198 GEOLOGICAL SURVEY OF THE TEKRITOEIES. 



^ve saw ilie village of North Oc^don, some four or five miles to the right 

 of our route, at the foot of the uiouutaiu, in an augle of the lower terrace, 

 at the mouth of the pass which afforded communicatiou with Ogden 

 Bole before the construction of the road through the previously impass- 

 able cafiou. The mountain between this pass and the canon has a base 

 of metamorphics, a precipitous face of the lower quartzite, an upper 

 moderate slope of the calcareous shales and lower limestone, and a crest 

 of the upper quartzite. In the portion trending back toward the pass. 

 the shales and limestones descend somewhat, and have been weathered 

 out into an immense amphitheater, reported as being very grand by Dr. 

 Peale, who examined it. 



The hot springs are located immediately at the foot of a high 

 shoulder of the mountain, consisting of the upper terrace, preserved 

 from wear and upheld by a mass of quartzites, shales, and limestones, 

 "which form the continuation of the uppermost of the subordinate folds 

 on the west flank of Ogden Peak. Though the connecting portion is 

 gone, so far as can be seen, yet some portions of these beds are doubt- 

 less in place beneath the plain which stretches past North Ogden to 

 near the mouth of Ogden Canon. The terrace at the hot springs ex- 

 poses both sides of the fold very plainly ; and here we find, as on Ogden 

 Peak, that the eastern side of the fold is much the steepest, and has 

 been pinched out, so as to show but a thin outcrop. ' The portion of the 

 terrace next to the mountain consists of metamorphic rocks, as does 

 also far the larger part of the mountain-face. The rocks are mainly 

 hornblendic gneiss and syenite, with quartz-veins. The crest of the 

 mountain here consists of the second quartzite, and reaches an eleva- 

 tion so nearly identical with that of Ogden Peak that 1 am in doubt 

 which is the higher. 



The hot springs flow from the quartzites of the west side of the fold 

 at the end of the terrace, practically on the same line of crack as those 

 just outside the mouth of Ogden Caiion. 



Jus't beyond the springs, several of the high spurs of the mountain 

 form very prominent pinnacles, being capped with masses of the first 

 quartzite, from above which the overlying calcareous shales, by reason 

 of their softness and the easterly dip, have been readily eroded. This 

 structure, as well as the general bedding before described, can be plainly 

 seen by those who may pass on the cars between Ogden and Corinne. 

 A fine fall leaps over this quartzite in Willow Creek Caiion, opposite 

 Willard City. 



As we pass northward, the mountain bears farther to the east, the 

 axis of upheaval jiasses out under the plain, and the quartzites and 

 limestones decline from high dips to nearly level positions, the second 

 quartzite passing from the very crest to the very bottom of the mount- 

 ain just north of Box Elder Caiion, back of Brigham City, and about 

 twelve miles from the hot spring-s. The high monoclinal dips seen by 

 Dr. Hayden along this caiion in 1871 probably represent the continua- 

 tion of the axis of either the "wedge" or the '^Z" of the upper lime- 

 stones in Ogden Caiion, but show greater disturbance than was there 

 experienced. For about six miles north of Brigham City, the upper 

 quartzite forms the base of the mountain, but then disappears, and the 

 upper limestone alone outcrops, though a thin local bed of quartzite 

 appears about the middle of its section for a short distance. At Mr. 

 Barnard's place, about five miles above Brigham City, I was shown a 

 fragment of galena in calcite, with some green carbonate of copper, 

 from an opening in the limestone about a thoasaud feet up the mount- 



