30 
GEOLOGICAL REPORT—THIRTY-FIFTH PARALLEL 
four to six feet thick. Beds of sandstone also occur, and these are rose-colored and very hard. 
(See notes October 10th.) No coal was found, hut its presence further south in the Manzana 
mountains is mentioned. The following are the fossils noted in these carboniferous rocks : 
Productus giganteus and punctatus, Terebratidce, Spiriferce, Orthocera, Zaphrentis, and Crinoids. 
ALBUQUERQUE AND THE SANDIA MOUNTAINS. 
These observations on the limestone were made on the day of the ascent of the range, hut the 
same strata were seen and notes made upon them at their exposure further south, and along the 
line of the trail passing eastward from Albuquerque towards San Antonio and San Pedro. 
After leaving Albuquerque and passing for two miles over alluvial deposites, outcrops of granite 
were found, three miles wide ; and resting on this granite were thick strata of limestone, dipping 
eastward at an angle of 35 or 40 degrees, the heads of the beds being turned to the west. 
This is interstratified with thin and black clay shales. Productus giganteus and punctatus a 
Spirifer, and two Terebratidce and Polypes , were found here. 
Mr. Campbell informs me that the fossils are very abundant near the trail, andean he readily 
knocked out of the limestone with a hammer. 
This limestone is said to border the trail on the right for a mile or more. The limestone 
was met with again a short distance beyond San Pedro, and it dips to the east, as before. 
This is very probably the same outcrop of limestone which contains veins of copper and lead 
ore, and which is found on the trail between San Pedro and Tuerto. The mines in this 
limestone v ere visited by Lieutenant J. W. Abert in 1846, and he obtained from the rock a 
Terebrutula, which is figured in his report. 1 
The next, and perhaps the most interesting locality of this carboniferous limestone, is at the 
eastern base of the southern end of the Santa Fe range, at the Pecos villages, so well known 
and celebrated as the former residence of the descendants of the Montezumas, who kept their 
sacred fire constantly burning until within a few years. At this place—at New and Old 
Pecos—Mr. Marcou examined the limestone and obtained numerous fossils. These are in the 
collection, (see Nos. 114 to 122,) and have been examined and described for me by Professor 
Hall, of Albany. These descriptions, and the figures of new and important species, are given 
in a subsequent portion of this report. These fossils are all very perfect, and from the number 
collected, I judge that they are very abundant and easily procured. 
Lieutenant Abert mentions the abundance of fragments of hard limestone along the road 
between Sepullo creek and Vegas, and this renders it probable that the limestone is considerably 
1 Report of a reconnoissance in New Mexico, by Lieutenant J. W. Abert. 
