414 COSMOS. 



approaching the Rocky Mountains from the east, belong 

 perhaps to old eruptions of the Cerrito, or of the stupendous 

 Spanish Peaks (37 32'). This easterly volcanic district of 

 the isolated Raton Mountains forms an area of 80 geogra- 

 phical miles in diameter ; its centre lies nearly in latitude 

 36 50'. 



On the western slope most unmistakeable evidences of 

 ancient volcanic action are discernible over a wider space, 

 which has been traversed by the important expedition of 

 Lieutenant Whipple throughout its whole breadth from 

 east to west. This variously shaped district, though inter- 

 rupted for fully 120 geographical miles to the north of the 

 Sierra de Mogoyon, is comprised (always on the authority 

 of Marcou's geological chart) between latitude 33 48' and 

 35 40', so that instances of eruption occur further south 

 than those of the Raton Mountains. Its centre falls nearly 

 in the parallel of Albuquerque. The area here designated 

 divides into two sections, that of the crest of the Rocky 

 Mountains nearer Mount Taylor, which terminates at the 

 Sierra de Zuni, 30 and the western section, called the Sierra 

 de San Francisco. The conical mountain of Mount Taylor, 

 12,256 feet high, is surrounded by radiating lava-streams, 

 which, like Malpays still destitute of all vegetation, covered 

 over with scoriae and pumice-stone, wind along to a distance 

 of several miles, precisely as in the district around Hecla. 

 About 72 geographical miles to the west of the present Pueblo 

 de Zuni rises the lofty volcanic mountain of San Francisco 

 itself. It has a peak which has been calculated at more 

 than 16,000 feet high, and stretches away southward from 

 the Rio Colorado Chiquito, where, farther to the west, the 



20 We must be careful to distinguish, to the west of the mountain- 

 ridge of Zuni, where the Paso de Zuni attains an elevation of as much 

 as 7943 feet, between Zuni viejo, the old dilapidated town delineated 

 by Mollhausen on Whipple's expedition, and the still inhabited Pueblo 

 de Zuiii. Forty geographical miles north of the latter, near Fort 

 Defiance, there still exists a very small and isolated volcanic district. 

 Between the village of Zuni and the descent to the Rio Colorado 

 chiquito (Little Colorado) lies exposed the petrified forest which 

 Mollhausen admirably delineated in 1853, and described in a treatise 

 which he sent to the Geographical Society of Berlin. According to 

 Marcou (Presume explic. d'une Carte Geol., p. 59), fossil trees and ferna 

 are mingled with the silicified coniferse. 



