192 KEMP'S ORE DEPOSITS. 



larly distributed, although possibly connected with fissures. The 

 structural relations with Example 23 may again be referred to. 

 The neighboring slates and granite contain gold and silver veins, 

 which are taken up later on. Several small smelters have been 

 erected in the region, and have been intermittently operated. 

 The country is really in the northern end of the Great Basin. 1 



2.08.21. Example 33. Wickes, Jefferson County, Mont. Fis- 

 sure veins near the contact of granite and liparite, but cutting 

 both rocks and carrying in a gangue of quartz the ores, galena, 

 zincblende, copper and iron pyrites, and mispickel. The liparite 

 is said by Lindgren to be Cretaceous or Tertiary. Wickes is just 

 south of Helena, and was one of the first places in the West to 

 establish successful concentration. There are two companies, the 

 Helena and the Gregory, both large producers. 



/ 2.08.22. Example 34. Coeur d'Alene, Idaho. Galena and 

 very subordinate alteration products, in a mineralized zone having 

 a well-marked quartzite footwall and an impregnated, brecciated 

 hanging of the same rock. The ore is in large chutes, which fill 

 innumerable small fractures in the rock. The mines are in Ward- 

 ner Canon, in the Bitter Boot Mountains, northern Idaho. The 

 rocks are quartzite and thin beds of schists, much folded along 

 east and west axes. In this way they became faulted and shat- 

 tered, and in the principal mineral belt afforded an opportunity for 

 the ore to deposit. The gangue is siderite. The mines are ex- 

 tremely productive and are the chief sources of ore supply for 

 lead smelters in Montana and on the Pacific coast. 2 



THE REGION OF THE GREAT BASIN. 



UTAH. 



2.08.23. Example 35. Bingham and Big and Little Cotton- 

 wood Canons, Utah. Bed veins, often of great size, containing 

 oxidized lead-silver ores above and galena and pyrite below the 

 water level, in Carboniferous limestones, or underlying quartzite, 

 or on the contact between the two. The mines are situated in the 

 Oquirrh and Wasatch Mountains, southwest and southeast of Salt 

 Lake City, in caflons well up toward the summits. The region is 



1 G. F. Becker, Tenth Census, Vol. XIII., p. 55. Engineering and 

 Mining Journal, July 2, 1887, p. 2. Rep. Director of the Mint, 1882, p. 198. 



2 J. E. Clayton, "The Cceur d'Alene Silver-lead Mines," Engineering 

 and Mining Journal, Feb. 11, 1888, p. 108. 



