THE LOUP FORK BEDS. 
21 
marls, as already described by Dr. Hayden. The erosive forces have cut 
deep valleys and gorges from their mass, leaving tremendous castellated 
and bastioned escarpments of a thousand feet elevation. Interesting views 
of these beds may be had by following the valley of the Embuda Creek, 
and the canadas which extend from it to the southward and eastward. After 
careful examination of this region, I could only find a single fossil, namely, 
a penultimate phalange of a lateral digit of probably a three-toed horse. 
Crossing the Rio Grrande by a ford not far from the mouth of the 
Embuda Creek, I climbed the rugged face of the lava mass that forms the 
sides of the canon of the river, and which underlies the surface on its eastern 
side, and found myself at the base of the “Pliocene” sands, which there 
form bad-land hills of some elevation. Some of them are worn into castel¬ 
lated forms of much beauty; one in particular reminding me of the Eocene 
Church Buttes of Wyoming. From their summits, an extensive view was 
had of the triangular area inclosed on two sides by the Rio Grande and 
the Rio Chama, with the two drainage-areas of the Ojo Caliente and El 
Rito Creeks. On traversing this region, it was found to be entirely com¬ 
posed of the “Pliocene” sands, and to be very arid, with cedars scattered 
irregularly over the surface. The springs of Ojo Caliente number three, 
the most important issuing from a vertical ledge of gneiss, which is there 
traversed by a wide quartz-vein. The temperature of the warm springs is 
from 116° to 120°; they contain abundance of a Confervoid Alga. In the 
creek below, I saw a Cyprinoid Fish i^Gila pandora, Cope), taken with the 
hook. Near to this point I first observed the Blue Partridge {Callipepla 
squamata, Vig.), which is readil}^ distinguished, as it runs, by the white under 
side of its erect top-knot. 
In descending the Rio Chama, the arenaceous bluffs are continually in 
view on the north side, and occasionally display layers of basalt alternating 
with the sandstones. In this situation, the basalt is at times concretionary. 
The bed which bounds the Rio Grande on the west terminates at the junc¬ 
tion with the Chama in a high point. On the soutliAvest side of the Chama, a 
similar stratum gives the mesa-form to the hills, nearly to its mouth. South 
of these, the Jemez Mountains rise in impressive proportions, and, extend¬ 
ing southward, bound the Rio Grande Valley on the west. 
