556 DESCEIPTIVE GEOLOGY. 



brian beds are drawn as forming- a part of the anticlinal fold, but covered 

 by the great arch of Ogden Quartzite. 



This anticlinal axis, continuing southward, trends diagonally across 

 the range at a strike of about south 25° east. The easterly-dipping 

 limestones of the anticlinal, 4 miles north of Pifion Pass, are covered 

 by the body of rhyolite already mentioned, but on the west side of the 

 anticlinal, however, they dip uniformly to the southwest for about 2 miles, 

 when they pass under the synclinal axis, and rise again to the west, having 

 an easterly dip, and exposing the Ogden Quartzite along the west base of 

 the range. In the basin of this synclinal, the Sub-Carboniferous and Lower 

 Coal-Measure formations have been introduced upon the geological map. 

 It should, however, be distinctly stated that no palseontological evidence 

 for such an assignment was obtained, but it has been made for the same rea- 

 son as already given for the great thickness of beds in the region of Eaven's 

 Nest Peak. Near Mineral Hill, on the west base of the range, the Ute- 

 Pogonip limestone comes in below the Ogden Quartzite, extending south- 

 ward for about 4 miles in low broken hills, until concealed beneath great 

 flows of basalt. It forms thci narrow entrance to Cave Canon, where it 

 appears in somewhat higher hills as a hard siliceous blue limestone, with a 

 rough irregular fracture, and dipping under the overlying quartzite. The 

 Ogden Quartzite is seen in low hills of exceedingly hard flinty rock of 

 bluish and reddish tints and a vitreous lustre. Above the quartzite occurs 

 the Devonian limestone, reaching to the summit of Fossil Pass, and form- 

 ing the entire eastern slope. In color and texture, it resembles the lower 

 members of the Wahsatch limestone already described, many of the beds 

 possessing the characteristic buff color. The beds are slightly arenaceous, 

 the siliceous grains being usually very fine, while certain layers are more 

 or less dolomitic in composition. Under the microscope, the quartz-grains 

 show frequent liquid-inclusions. The beds trend diagonally across the 

 range, striking north 20° to 25° west, and dipping 28° to 30° to the east- 

 ward. At Pine Nut Pass, 14 miles to the southward and near the southern 

 end of the map, the structure is much the same, a simple monoclinal ridge 

 dipping eastward; the section, however, exposing only the Ogden Quartzite 



