SECTION OF COLORADO CANON. 5D 
Near the mouth of Diamond river, by the intersections of the numerous cafions which cut 
the plateau, portions of it have been left in a series of pinnacles and pyramids, frequently stand- 
ing entirely isolated, forming some of the most striking and remarkable objects seen on our 
expedition. Many of these buttes exhibit a singular resemblance to the spires and pyra- 
mids which form the architectural ornaments of the cities of civilized nations, except that 
the scale of magnitude of all these imitative forms is such as to render the grandest monuments 
of human art insignificant in comparison with them. 
The section exposed in the walls of the cafion of the Colorado in this vicinity consists of 
* the following geological elements : 
SECTION OF CANON OF COLORADO RIVER AT CAMP 67. 
Feet. 
Ist. Bluish-gray limestone, containing corals, casts of Huomphalus, Spirifer, &c.. with 
nodules of chert and i ITON, tO SUMMIt+--. ++ cree ceeweecessceere e918 we =e esas 1,000 
2d. Mottled, red and gray, silicious limestone, interstratified with argillaceous and sili- 
cious shales, red, white, and brown, much changed by infiltration of silica; cavi- 
ties and joints filled with chalcedony vce nha iele 3 lelehe eteligh o-0'die-s Aue dy aie a eh ees 800 
3d. Red, green, and yellow shales, with bands of argillaceous iron, and black oxide 
MANGANESE +++ + eee ee cee eee nee eee ee eee eee ee wees wee eee ween eee eens 100 
4th. Red and brown limestone in thin layers, with grits and shales containing imper- 
fect corals. .... sei pa 0 WM baa sain SRR ke eh tend e kowik ako eam ice ee we Cee 60 
Gin. Groen shalea: oc. oo se ck oo o's ave 6 one oss ack eee ck ee ee 50 
6th. Ferruginous limestones, shales, and mud rocks, the limestones containing corals, 
(Chaetetes ?) greenish shales, with mud furrows and carbonaceous particles, closely 
resembling rocks of Chemung group in New York---+++++++ cesses sees eevee 75 
Tth. Mottled, red and blue, thick bedded limestone; red portions having the form of 
branching OOPS +: « divi ss is.a: ain eeced e004 WN ne eb T eee Oe eee ele 25 
Sth. Soft ochery sandstone «x # +: ci0-+4 ewes « ccbbie tw reiealle mauaihie oo eee elewle cpt eeicwie 25 
9th. Shales with bands of limestone and grits, without fossils-------+++.+++..-5-- 180 
10th. Speckled, white or brown, and dark red foliated sandstones with shales---..--. 260 
llth. Red, gray, and green shales with mud furrows, resembling casts of worm holes. 250 
12th. Gray Goarse SULCIO@HS BANGSLOUR Rs iss 6565 oi < we sie 5s eer bs Shit 0 el 6k ws SS SLE oie ELS 160 
13th. Red quartzose sandstone, often purple, and beautifully striped-.--..- teers eee 150 
14th. Conglomerate «+++... ses ees cence e come ee meee e eee ees wee eee peeeee sane wens 3 
15th. Massive black and white granite, traversed by veins of quartz ee red syenite, 
and coarse red felspathic granite with large plates of silver mica-------+-++-+ 600 
In the absence of fossils it is impossible to determine the precise geological age of any of 
the strata composing the preceding section below the limestone which forms the summit of the 
cliffs. There is some doubt whether this rock is the equivalent of the mountain limestone. The 
fossils procured from it are few, and not well preserved, but they are apparently quite different 
from those of the next great calcareous stratum lying several hundred feet above it, which, 
though hitherto considered by some who have written upon the geology of New Mexico, as the 
lower carboniferous or Mountain limestone, is doubtless not older than the era of the 
measures. The entire thickness of the upper limestone is, as we shall hereafter see, 
probably not less than 1,500 feet. 
The next 500 feet of the section is made up of shales with bands of limestone and grits, 
which have been considerably changed by silicious infiltration. They have apparently been 
much hardened by the process; and their cavities and fissures are filled with masses or plates 
of chalcedony. Concretions of iron and manganese seem to be characteristic of group No. 3. 
Fossils have existed in these strata, but only obscure traces are now discernible. 
