504 DESCRIPTIVE GEOLOGY. 



The qiiartzite mass, already referred to, nortli of Middle Pass, like 

 the granite, stretches across tlie entire width of the rang-e. It is distinctly 

 bedded in heavy broad masses, striking north 34° east, with a dip to the 

 southeast. This quartzite is mainly white, with bands showing both bluish 

 and grayish tints, and also can-ies beds of almost black quartzite. It 

 appears to be made up of both large and small quartz -grains, metamor- 

 phosed and compressed into a dense compact rock. Many of the large 

 grains are white and clear, while others appear to be flattened into thin flakes 

 and sheets of quartz, with a decidedly schistose structure. Under the micro- 

 scope may be seen minute flakes of white silvery mica, sometimes aggregated 

 in layers; in the quartz are numerous fluid-inclusions. A small percentage 

 of iron frequently colors the rock shades of brown and red. 



South of Middle Pass, for a long distance, quartzite forms the main 

 ridge, with the limestone overlying upon the flanks. In the region of Pine 

 Mountain, where best observed, the limestone, of a light bluish-gray color, 

 occurs dipping steeply to the westward. Near the summit, the following 

 Coal-Measure species were collected : 



Spirifer opimus. 

 Atliyris suhtilita: 



At Lookout Mountain, the culminating point of the range, which at- 

 tains an altitude of 9,645 feet above sea-level, occurs an immense develop- 

 ment of limestone. There are represented here between 3,000 and 4,000 feet 

 of conformable strata, heavily-bedded, compact, blue limestone, with escarp- 

 ments and walls varying from 30 to 100 feet in height. From Dondon 

 Pass to the peak, the strata dip to the southward at an angle of 9°; along 

 the main ridge of the peak the dip is 13°, and on the summit 9°. From 

 the top of the mountain southward, there is a tendency to an anticlinal axis, 

 and the beds which form the summit due west from Lookout Mountain 

 dip sharply to the southwest. 



The outlines of the limestone body to the northward and its exact rela- 

 tions to the quartzite formation were not worked out. The limestone has, 

 however, been referred to the Lower Coal-Measure series of the Wahsatch 

 limestone, partly on account of its great thickness, partly from its litho- 



