78 



TiOa 0-90 0-88 



P2O5 0-46 0-51 



MnO o-o8 0-09 



SrO 0-09 o-o6 



BaO 0-24 



99-36 99-88 



I. Class dosalane, order germanare, rang andase, 

 subrang shoshonose. 



II. Class dosalane, order germanare, rang monzonase, 

 subrang monzonose. 



Glacial and Recent. 



The area about Phoenix is free from any thick or con- 

 tinuous mantle of drift. Cuttings in the valley of Twin 

 creek show rudely stratified sands, clays and gravels. The 

 surrounding ridges are glaciated to their crests, the striae 

 having a direction of S. 26° E. 



ORE DEPOSITS. 



The copper deposits occur at intervals along the edges 

 of the zones of contact metamorphism and also at the base 

 of the zone or in some non-outcropping intermediate 

 position. 



The zone in which the principal deposits occur is 

 horseshoe-shaped. The west limb is 3,200 feet (975 m.) 

 long and 1,000 feet (304 m.) wide, while the east limb is 

 2,250 feet (686 m.) long and from 350 to 1,000 feet (107 

 to 304 m.) wide. The thickness varies from one foot 

 (30 cm.) or so to 350 (106 m.). The floor is jasperoid or in 

 places the siliceous rocks of the Knob Hill group. 



Knob Hill- Ironsides mine — The ore body of the above 

 mine owned by the Granby Consolidated, is the largest 

 and most typical of the camp. The ore body is com- 

 posite in character and consists of two lenses which 

 coalesce about their central portions. Along the outcrop 

 these appear as distinct ore bodies separated by a 

 varying thickness of the lime-silicate gangue rock (see 

 section). The western lens is at least 2,500 feet 

 (762 m.) long, from 370 to over 900 feet (113 



