FOOT HILL SECTION. 373 



Measure and Permo-Carboniferous series, having the same strike. A com- 

 pact, gray, siliceous limestone, which is remarkably impure, from near the 

 base of this series, obtained from the summit of the highest peak of the 

 ridge, analysed by Mr. B. E. Brewster, gave the following: 



Silica. - . 54.198 



Alumina 8.814 



Ferric oxide - 2.583 



Lime - . 16.003 



Magnesia 1 3.224 



Carbonic acid 12.641 



Water . . . . , 1.988 



99.451 



From near the head of Evans Canon on this ridge, arid, therefore, not 

 very far from the base of the formation, since the Weber Quartzite fonns the 

 western slopes toward Big. Cottonwood Canon, were obtained a BakeveUia 

 and Eumicrotis, showing that here, as in the foot-hill section, the Permo- 

 Carboniferous fauna had a comparatively wide range. 



About 3 miles north of Clayton's Peak, the limestones bend to the 

 eastward, and the main mass of hills surrounding the Clayton Peak granite 

 body is composed of the Weber Quartzite, here an iron-stained, much-meta- 

 morphosed rock, in which the stratification-lines have become very indis- 

 tinct; the general strike is, however, east and west. In these quartzites, a 

 number of valuable ore-deposits have been discovered, differing only from 

 those of the limestones of Little Cottonwood in their chemical composition, in 

 such a manner as might be expected from the difference of the enclosing rock. 

 To the east of Clayton's Peak, the quartzites disappear beneath the trachytes 

 of the Provo Valley, as has been already seen; their extension to the 

 eastward points unmistakably to the influence of the Uinta upheaval; the 

 several dikes of porphyry coming naturally in this line have already been 

 mentioned. On the north, the Carboniferous limestones can be traced along 

 the foot-hills bordering Parley's Park, striking eastward, until they also are 

 lost under the trachyte body, while in the low hills of the middle of the 



