ST. JOHN.] EAST FLANK SOUTH OF CAMPBELL’S FORK. 243 
No. 11. Light-drab arenaceous clays, 75 to 100 feet. 
No. 12. Triassic “red beds,” composed of red shaly sandstone and 
arenaceous clays, with bands of gray sandstone, thin laminze of gyp- 
sum, and above thin tufaceous limestone layers; the formation attain- 
ing a thickness probably in the neighborhood of 800 feet. 
No. 13. Buff sandstone and chocolate-red variegated arenaceous clays, 
Jura-Trias passage beds, 100 to 200 feet +. 
No. 14. Jurassic, possibly including Cretaceous strata above, and 
showing the following lithologic members as made out at a distance: a, 
variegated chocolate-red deposits; b, buff or yellow clays and sand- 
stones; ¢, drab clays; d, soft buff deposits; e, dark chocolate-red 
variegated clays, &c.; jf, soft yellow deposits; g, chocolate or purple 
red variegated clays; h, drab clays; 7, purple-band clay; k, dirty 
brown-yellow clays and sandstones. 
No. 15. a, soft, light-buff deposits, apparently unconformable to the pre- 
ceding, and relations to following not clearly apparent; b, pale-red and 
drab banded Wind River Tertiary deposits, clearly non-conformably su- 
perimposed upon No. 14. 
No. 16. Conglomerate and tufaceous limestone deposits of modern or 
possibly Pliocene date, consisting of: a, chocolate-drab mottled clays, 
5 feet +, apparently an irregular deposit filling inequalities in the 
eroded surface of Trias ‘‘red beds” and forming floor of conglomerate; 
b, conglomerate, here made up of water-worn pebbles chieily of limestone, 
fewer sandstone and Archean rocks, usually in thin, moderately com- 
pacted layers, alternating with red, coarse-sandy clays, 10 to 15 feet; 
e, tufaceous limestone, varying from rather compact to porous laminated 
rock, with calcite concretions, and with conglomeritic layers above and 
below, 50 to 55 feet. These deposits conform to the gently inclined sur- 
face of the previously eroded older rocks, upon which they were un- 
conformally deposited. 
Below Campbell’s Fork about three miles a beautiful little stream pene- 
trates across the great sedimentary mountain ridge, its sources lying in 
a basin well within the Archean area, where the latter rocks are revealed 
over extensive glacial surfaces. The debouchure, which has an altitude 
_ of about 7,600 feet, is flanked by high bluffs of Middle Carboniferous 
sandstone, which here probably reaches athickness of 500 or 600 feet, and 
rising up on the mountain side at angles of 10° to 14°. Ascending the 
stream, which occupies a widish mountain valley, successively lower 
strata in the geological series appear in the lower slopes until the Arch- 
gan basis rocks are encountered three or four miles above the debou- 
chure. Here the stream at once becomes a wild mountain brook filled 
with dark pools and picturesque cascades. A couple ofmiles above the 
entrance the bed of the valley is blocked up by the massive Carbonifer- 
ous magnesian limestone horizon, across which the stream has worn a 
tortuous narrow cleft 50 to 100 feet in depth and in places scarcely 10 
feet in width. The walls show beautiful examples of the erosive action 
of running water, the overhanging cliffs in places intercepting the view 
of the swiftly gliding water in the depths of the chasm. The limestone 
ledges still bear evidences of glaciation in characteristic rounded, smooth- 
surface contours. The gorge is doubtless of post-glacial origin. The 
strata appearing in the precipitous sides of the valley are comparatively 
moderately inclined, the dip ranging from 10° to 15° off the mountain 
flank or northeasterly. Ata point well up that part of the valley tra- 
versing the sedimentary ridge, the strata present a low subordinate 
flexure, the recurrence of which farther south will be noticed farther on. 
The mountain-foot is denuded of the upper members of the Carbonifer- 
