52 DESCRIPTION OF THE COUNTRY. 
they can be observed. The sandstone of this third division is very much developed, with rather 
an indistinct and very massive stratification. Its thickness is one thousand feet, while the 
variegated marls are only four or five hundred feet thick ; making a whole of fifteen hundred 
feet for the upper group of trias. Upon our route this ibiadstone forms the summits of the 
table-lands or mesas, which extend on each bank of the Canadian river from Antelope Hills to 
the Llano Estacado ; then it forms the bottom of the valleys from Rocky Dell creek and the 
Plaza Larga to Anton Chico and the Cañon Blanco." The fertility of the great basin lying 
between the bluffs of the Llano Estacado and the Canadian, and extending nearly from Rocky 
Dell creek across Plaza Larga, and thence to the head of Pajasito and Cuerbito creeks, may be 
ascribed to the prevalence of a sandy calcareous clay, belonging to the strata of the variegated 
marls, and to the streamlets that issue from the base of the Llano bluffs. Other portions of this 
region, except upon the borders of rivulets or springs, are comparatively barren. 
The Llano Estacado is composed principally of a more recent formation which, by Mr. 
Marcou, is called jurassic. The summit of the first steppe of it, which we crossed, consists of 
a compact white limestone, resting upon white sandstone. The former will furnish lime, the 
latter may be used for masonry. Near Tucumcari mount the mesas are capped by superior 
strata of the same formation, consisting of blue clay, yellowish sandstone, and, at the summit, 
a compact, white, silicious limestone. ‘‘ This formation is not limited to the Llano, but it forms 
the summits of all the plateaux that are seen to the north, in the direction of the Canadian 
river, and between the Canadian and the Raton mountains, as well as the majority of the 
mesas which extend from the Rio Pecos to the foot of the Sierra de Sandia. Our survey has 
also met with it on the other side of the Rio Puerco, forming, with volcanic lava, almost the 
whole road between Covero and the Sierra Madre, and finally, between Inscription Rock and 
the Pueblo of Zuñi, where it again forms mesas, which extend in the direction of Fort Defiance 
and the Cañon de Chelly.” Near several of the points above mentioned ‘there are beds of 
bituminous coal in the clay, but only three or four inches thick, so that probably they would 
not be rich enough to be successfully worked.'' 
In the cañon of San Antonio ‘‘the trias is met with again." It is here ““upheaved and 
dislocated, the strata dipping to the east,’’ and in the descent of the creek ** gypsum, dolomite, 
sandstone, and red clay," are'successively exposed. Near Tijeras, upon both sides of the 
gorge that has been cut through the Rocky mountains, ** black schistose clay is seen, belonging 
to the coal measures; then grayish-blue limestone," containing fossils characteristic of the 
mountain limestone or lower carboniferous. Mr. Marcou remarks that ‘‘the presence of the 
black slate between the mountain limestone and the red clay of the trias indicates the existence 
of beds of coal on several points of the Rocky mountains;’’ and the inhabitants of New Mexico, 
he says, pointed out to him “beds of bituminous coal belonging, without any doubt, to the 
rocks of the coal measures." Similar indications of coal are found at various points of the 
Zandia and Santa Fé mountains, and at the village of Pecos. Several intelligent citizens of 
the T'erritory state that coal has been discovered in considerable quantities near Rio Puerco and 
in the vicinity of Cibolleta, and the quality was such as to cause it to be used in blacksmiths’ 
shops. Some very fine specimens sent to us by Captain Ewell, of the dragoons, have been 
noticed in a preceding portion of this report. There can be no doubt of its good quality, and 
it is believed to be sufficiently abundant to afford a limited supply of light and economical fuel 
for railway engines, or for the uses of the inhabitants. 
The other inineralogical resources of this Territory have, perhaps, been sufficiently referred 
toin the Itinerary. When it is admitted that the mountains extending from the Sierra de Oro, 
near Tuerto, to the Sierra de los Organos, near Las Cruces, contain mines of gold and silver 
that have been successfully worked for centuries by rude and unskilful processes, no one can 
doubt that a railroad to the Atlantic would cause the mining resources of this region to be 
developed, and that the advantages afforded would be reciprocal. Placers and mines are known 
to cover regions extending from the mountains of Taos to El Paso; and, judging from the 
