COPPER ORES IN THIS COUNTRY 263 



or the present Clifton mining district in Arizona, and work 

 was bej^^im in 1894. The building of the Southern Pacific 

 and Atlantic Pacific through southern Arizona developed 

 the mines and exerted a marked influence on the copper 

 industry. The principal districts are the Warren, Globe, 

 and Black range. 



From an interesting description by Mr. A. F. Wendt, 

 we note that copper in that southwest region may occur, as 

 at the Santa Rita mines, New Mexico, at the contact of lime- 

 stone, and an eruptive rock, such as felsite porphyry, i.e., 

 a rock composed of a paste of feldspar in which are set dis- 

 tinct crystals of feldspar like plums in a pudding. The orig- 

 inal openings bj^ the Mexicans show that they found native 

 copper in the felsite disseminated through it in shots, flakes, 

 leaves, and even in broad, thin masses, 2 feet square. Some- 

 times this copper is altered into a red cuprite, an ore not un- 

 like cinnabar in color, sometimes in fine hairs, resembling 

 red plush velvet. A smelter erected did not find these ores 

 in the felsite very profitable, but at the contact of the felsite 

 and limestone, green carbonates and oxides of copper occurred, 

 which were profit al:»l3^ mined and smelted. 



At the junction of the limestone and the felsite, an enor- 

 mous outcrop of brown hematite or iron oxide occurs. This 

 may be the gossan, cap, or blossom of underlying copper 

 ore. Such brown, rusty gossan is an almosL invariable sur- 

 face outcrop of a copper vein. 



In the Clifton district of Arizona, one of the oldest and 

 largest producers in the southwest, we have a basin surrounded 

 by an almost circular range of mountains. A significant 

 sign to the prospector of the character of the ore contained 

 in this basin is that the water of Chase creek, issuing from 

 it, is so highly charged with solutions of copper that it is 

 undrinkaljle. The copper in this solution is doubtless in 

 the condition of a sulphite popularly known as blue vitriol, 

 and as its composition is sulphuric acid, copper oxide, and 

 water, its unpalatable character can readily be imagined and 

 accounted for. There are springs issuing from a copper 

 lead in Bingham canyon, Utah, so strongly impregnated, 

 that by throwing scrap iron into them a considerable amount 



