150 



ECONOMIC GEOLOGY 



agencies of the weather and meteoric water. Beneath this there 

 is a zone of unaltered sulphides which furnish the main ores of the 

 camp. 



According to W. H. Weed, hot alkaline solutions leached the 

 metals from the granite at considerable depths and wherever the 

 fissures were open they were filled with ore and where the fissures 



Rd nodular halea with ero*f- 

 bedded. buff. Uwny, and red 

 landllonea. A few t)t*l <jf irn- 



Biiff, mwny and red gan'ditonea 

 and dark-red halea, with an 

 rcnlonl thin bod ,if impure 





Chiefly light-gray, compact llmv 



Contain* abundant Cu-wlli 

 Cat by granite-porphyry. 



!, wl-rio ff li>:tit-tfm: 



Thin-bedded. Impure, cheny 

 limestones. Cut by granite- 



Serlclte-flchina. Cut by granite 

 and granite-porphyry. 



a formation. 1,800 fen 



\>-:\ by urw-Crey 



Abilgollmettone, 770 feet. 



ile. -130 feet. 

 >nfbrmity. 



GENERALIZED COLUMNAR SECTION OF THE ROCKS OF THE BISBEE QUADRANGLE. 



FIG. 89. Geological section at Bisbee, Arizona. After Ransome. (By 

 permission of the Macmillan Company, from Ries' Economic Geology.) 



were narrow their walls were replaced, so that the vein matter 

 shades off into the country rock. 



Arizona. In Arizona, the southern division of the Cordilleran 

 region, there are five important copper districts. The Bisbee; 

 Clifton-Morenci; Globe; Jerome, and Mineral Creek. (See Figs. 

 87 and 88.) 



(1) The Bisbee district is situated on the eastern slope of 

 the Mule Mountains and is only a short distance north of the 

 international boundary with Mexico. The ores are found in 



