450 DESCBIPTIVE GEOLOGY. 



Measure limestone, as seen along the main crest, on a line due south from 

 this point. The beds at the bottom of the cailon are massive and somewhat 

 argillaceous limestones, from which were obtained the following Coal- 

 Measure fossils: 



Fenestella. 



JProductus semireticulatus. 

 Productus Prattenianus. 

 Spirifer cameratm. 

 Spir-ifer opimus. 



The limestone beds north of the fork bend in strike somewhat to the 

 east of north with a dip to the northwest, and belong to the northern end of 

 the eastern anticlinal fold, where it, to use the expression of the English 

 geologists, " noses under " the overlying quartzites. The eastern member 

 of the North Canon fold, of which this- is the northern point, has a much 

 steeper dip and is less well defined than the western, and it seems probable 

 that the folding has been accompanied with some faulting which has lifted 

 up the western member ; this would account for the character of the main 

 crest of the range between Tooelle and Connor Peak, whose beds are nearly- 

 horizontal, and resemble in that particular the structure of the ridge of 

 Timpanogos Peak. Passing up the north fork of Tooelle Canon, the lime- 

 stones soon disappear under quartzite beds ; near the head of the canon, 

 already, a bed of yellowish- white quartzite seems to have a western dip, but 

 this may be merely a local displacement. 



On the divide between Tooelle and Bingham Canons, occurs another 

 body of granite-porphyry, somewhat similar to that already described on 

 the western foot-hills. It is a light-green rock, in which the feldspar crys- 

 tals are generally smaller and opaque, whereas, in the rock of the foot-hills, 

 the feldspars are generally fresh and translucent. A few of the large trans- 

 lucent feldspars can be seen in this rock also. Its groundmass contains a 

 much larger proportion of hornblende, which is of a dark-green earthy color, 

 and almost no mica. No titanite w^as detected in this rock. Under the 

 microscope, the hornblendes present remarkable phenomena of alteration, 

 being changed into three distinct' products, magnetite, epidote, and a leek- 



