6T. jomf.] TETON RANGE. 423 



same stratigrapliic featm^s as noted previously in the vicinity of Stations 

 XXXVIII and XXXVII to the north. The summit drab limestones are 

 overlaid, in the crest of the ridge a short distance northwest of the 

 summit, by a thickness of 150 to 200 feet of strata, which show the fol- 

 lowing order of arrangement ; 



Section in crest of Station XLIII ridge. 



a. Hard, pinkish graj", laminated sandstone, 50 to 75 feet ex])oscd. 

 1). Blue and gray limestone, with crinoidal remains ; dip W. 35° !N"., 

 angle 23"^. 



c. Eeddish chocolate, fragmentary limestone, Spirifer and comminuted 

 fossil remains ; thin bed. 



d. Red shale and shaly sandstone, with dark flint flakes.. 

 c. Eougii, cherty, gray limestones; thin bed. 



/. Laminated, gray-buff", reddish stained sandstone, forming a heavy 

 bed capping the ridge at one point. 



g. Drab-blue limestones ; thin bed. 



h. Eed shales and sandstone. 



i. Drab-gray limestones, exposed 400 feet and more in steep slopes 

 descending into ami)hitheatre. 



The above ledges veer round in the crest of the ridge defining the 

 amphitheatre which opens out to the east, the ui)j)ermost sandstone ap- 

 pearing in the slope descending to the saddle connecting this ridge with 

 the higher mountain to the west. In the summit of the latter is plainly 

 seen a remnant capping of dull reddish beds, which may possibly prove 

 to be identical with the red arenaceous horizon above described, rather 

 than referable to the base of the Trias " red beds." The southeastern 

 face of this mountain shows a fine exhibition of the Carboniferous Ume- 

 stone ledges, 800 feet or more iu thickness, and which, as before stated, 

 curve round from the northwest to the south where they abruptly dip in 

 the steep slopes bordering West Pass Creek. The accomi^anying sketch 

 conveys at a glance the relative position of the strata in the latter moun- 

 tam, as seen from the south flank of Station XLIII, the (.lifference in 

 altitude of the two mountains being about 220 feet. 



Looking northward from Station XLIII, the eye takes in at a glance 

 the great sedimentary ridges which here span the range, terminating in 

 the chain of lofty summits which crown the eastern barrier, which ab- 

 ruptly descends into Jackson's Basin. The western foreland here, as 

 farther northw' ard, terminates in ridges whose eastern face falls away in 

 a succession of escarj)ments and steep slopes into amphitheatres in which 

 the west-flowing streams take their rise. But in this section the amphi- 

 theatres are much restricted, and the drainage channels are canoned in 

 the sedimentary deposits, rarely, indeed, cutting their beds through to 

 the Archaian basis, which only appears in force in the mountain wall 

 rising from Jackson's Basin. While in the north the continuity of the 

 sedimentary beds may be traced for miles in the foreland escarpments 

 and in the great pier-hke ridges separating the Alpine basins, in the 

 latter region these same deposits are thrown into an assemblage of 

 rugged ridges ami mountain blocks which almost defy the recognition of 

 the various formations from any one point of view over so extensive 

 and broken a field. This is mainly due to the fact that these deposits 

 are much disturbed by minor and more or less local undulations, which, 

 in comparatively short distances, cause the same beds to appear at very 

 different relative levels, w^hile the repetition of similar lithological condi- 



