68 EXPLORING EXPEDITION FKOM SANTA FE 



of the country, joined to his unextinguishable enthusiasm and good nature, made him 

 an invaluable companion in our explorations during the time that he accompanied us. 

 A 3 these deposits of copper are matters of some geological interest, I take the liberty 

 of transcribing from my journal the description of our visit to the "Cobre" of Abiquiu. 



"July 17. Started this morning, with Mr. Pfeiffer and several members of our 

 party, for the copper mines, situated some nine miles north of Abiquiu. As we rose 

 from the valley, we were gratified by the most charming view we had yet beheld in 

 New Mexico. The alluvial bottom-lands, covered with groves of vivid green cotton-. 

 Avoods, alternating with fields of wheat and corn, interspersed among which were the 

 white-washed adobe houses of the residents, each with its walled corral, its garden, 

 and its clumps of apricot-trees, formed a scene of fertility and rural beauty rare enough 

 in a country whose sterility is proverbial. Above the valley rose the frowning battle- 

 ments of the trap mesas, which sweep around the foot of the Vallcs, and the rough 

 and rocky slopes stretching up to their lofty and picturesque summits. In another 

 direction were above, the peculiar outline of Abiquiu Peak, and below, the rocky gate 

 from whidi the river issues. 



"Leaving the Chama, we passed up the eroded valley of an intermittent tributary. 

 This is excavated in the Triassic series, and its sides exhibit bands of brilliant color, 

 red, orange, blue, white, &c., as vivid as could be drawn from an artist's color-box. 

 In some localities the red sandstones usually soft and fine-grained are replaced In- 

 coarse conglomerates or masses of cemented bowlders, generally of large size. These 

 bowlders .are composed of quartzose and syenitic rock, hard and smoothly rounded. 

 They indicate stronger currents and more violence of action, during the deposition of 

 the Trias, .than in any other locality where I have observed it; also, closer approach 

 to the source of the material of which these beds are composed. Ascending the arroyo, 

 toward its head, we found the strata rising rapidly toward the north, and cut through 

 so as to expose the saliferous sandstones the lowest member of the Trias in sections 

 of at least 200 feet. This group here consists of thick-bedded, chocolate sandstones, 

 like those of New Jersey and the Connecticut Valley, except that here and there they 

 showed large patches of white, interstratified with green and brown shales. Here, as 

 on the Little Colorado, this formation contains much saline matter, as shown by num- 

 erous salt springs and a white saline efflorescence on the surfaces of the rock itself. 

 The Cobre is situated in the face of the cliff's, bordering an eroded valley drained into 

 the Chama below Abiquiu. These cliffs are composed at base of the saliferous sand- 

 stones and interstratified marls, some 250 feet in thickness; above these, blood-red 

 marls and calcareous sandstones, 200 feet thick; the whole crowned by coarse yellow 

 sandstones, having a thickness of about 150 feet; a section corresponding to that on 

 the Pecos, but exhibiting a much less thickness of the red marls and calcareous sand-, 

 stones. The copper occurs in the base of the yellow sandstones just above the marls. 

 To reach the most important of the ancient mines of this vicinity, we climbed up the 

 face of the southern cliff's of the valley, over the red sandstones and marls, till we 

 reached the coarse yellow sandstones which overlie them. Here we found an entrance, 

 five by six feet in dimensions, which led to a scries of galleries, having a. combined 

 length of perhaps a hundred yards. The work exhibits considerable skill in the use 



