94 GEOLOGY. 
pebbles once contained in it. All of the garnets and beryls found here are more or less worn and 
broken, showing the attrition they have suffered in their transportation from some remote 
source 
The road leading from Fort Defiance to Albuquerque emerges from the valley through a 
cafion cut in its eastern wall; of which it affords a remarkably interesting section. The softer 
portion of the variegated fie is concealed beneath the alluvial surface, but the silicified 
wood which they formerly contained is scattered about in the greatest profusion. The indu- 
rated marls or soft calcareous sandstones which overlie them form a great number of detached 
pinnacles, and the lower portion of the first bluff bordering the great valley. They here pre- 
sent nearly the same characters as at Camps 91 and 92 and in the Navajo valley, but are some- 
what more massive, and their colors less varied. Their aggregate thickness is from four to 
five hundred feet, of which the lower two-thirds is of a nearly uniform rose-red color. The 
upper third is pinkish-white or greenish. 
The sugamit of the cliff is formed by a stratum of yellow sandstone, precisely like that of 
Camps 92 and 93, (Moo-sha-na-ve.) It has a thickness of nearly one hundred feet, and is con- 
formable to the rocks below. With them, it dips so rapidly to the east that, within less than 
half a mile, it comes down to the road we travelled. Before reaching that level, however, it is 
covered by a second cliff, which rises over it to fully the height of the first. This is composed 
exclusively of Lower Cretaceous strata, light yellow sandstones, with green and gray shales, the 
precise counterparts of those forming the mesa of the Moqui villages. Like those of the first 
cliff, these strata are inclined at an angle of 15° with the horizon, and soon disappear beneath 
the surface. 
At this point is a line of fracture running north 26° east; and immediately beyond the place 
where the highest member of the preceding series sinks from view we entered a group of 
rounded hills, also composed of Cretaceous strata, a continuation of the section afforded in the 
cliffs described, but lying nearly horizontal. These consist of green and dove-colored shales, 
brown and greenish sandstones, brownish-yellow concretionary limestone containing Gryphea 
Pitcheri, and beds of lignite. For several miles the trail winds about among hills of these 
materials, in which the lignite beds are very conspicuous. In many places they have been 
burned out, probably by spontaneous combustion, and have changed the color of the contiguous 
shales to a bright red. The strata in immediate contact with them are often converted into 
red or black scoria, which is scarcely distinguishable from that produced by volcanic action. 
The lignite of this vicinity is generally brown in color, less dark and compact than that of 
Camp 92, but similar to that in the upper part of the Lower Cretaceous series north of the 
Moqui villages 
This formation extends with little variation to, and beyond, Camp 104; where, after ascending 
for some miles, we had passed over at least two hundred feet of strata, consisting of a repeti- 
tion of those I have enumerated, and had reached a higher point in the geological scale than 
anywhere on the Moqui mesa. The uppermost member of the series is a brown somewhat 
concretionary silicious limestone overlying a soft, yellowish, thick-bedded sandstone. Both 
these rocks are precisely like many of the strata immediately below them, and equally like 
those of the upper portion of the Moqui mesa north of Oraybe. 
After leaving Camp 104, we descended into a valley through which flows at certain seasons 
a tributary to the Little Colorado. At this point we crossed another line of fracture, twenty 
miles distant from the former one, the strata throughout the interval between them having @ 
_ slight easterly dip. Here they have for a short distance a strong reversed dip, and a mesa 
south of the trail shows an anticlinal axis. This line of disturbance is, however, soon passed, 
and the Cretaceous rocks, similar to those about Camp 104, fall back to the position they there 
held, sated for several miles eastward, with a slight dip in that direction. 
_ At Salt Spring we crossed another marked line of fracture and dislocation, which affords one 
