OQUIRRH MOUNTAINS. 449 



At the mouth of North Canon, the quartzite beds of the Weber group 

 are found striking northwest and dipping to the eastward; their contact-hne 

 with the trachyte body of the Traverse Mountains following approximately 

 the line of the road from Rose Canon to Cedar Fort. 



Northward from Dry Canon, on the western side of the range, the anti- 

 clinal fold gradually sinks under the plain, and to the north of Soldier Caiion 

 are found the lower beds of the Weber Quartzite, having a northwest strike, 

 and dipping to the north and east. There seems to be here an insensible 

 gradation from the beds of the Wahsatch limestone, which are intercalated 

 with quartzite beds, into the lower beds of the Weber Quartzite, which con- 

 tain interstratified beds of limestone. 



In the quartzites on the foot-hills, between Stockton and Tooelle, is 

 found an interesting occurrence of granite-porphyry, of which fragments 

 are also found in the float coming down from Lewiston Canon. It is a 

 coarsely crystalline, grayish rock, containing large crystals of orthoclase, 

 up to three-quarters of an inch in length, in a semi-crystalline groundmass, 

 composed of quartz, feldspar, hornblende, and black biotite. It is remark- 

 able for the distinct crystallization and fresh, unaltered condition of its con- 

 stituent members; both hornblendes and micas show very sharply-defined 

 hexagonal outlines, while the orthoclase is clear and translucent, having a 

 delicate rose hue. The rock contains besides considerable titanite, which 

 may be seen in comparatively large well-defined crystals within the larger 

 crystals of orthoclase. A few of the orthoclases show a tendency to a zonal 

 alteration. Besides titanite, these crystals contain also small hexagonal 

 flakes of mica, and occasional crystals of hornblende. 



The beds of the Weber Quartzite, as seen along the foot-hills from 

 Stockton to Tooelle, are mairdy composed of a close, somewhat vitreous 

 rock, stained by oxide of iron, and breaking easily into small fragments, so 

 that the slopes are so covered with debris as to conceal the structure-lines. 

 At the mouth of Tooelle Canon, the quartzites are seen to have a strike 

 nearly north and south, and to dip to the westward; the lower 1,000 feet 

 being composed of a white compact quartzite. At the forks of Tooelle 

 Canon are exposed heavy limestone beds, lying conformably under these 

 quartzites, which correspond to the upper members of the Lower Coal- 

 29 D G 



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