250 REPORT UNITED STATES GEOLOGICAL SURVEY. 
cliffs and huge outlying masses in the slopes a few hundred yards below 
the summit, while the outcrop of the Potsdam sandstone is traced here 
and there in the débris-covered inner slope descending to the Archean 
basis rocks, rounded elevations of which still retain isolated remnants 
of the Primordial strata. 
The Triassic “‘red-beds ” appear over an outlying parallel belt, half 
to three- quarters of a mile wide, forming picturesque highly- colored low 
bluffs bordering the little valley below the debouchure which widens out 
into the basin through which the stream winds lower down. <A consid- 
erable belt of darkish drab deposits succeeds the “red beds” and. varie- 
gated Jura horizons, which is probably referable to the Colorado group 
of the Cretaceous series. Beyond the latter, to the eastward, the upland 
slopes merge into the Tertiary benches of the basin region, in the midst 
of which occurs the sharp subordinate fold that runs parallel with and 
8 to 12 miles distant from the foot of the mountains. The section of 
the Mesozoic series exposed along tributary drainage depressions north 
of Sage Creek, of which an account is subjoined, affords many interesting 
details illustrative of the variable character of the depositions at locali- 
ties removed but a few miles from one another, contrasting with the uni- 
formity of the conditions prevalent over extended areas during the for- 
mation of the Paleozoic series. 
Section vicinity of Sage Creek. 
Archean. Rusty-weathered gneiss, schists, We. 
. Potsdam sandstone. 
. Quebec group limestones. 
Buif limestone, Niagara ? 
Carboniferous. Magnesian limestone. 
. Drab and gray limestones. 
. Middle Carboniferous. Buff, reddish-stained sandstone. 
. Upper Carboniferous division, including Permo-Carboniterous 
horizon. Gray, rusty-weathered limestones, and drab shales. 
No. 9. Trias. a, deep red arenaceous shales and shaly sandstone, with 
thin layers of gray, greenish-stained sandstone; b, drab, fragmentary 
limestone, 5 feet, +; ¢, reddish arenaceous shales and sandstone, with 
gray layers; d, drab limestone, obscure ledge; e, yellowish, green- 
stained and reddish sandstones, in places conglomeritic. 
No. 10. Drab limestones and chocolate-red shales, forming a well- 
marked horizon. 
No. 11. Buff and reddish variegated sandstones, not clearly exposed. 
No. 12. Jura. a, fragmentary drab limestone, exposed 4 feet, dip. 15°, 
N.H., containing ‘numerous imperfectly preserved specimens of small 
conchifers; b, similar, darker-weathered limestone ledge; no fossils ob- 
served. 
No. 13. Dirty yellow and biuish soft sandstones, capped by a thin layer 
of rusty-gray calcareous sandstone charged with Campionectes, Trigonia 
(?) Rhynchonella, Dentalium (?) &e. Dip, 16°, N. 63° HB. 
No. 14. Drab and reddish shales, in beautiful variegated exposures. 
No. 15. Yellowish sandstones, with concretions, forming arather thick 
bed, followed above by unexposed space. 
No. 16. Gray, rusty-weathered, and buff sandstone, a heavy ledge. 
No. 17. Cretaceous. Dark drab and bluish clays, belongin g toa heavy 
deposit conformable to the preceding and dipping in the same direction. 
No. 18-20, inclusive. Variegated pale red and greenish drab clayey de- 
posits, and dirty yellow weathered horizontal sandstones, belonging to 
A 
SOOM CLs 
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