WEST HUMBOLDT RANGE. 729 



limestone, and display the underlying quartzitic schists of the interstratified 

 Star Peak series. Local flexures in Buffalo Canon throw the underlying 

 quartzites around to a true north and south strike, which, however, they 

 maintain only for a short distance; the dip in these local cases rising as 

 high as 60° to the eastward. Along Buffalo Peak, the limestone is locally 

 converted into marble, and is then entirely destitute of planes of stratifi- 

 cation. 



From field-notes furnished by Mr. J. D. Hague, the foot-hills south of 

 Sacramento Canon are found to consist of the Star Peak limestone, much 

 broken up and irregularly bedded, having a general strike of north 15° to 

 20° west and dipping southwest. This conforms with observations on the 

 same strike to the northward, and shows the limestone as turned up against 

 the plane of the northwest and southeast fault, which has sundered the two 

 halves of the range. South of this point, on the west side of the Buffalo 

 Peak mass, in the American Mining District, Mr. J. D. Hague also found 

 dark limestone beds dipping 20° to 30° to the east, and striking north 20° 

 west, underlaid by altered argillaceous limestones, passing down into 

 quartzitic beds, which contain the crushed and half-obliterated remains of 

 Nautili. From the limestones of American District were collected the fol- 

 lowing Triassic species : 



Haldbia dubia. 



Trachyceras WJiitneyL 



Ceratites Haidingeri. 



Ammonites, sp.? 



Ammonites, sp.? 



Goniatites {Clydonites) Icevidorsatus. 



Wrapping around the southern extremity of Buffalo Peak occur some 

 rather obscure outcrops of Tertiary strata, mainly consisting of thinly 

 bedded calcareous sands and fine conglomerates, held firmly together by a 

 fine binding material. As they lie turned up at an angle of 25° to 27°, 

 uplifted by the basaltic eruptions, they have been referred to the Miocene 

 age. 



Basalt is the only Tertiary eruptive rock recognized in the northern 

 end of the West Humboldt Range, with the exception of the obscure 



