BT.Jonx] SECTION THROUGH STATION XXIV. 379 



it is connected by a deep saddle, rises a liigli conical peak (about 7,G00 

 feet), the crest of wliicL. is formed by a heavy ledge of hard reddish 

 buff sandstone or quartzite, much broken up by cleavage and joint 

 structure, and dipping southwestward. This ledge runs obliquely down 

 into the cafion on the south, and thence climbs the steep slopes to the 

 crest of the opposite ridge, where it forms another rugged comb outlying 

 the highest summit of the range north of Fall Creek; to the northwest 

 it soon passes into the volcanic mountain-plateau and is soon lost to 

 view. On the southwest flank of this i)eak 100 feet below the summit 

 a similar heavy ledge of darker rusty gray and buif laminated quartzite, 

 or hard sandstone, forms a dike-like comb skii'tiug the hillside, in which 

 a thickness of 20 feet is exposed, dii)ping apparently N. 50*^ E., at an 

 angle of 75^. The relations of this ledge to that occurring in the sum- 

 mit, from which it differs mainly in its darker color, Avere not clearly 

 ilisplayed. In the ridge to the southeast, where its accompanying ledge 

 is well exposed, there is no indication of these strata being folded into 

 a sharp synclinal, and its position here may be duo to disturbances of 

 merely local extent. This peak is about two and a half miles northeast- 

 ward of the previously mentioned trachytic-capped dome on the water- 

 shed equidistant between Stations XXI and XXII. In the interval 

 between these two points, an extremely broken region on the headwaters 

 of Grouse Creek, the same series of strata occur as was noticed in the 

 belt on the northeast flank of the range between Station XX and the 

 Snake, four miles to the southeast of the present locality, and also north- 

 east of Station XXI midway between the two latter points. The inter- 

 val here consists of alternating belts of red shales, reddish and gray, 

 brown weathered sandstones, bluish limestones and light drab calcare- 

 ous deposits, none of which are exposed continuously over any consid- 

 erable area, but appear here and there in isolated patches in the steeper 

 slopes and crests. . The above deposits, extending over to the trachytic- 

 capped dome, are introduced in the following section, connecting with 

 the examined horizons in the section through Station XXI. The present 

 section from the quartzite peak passes along a hne northeast to Station 

 XXIV three-quarters of a mile, thence in a nearly easterly direction 

 four and a half miles, to the nearest point on Snake Kiver, and is as 

 follows : 



Section through Station XXIV. 



a. Eed deposits, occupying a wide belt, and perhajjs identical with 

 bed Xo. 58 of section through Station XXI. 



h. Eed and light-drab deposits, the latter i)robably limestones and 

 indurated calcareous shales. 



c. Light-drab deposits, occurring in a narrow belt, and may be the 

 same as the light band under last above number. 



d. Heavy deposit of red beds, sandstones and shales, apparently dip- 

 I)iug southwestward. 



e. Drab calcareous deposits. 



/. lied deposits, sandstones, &ii. 



1. Quartzitic sandstone, 20 feet exposed ; dip 75°, X. 50° E. 



2. Unexposed space. 



3. Similar quartzitic sandstone, a heavy ledge ; dip southwestward. 



4. Blue and drab shales, with indurated feiTUginous gritty layers and 

 nodules in alternating thin bands, GO feet; dip 45°, S. 40° W. 



5. Dark brown, shaly, ferruginous gritty limestone, underlaid by a 

 greater thickness of gray arenaceous rock, 10 feet exposed ; dip same as 

 last. 



