st.joitc.] SECTION. 431 



13. Greenish gray soft sandstone, alternating with rusty red shales 

 and "brown-stained gray sandstone. 



14. Gray and reddish-buff sandstone, interbedded with dark choco- 

 late-colored and reddish indurated shales, with ferruginous nodules and 

 drab, chocolate-stained limestone layers. The lower exposed portion of 

 the deposit consists of a hard, laminated, reddish-gray sandstone asso- 

 ciated with a dark brownish red conglomerate, dipping 55°, W. 



15. Drab limestone, in heavy and thin-bedded layers, dipping 45° to 

 55°, S. 50° to 70° W. This limestone forms a heavy deposit, resting 

 upon the last described sandstone, appearing in the summit of the east 

 spur of Station XLII ridge and heavily flagging the slope descending 

 to the saddle which connects the spur with the above mountain ridge. 

 Certain layers of the limestone contain numerous individuals of a small 

 undetermined Gasteropod, which was the only fossil observed. 



16. Brown, gray, and pink sandstone, with joint structure ; forms a 

 heavy bed in the east side of the saddle, dipping towards the mountain, 

 or W. 10° S., at an angle of 47°. 



17. Variegated blue and chocolate-colored arenaceous shales, occupy- 

 ing the depression in the saddle, one and a half miles east of Station 

 XLH. 



18. Heavy-bedded drab limestone. In climbing from the above-men- 

 tioned saddle to the west of the southeast continuation of Station XLII 

 ridge, the above limestone appears in heavy ledges mailing the steep 

 northeast face of the mountain, where the ledges appear to incline to 

 the eastward at an angle of 65°. Higher in the slope at this point the 

 surface is strewn with the fine angular debris of reddish-gray very hard 

 siliceous deposits, or brittle quartzitic sandstone, apparently forming a 

 heavy ledge, the relation of which to the limestone was not satisfac- 

 torily shown. But in passing up the ridge towards its culminating 

 point, the crest of the mountain was found to be capped by a heavy 

 deposit of darkish and light-drab, spar-seamed, cherty limestone, some- 

 times brecciated, which afforded a few characteristic Carboniferous corals 

 (Zaplirentis and IAthostrotion), overlaid by alternations of heavy buff- 

 pink siliceous beds and thinner limestone layers, all clipping S. 30° W. 

 at angles of 35° to 45°. The latter beds are indicated in the section- 

 diagram under Xos. 19 and 20. 



The main ridge which culminates in Station XLII, thus forms a 

 monoclinal crest extending three or more miles in a general northwest 

 and southeast direction. Under the summit the northeast face presents 

 exceedingly steep slopes descending into amphitheatres, whose beds are 

 choked vfith debris accumulations and furrowed by the drainage ravines 

 which descend into the basin area. In this northeast wall a thickness 

 of 400 feet or more of the Carboniferous limestone is exposed before 

 the slope merges into the steep talus at its foot, which effectually 

 conceals the inferior deposits. On the opposite hand, the ridge more 

 gently slopes into a parallel depression, over the before-mentioned sili- 

 ceous deposits, which latter, doubtless, are as fully developed at this 

 locality as they were found in the ridges north of Station XL. In the 

 opposite acclivity the "red beds" appear in equal force, broad patches 

 of the brilliant color contrasting with the rich green herbaceous growth 

 which here as elsewhere flourishes in the soil based upon these deposits. 

 The latter are succeeded by the drab beds of the Jurassic, which rise up 

 into the crest of a higher mountain a couple of miles south of Station 

 XLII, where they are capped by a heavy rusty ledge which may be 

 traced several miles to the northwest descending into the deep valley at 



