422 DESCRIPTIVE GEOLOGY. 



formable strata dipping, as already mentioned, about 38° to the west. They 

 are much contorted, and show more or less faulting, so that their thickness 

 cannot be accurately determined. It is, however, not less than 3,800 feet. 

 About the middle of the series, there is an included zone of yellowish- 

 brown sandstone, more or less calcareous, within which are several beds of 

 gray limestone. Its lower portion is sharply defined from the underlying 

 limestones; but, 300 feet above where it passes again into the limestones, it 

 shades off gradually through shaly beds. The general strike of this por- 

 tion of the range is north 28° east. 



Along the extreme eastern foot-hills, on the edge of the Lower Quater- 

 nary plain, which borders the lake-shore, are outcrops of easterly-dipping 

 beds, which evidently show a portion of the eastern half of an anticlinal 

 fold, of which the main mass just spoken of is the western member. This 

 anticlinal fold appears very distinctly in the group of hills about 8 miles 

 south of Promontory Station, of which Benada Peak is the culminating 

 point. Here a distinct northern axis cuts the range, and south of that point 

 the rocks dip to the eastward. Through the pass, about 1^ miles north of 

 Benada Peak, passes a synclinal axis quite parallel to the anticlinal, which 

 lies 1 or IJ miles to the west of it. Here the easterly-dipping members of 

 the western anticlinal and the westerly-dipping parts of the eastern, or second 

 anticlinal, meet. The second anticlinal passes through Benada Peak itself, 

 and, as has been said, to the south of that point, for about 12 miles down 

 the range, the greater part of the limestones dip uniformlj^ to the east, at 

 angles varying from 20° to 40°. At Flat Pock Point, on the west side of 

 the range, are found portions of the western members of this anticlinal fold, 

 dipping at a gentle angle into the lake, and consisting, for the most part, of 

 gray and drab limestones, among which are intercalated bands of yellowish- 

 brown sandstone, similar to that described in the westerly-dipping mass 

 south of Promontory Station. 



From the westerly-dipping limestones, about 5 miles south of Promon- 

 tory Station, near Antelope Springs, were obtained the following fossils: 



Productus Frattenianus, 

 Spirifer opimus, 

 Athyris suhtilita, 

 Streptorliynchus (fragments) ; 



