ALPHA AND FT8ILINA PEAKS. 159 



fossils, the best locality noticed being on tin- .summit of the ridg-e about 

 one-third of a mile south uf the peak and 150 feet below the highest point. 

 Ten species were obtained here, the list being given on page 91. The two 

 most interesting species are Spirifcra trifjonalis and Cniiiarophorui voopercnais, 

 the latter identical with the Missouri form. Both of them, as pointed out 

 by Mr. Walcott, are characteristic of the loAver Carbonifei'ous in the ]\Iis- 

 sissippi Valley. It is these two species that serve to correlate the low lime- 

 stone ridges south of Newark Momitain with the base of the Lower Coal- 

 measures. 



Immediately northwest of the crest of the ridge the strata dip easterly, 

 and at about the same distance below the summit, as observed on the 

 opposite side of the peak, the quartzites come in conformably beneath the 

 limestones, dipping ea.sterly into the ridge. No consideral)le tliicknesses of 

 quartzites are exposed, as they are abruptly cut off by the profound Alpha 

 Peak fault, which brings the Upper Coal-measure limestones unconform- 

 ably against them. Following the quartzites southward, they are seen to 

 be much broken up and dislocated, and southwest of the peak again dip 

 westerly, with an angle of about 15°, a dip which the}' maintain as far 

 south as Bold Bluff, where they terminate abruptK- against the Newark 

 fault. By reference to atlas sheet vi the position of the (juartzites mav be 

 readilv made out, completely encircling Diamond Peak on all sides. 



Newark Fauit.-Tliis liuc of faulting, starting in at Bold Bluff', trends 

 southward along the abru})t west wall of Hayes Canyon, following the 

 contact between the two dissimilar formations — the gray Lower Coal- 

 measures and the black White Pine shale. It is easily traceable for nearly 

 3 miles. At the southern end it gradually ti-ends off to the southeast, com- 

 l)letelv cutting off the shales, as well as the Diamond Peak (piartzite, and 

 at the mouth of Hayes Canyon brings the Lower Coal-measures directly 

 against the Nevada limestone of Newai'k Mountain. 



Region of Alpha and Fusiiina Peaks.— The Lower Coal-measure limestone 

 overlying the Diamond Peak quartzite foi'ms an unbroken nari'ow ridge, 

 extending southward for over 9 miles, and falling away gradually until 

 it passes beneath the Quaternary of the valley. This ridge presents great 

 simplicity of structure and monotony of appearance, the beds exhibit- 



