REPORT 



ON THE 



GEOLOGY AND MINERAL RESOURCES 



OF 



TRANS-PECOS TEXAS 



BY W. H. VON STREERUWITZ. 



CHAPTER I. 



The present Report refers principally to the area mapped, topographically, 

 between longitude 104° 55' and 105° 35' and latitude 30° 55' and 31° 10', 

 covering the east and west slopes of the Quitman Mountains (formerly Sierra 

 de los Dolores) to the El Paso stage road; the Malone Hills; the southwestern 

 part of the Sierra Blanca group, with Sierra Blanca Peak; the southwestern 

 spur of the Sierra Diabolo; the western part of the Oarrizo Mountains; and the 

 northern foothills of the Eagle Mountains (Sierra del Cola del Aguila); the 

 hills of the Devil's Ridge (sometimes called the Devil's Backbone); and the hill 

 ranges between the Sierra Diabolo, Carrizo, Eagle Mountains, and the Quit- 

 man Range, with the intervening extensive flats. It refers also, as far as geo- 

 graphy is concerned, to a part of the Trans-Pecos Texas which up to this 

 time has not been worked up topographically and geologically, but which I 

 have touched by reconnoitering, such as the Guadaloupe Mountains, extending 

 southward from New Mexico toward the foothills, and northern slope of the 

 Davis (Apache or Limpia) Mountains, between the San Martin Springs and 

 Van Horn. 



This southern extension of the G-uadaloupe Mountains connecting with the 

 Davis Mountains extends through the Paisano and Mount Ord range to the 

 Sierra St. Jago (Sa. Contrario), which runs down to the Rio Grande, forming 

 the divide between the Pecos (Rio Puerco) and Rio Grande above the mouth 

 of the Maravillas Creek. 



We find on the eastern slope of this divide not only more surface water in 

 the shape of springs and creeks holding water all the year through, but also 

 more favorable artesian conditions. 



The two main forks of the Black River (Rio Azul) originate from numer- 



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