OQUIRKH MOUNTAINS. 451 



green fibrous mass, wliich will be found more fully described in Professor 

 Zirkel's Report, Vol. VI, Plate III, fig. 2. 



The mass of the range around Bingham Cailon, and to the south 

 as far as the mouth of North Canon, is occupied by the Weber Quartz- 

 ites. The structure of this portion of the range is very obscure, owing to 

 the broken and metamorphosed nature of the beds and the complicated 

 position of the folds. On the eastern foot-hills of the range, opposite 

 Lewiston Peak, the eastern dip is seen in the limestones of the Lower 

 Coal-Measures as they gradually sink to the southward : the axis of the 

 North Canon fold passes through the low saddle on the spur to the south 

 of the stream, showing that here, as in Tooelle Cailon, the eastern mem- 

 ber of the fold is much the more abrupt. North of the mouth of North 

 Canon, the limestones pass by a gradual transition into the lower quartzites 

 of the Weber group, which are seen striking northwest with a dip to the 

 westward, forming the western end of the Traverse Mountains in contact 

 with the trachyte body, and crossing the mouths of Rose and Butterfield 

 Canons into Bingham Canon, 



At the head of Butterfield and Bingham Canons, they form the main 

 crest of the range. In the latter, the easterly dip shallows near the forks, 

 and steepens again below, while at the extreme mouth of the canon the 

 beds turn up steeply, and dip 60° to the west. The section exposed in 

 Bingham Cailon, therefore, represents in general a synclinal fold, whose 

 eastern member is short and abrupt; the whole series descends toward the 

 north. In the north fork of Bingham Canon, where the bedding of the 

 quartzites is rendered more distinct by occasional interstratified calcareous 

 beds, the observed strike was north 35° east, with a dip 45° to the north- 

 west; while on the spur to the east of this fork, the strata curve around and 

 assume gradually an east and west strike, and dip to the north and east. In 

 Bingham Canon itself, the quartzites are very much metamorphosed, broken, 

 and stained with iron, and rich in silver-bearing minerals. Owing to the 

 irregularity of the folds, it is almost impossible to estimate the thickness of 

 this development of quartzite. It can hardly be less than that found in the 

 Wahsatch Range, however, and seems to be much greater. 



At the head of the south fork of Bingham Canon is a diorite-dike, which 



