TUCUBITS MOUNTAINS. 525 



the upper end of the canon is an outcrop of about 500 feet of calcareous 

 shales, having- a purplish color on their weathered surface, overlaid by drab 

 limestones, which, in turn, are overlaid by some blue siliceous limestones, 

 carrying white seams of calcite containino- crystals of pyrites. 



In the hills to the eastward, beyond the upper end of the canon, as has 

 already been seen, only quartzites are observed, which represent the Weber 

 Quartzite. The limestones extend much farther eastward at the immediate 

 line of the canon than they do either to the north or the south. In the low, 

 rather broken hills which form the continuation of the range to the south of 

 Emigrant Canon, distinct outcrops of compact white quartzite are found 

 along the eastern slopes, dipping about 25° to the eastward and striking 

 somewhat to the east of north. In general, but few exposures are found in 

 these hills, but the surface is largely covered with debris of the peculiar 

 dark-reddish quartzitic sandstone already observed in the Fountain Head 

 Hills. 



Directly south of the Hot Springs is a bare limestone hill, showing about 

 600 feet in thickness, of earthy blue limestones, plentifully seamed with 

 ^ hite calcite, somewhat arenaceous in the upper part, and the beds generally 

 from 15 to 20 feet in thickness. This is underlaid by several hundred feet 

 of darker-colored, sometimes black, limestones, which, in the lower part, 

 are very siliceous. These beds dip about 20° to the southeast. No fossils 

 were obtained from this outcrop of limestones. To the west of this hill, in 

 a little ravine running northwest, just under the base of Tulasco Peak, was 

 found exposed a series of thin-bedded limestones, from which were obtained 

 a number of Coal-Measure fossils, whose aspect indicates a much higher 

 horizon than the apparent position of the beds, which otherwise would have 

 been supposed to be lower than the heavy-bedded limestones just mentioned. 

 The bottom of the ravine is in dark-reddish limy shales. The lowest out- 

 crop shown is 50 feet of white quartzite, overlaid by 100 feet of gray 

 limestone with siliceous seams, above which 10 feet of a bluish-gray lime- 

 stone carrying FusuUna, overlaid again by '60 feet of gray limestone with 

 cherty seams, above which 50 feet of shaly limestone carrying corals, 

 while on the hills above are, though not in direct contact, apparently con- 

 formable beds of the quartzitic sandstones. These beds all dip 35° to the 



