250 GEOLOGICAL SURVEY OF THE TEREITOEIES. 



series of limestone shales. These beds on top of the bluff dip toward 

 the northeast at an angle of 60° to Go'^. Following the ridge to the north 

 we find that a red feldspathic granite makes its appearance, and on a 

 high rounded hill on the east side of the amphitheater at the head of 

 the creek, resting on the granite, is a bed of white quartzite, above 

 which are bluish and yellow limestones. These beds, I take it, are 

 Silurian. At the southwest side of the hill the dip is toward the south- 

 west. This gradually changes to the west, and finally to the northwest 

 as we go toward the northern end of the hill, where the angle of inclina- 

 tion is 25°. Between these beds and those referred to above as appear- 

 ing in the cliffs farther down the creek, there seems to be a break. In 

 the amphitheater are beds of blue limestone with shales, all dipping 

 toward the southwest ; but when we ascend the ridge on the northern 

 side we find limestones, black shales, and sandstones, followed by thick 

 beds of limestone, all dipping to the northeast. When w^e ascend 

 Italian Mountain the confusion of these beds is explained. The mount- 

 ain is named from the colors it shows at a distance, red, white, and 

 green, the Italian national colors. The white is due to the granite, of 

 which the peak is mainly composed ; the red is seen on the weathered 

 surface of included beds of quartzite, and the green is seen in the 

 grassy slopes on the eastern side of the mountain. Its elevation is 

 13,255 feet. 



The i^eak is made up in part of a light- gray granite, which I consider 

 to be eruption, and rusty quartzites very much metamorphosed. These 

 quartzites in places stand on end, and in others dip southwest and north- 

 east, at angles from 80° to 85°. Between some of the beds are long 

 narrow seams of the granite. This is beautifully shown in the accom- 

 panying illustration made by Mr. Holmes, Fig. 



This shows, also, how the quartzite has been broken n-p by the gran- 

 ite. The illustration shows the* northern face of the peak. On the west 

 side there is a fault of about 400 feet in the quartzite. This fault ex- 

 tends to the northwest, and I shall refer to it again. Extending from 

 the peak toward the southeast is a line of eruptive granite gradually 

 thinning out. Close to Italian Mountain is a high point at the com- 

 mencement of a ridge, which forms the western side of the amphithea- 

 ter heading Taylor Creek. Italian is the most eastern high peak in the 

 Elk Mountains. The name Elk Mountains is applied to the mass of 

 mountains between the Gunnison Eiver and the waters of the Eoaring 

 Fork of Grand Eiver. The trend- of the range, at first, is almost at 

 right angles to the trend of the Sawatch range. Afterward, however, it 

 turns to the northwest. The nucleus of the range is composed of erup- 

 tive granite, of which that on Italian Mountain is a part. The general 

 trend of this granite, which shows itself in three island-like patches, 

 entirely isolated from each other, is northwest and southeast. This is 

 also indicated by the courses of the principal streams. The course of 

 Eoaring Fork and its branches is toward the northwest, while East 

 Eiver flows to the southeast, its course being parallel to that of Eoar- 

 ing Fork, although it flows in exactly the opposite direction. 



To the north of Italian Peak, between it and the divide between the 

 Gunnison and Eoaring Fork, there are remnants of the sedimentary beds. 

 To the west we have a grand view from the summit. The island of erup- 

 tion is distinctly shown, the white or light-gray color of the granite be- 

 ing contrasted with the dark colors of the older stratified rocks, above 

 which are the bright-red sandstones of Triassic age, and resting on them, 

 in a few isolated places, patches of lighter-colored beds that are of 

 Jurassic and Cretaceous age. The sedimentary beds are beautifully 



