= B 
New Mevico and California. 379 
first time with granite in situ, the sandstone, if I may judge fi om 
limited examination, was os uplifted and thrown bac! 
angle of nearly one hun degrees 
West of Santa Fe, granite seems. also to prevail. In m ursion 
to the Placers, southwest of Santa Fe, I found sandstone below, and on. 
the height of the mountains granite and trap rocks. 
In the mountains of that neighborhood common limestone and oa 
phate of lime are said to exist; but onthe road over which I travelled 
I had no opportunity to see any. 
Granitic and trap formations seem to: predonsinato; too, in the valle 
of the Rio del Norte below Santa’Fe; ‘but as the road erat ads alwidhs 
ae river, and the mountains .on either side are gene rally about 
often to depend upon the external form of the mountain chain, which | 
apparently indicated unstratified and igneous rocks. Whenever re 
mountains approached the river, I gained more information. Thus 
instance, I found between a ba Joya, (above 115 miles from Sai 
Fe,) ceca sandstone and quartz in a spur of the eastern mountain 
chain; and in Joyita itself tiafl near the river, of amygdaloidal 
asalt. 
Some miles west of Siostte, (140 miles, ) on the right bank of the 
Tiver, {examined the western mountains, and found porphyri itie and 
trachytic roc 
Near the ruins of Valverde, (165 miles;) I met with bluffs of ¢ a dark 
brown, nodular sandstone ; and about eight miles beyond, with amyg- 
daloidal basalt again 
In the Jornada del Mabe; granitic and basaltic formations, to Judge 
from their shape, exist in the distant mountain chains; part of them 
“in the eastern chats is calledj from the basaltic appearance, Organ 
mountains. 
Below Dofana I perceived some primitive rocks again, near the 
river, ene g a decomposed por 
ountains above El Paso belong mainly to the trap formation. 
Ritiog, my short stay in El Paso made an excursion to the south- 
western mountains of the valley, and’ was rather astonished to find 
mountains of limestone. The foot of the mountains was formed by a 
ae * hgh sandstone, similar to that underlying the amygda* 
loidal basalt. The very compact and gray limestone, intersected with 
poses white veins of ane spar, rose upon it to the crest of the moun- 
tains; but in several places, granite and greenstone seemed to have 
burst ‘through it and nas partial eruptions. After a long search I 
discovered some fossils, and though much injured and d in per rfe cotathed : 
fossils are a coral Calamopora), and a bivalve shell of the genus 
Pterinea. This limestone is reg a Silurian rock. Several mines 
have formerly been worked in 
a the road from El Paso to ‘Chibuahua [ met in the first day or two 
write the same limestone. The pieces lying on the were .gener- 
ally surrounded with a white crust of carbonate of lime; pieces, too, 
of what appeared to be fresh-water limestone, occurred. It is rather 
probable that this is the same material with the white crust of the blue 
— and that both are the result of calcareons springs. 
