134 DESCEIPTIVE GEOLOGY. 



approximately with the topographical trend of the range. This change in 

 the direction of the geological axis produces a sharp bend on the eastern 

 side of the range ; the beds dipping in opposite directions toward each other, 

 forming a synclinal fold, narrow near the angle of the bend, but widening 

 to the westward. 



This structure is first indicated by the rocks on the north slope of 

 Davis Peak dipping distinctly to the northwest. Near where the Grand 

 Encampment Creek leaves the mountains, the beds dip a little south of west, 

 and strike west of north. In the higher portion of the range at this point, the 

 prevailing strikes are east and west, while the basin-like depression of En- 

 campment Meadows seems to occupy a synclinal trough, the beds to the 

 south having a prevailing northwest dip, while to the north their inclination 

 is generally southward. 



Northward, the broad axis of the anticlinal passes through the region 

 of Grand Encampment Mountain, with the sides of the fold falling oif to the 

 southwest and northeast at highly-inclined angles. At the bend of Snake 

 Creek, below Camel Peak, the red gneissic beds dip as steeply as 45° to 

 the southwest. In the canon on the spur between the forks of Battle Creek, 

 the rocks are seen dipping 45° a little west of south. To the east of the 

 head of Jack's Creek, the strike is about north and south with a westerly 

 dip, while at the northern end of the range the beds sink suddenly at an 

 angle of 60° to the north, with a strike of east and west. 



In their lithological character, the highly crystalline beds of the Park 

 Eange vary considerably in texture, color, and habit ; but all the promi- 

 nent rock-masses may be classed under granites, micaceous and hornblendic 

 gneisses and schists, and probably interbedded syenites and diorites. They 

 differ in many respects from the beds of the Colorado and Medicine Bow 

 Ranges, although they more closely resemble the former than the latter, and 

 for that reason have been referred to the Laiu-entian. They are character- 

 ized by the presence of much structureless granite of a decided reddish tint, 

 overlaid by gneisses and schists, similar to the series of the Colorado 

 Range, but carrying more hornblende-bearing beds in the upper members. 

 On the other hand, they are wanting in those rocks that are more especially 



