154 GEOLOGY OF THE YELLOWSTONE NATIONAL PAEK. 



Section of sedimentary rocks in Berry Creek Canyon — Continued. 



Num- 

 ber. Feet. 



' 9 Shales, with thin bands of limestone 30 



8 Shale, green, micaceous ; thin hands of limestone 25 



7 Limestone, light gray ; dense 15 



6 Limestone, massive ledge ; lavender, weathering yellow 12 



Flathead . 5 Limestone, gray, weathering yellow ; splintered vertically 5 



4 Shales, micaceous, calcareous, green 5 



3 Limestone, irregularly and thinly bedded; chocolate colored., 60 



2 Shales ? ; poor exposure 50 



1 Limestone, thinly bedded. Strike N. 50° W., dip 35° NE 35 



The slope of the peak to the east of this canyon is benched in a 

 series of steps, whose upper surface corresponds to that of the limestone 

 beds, but exposures are few and unsatisfactory. The summit of the peak is 

 formed of the cherty Teton sandstone, resting upon the white Quadrant 

 quartzites, which here break into small angular fragments. The northern 

 slope of this peak is open and grassy near the summit, but the flanks of the 

 mountain are thickly covered with young- pines and fallen timber. At the 

 point where Berry Creek leaves its mountain valley to flow in a succession 

 of cascades and rapids through the canyon just mentioned, the Juratrias 

 rocks are well exposed. The highest beds noticed were soft and micaceous 

 shales, which occur beneath the red Teton sandstones. The beds strike N. 

 50° E., and dip 25° NW. The rocks are fissile micaceous shales, contain- 

 ing much pyrite, and near the entrance of the mountain are warped and 

 twisted into a number of small folds. In the upper part of the canyon the 

 granular white limestones, which are generally buff or creamy yellow on 

 fresh fractures and belong to the Quadrant quartzite, are also well exposed. 

 The Quadrant quartzite series is underlain by a streak of reddish magnesian 

 clays, a part of the limestone series that forms the highest beds of the 

 Madison formation. The fossils are of Lower Carboniferous age, and are 

 most abundant above the hard gray limestones which alternate with the 

 red streaks. 



In descending the creek the strike gradually changes from N. 50° E. 

 to N. 30° E., this change occurring within a distance of half a mile. Still 

 farther down, the strike veers rapidly toward the west, and near the junction 

 with Owl Creek it has changed to N. 50° W., which is the general strike 

 of the strata north of Owl Creek, both above and below the mouth of Berry 

 Creek. Below the forks the arenaceous fetid limestones of the Jefferson for- 

 mation extend down the stream until lost in the meadows of Snake River. 



