16 



GEOLOGICAL SURVEY OF THE TEREITOEIES. 



satch group about the sources of Ogden Creek ; then the low Jurassic 

 ridges, inclining 10° to 15°, gradually passing down into sandstones, 

 quartziteSjthen arenaceouslimestones,changing gradually to pure massive 

 limestones of Carboniferous age. As we pass down the canon from Ogden 

 Yalley, or, as it is named on our maps, Ogden Hole, Ave observe the 

 Carboniferous limestones rising like high, nearly vertical, walls on either 

 side, at first inclining about 8°, within ten miles dipping 20° to 30°, and 

 1,500 to 2,000 feet in thickness. In these limestones are some remarkable 

 illustrations of the folding of the strata, (Fig. 2.) In one locality there is a 



Fig. 2. 



WEDGE OP LIMESTONE, OGDEN CANON, 



group of strata, perfectly cross-sectioned by the stream, 300 feet long 

 and 200 feet high at the thickest end, in the shape of a huge wedge. 

 Underneath these limestones comes a yellowish-gray quartzite, which 

 forms a portion of a ridge inclining 20° to 25°. A small gulch inter- 

 venes, and the next ridge runs up like a cone with a dip northeast 55°, 

 and the strata are brought out remarkably clear, with a height of 1,500 

 to 2,000 feet ; beneath the quartzite is another bed of brittle limestone 

 of better quality than the other, of a bluish-gray color, passing down 

 into a steel-gray. The coarse portion is quite slaty. It is this bed that 

 furnishes the material for burning into lime. These limestones incline 

 30°, and are about 1,500 feet in thickness. The next bed is composed 



