 

 feet or more. 



The edges of the strata in the above exposure appear nearly horizontal, 

 or slightly incliniug upstream; but the dip is to the northeastward at an 

 angle of from 10° to 15°. There are no indications of lignite seams at 

 this place, although the beds belong to the Tertiary series on the south, 

 noticed in a preceding page. A hasty search in the beds at this locality 

 failed to discover the vestige of organic remains ; but at a point some 

 distance above in the foot of the same line of bluffs, indurated bluish- 

 drab argillaceous layers, probably belonging to the horizon of No. 1, 

 afforded one or two varieties of dicotyledonous leaves. 



From the crest of the river bluff the surface slopes into a parallel 

 drainage depression, connected with the hills to the north by a saddle 

 flat, in which a grass-fringed pond was found, its outlet dammed by the 

 work of beavers. The opposite slope rises in successive steep ascents 

 and high terrace platforms into the summit of a cluster of wooded hills 

 in the Buffalo Fork and Pacific Creek divide, on one of the outer knobs 

 of which Station XLVIII was located at a height of about 2,000 feet 

 above the former stream. The rock exposures observed in the southern 

 slope of the mountain, where they are much hidden by debris and under- 

 growth, present the following section of superimposed strata in contin- 

 uation of the bluff exposure. 



Section in south slope of Station XLVIII. 



12. Space between foot of main slope and outlying river -bluff. 



13. Thin bed of buff-gray sandstone in foot of declivity opposite pond, 

 about 250 feet above river-level. 



14. Unexposed space. 



15. Buff-gray, shaly sandstone, 2 feet exposed, at elevation of about 

 360 feet above the river. 



16. Slope, unexposed, covered with gneissic and other water-worn 

 bowlders. 



17. Thin-bedded, buff sandstone, exposed 5 feet, elevation 450 feet. 



18. Unexposed slope. 



19. Buff-gray sandstone, obscure exposure, elevation about 540 feet. 



20. Broken slope about three-quarters of a mile across, thickly wooded 

 in part, and covered with drift materials of all sorts, with traces of brown 

 earth in open, sage-grown spaces. 



