LAKESIDE MOUNTAINS. 465 



siliceous shales, metamorphosed and blackened on the surface, in which are 

 some indistinct impressions of encrinites and corals. On the western slopes, 

 north of the pass, is a body of dark-blue limestone traversed by small veins 

 of white calcite, also containing corals, which dips 85° to the eastward. 

 To the east of the limestones, and overlying them, are reddish quartzites, 

 whose structure, as well as could bQ ascertained from the few exposures to 

 be seen under the accumulations of surface debris, is that of a synclinal 

 descending toward the north. These have been referred to the Weber 

 Quartzite group; the main body of the range being evidently in the Wah- 

 satch limestone. 



Lakeside Mountains. — A similar low ridge of hills, en ecJwlon with the 

 Cedar Mountains, lying along the western shores of Salt Lake, is known as the 

 Lakeside Mountains. Its southern foot-hills are formed of similar quartzites, 

 resting on strata of dark-blue limestone, also carrying crinoid remains, having 

 a Coal-Measure aspect, which form the southern peak of the range, with a 

 strike of northeast and a dip of 45 ° to the southeast. These limestones appar- 

 ently form an .anticlinal to the north, and are overlaid again by the quartzites 

 at the low pass in the middle of the ridge. The northern portion of these hills, 

 as far as could be learned by the isolated observations of our parties employed 

 upon the survey of the lake, are composed of the same heavy dark lime- 

 stones, with occasional lighter siliceous beds, in broken, confused masses, 

 and have been referred to the Lower Coal-Measure group. The island 

 called Strong's Knob, which forms the northern continuation of this ridge, 

 shows to the eastward almost perpendicular cliffs, several hundred feet in 

 height, of dark-blue and black limestones, capped by a grayish limestone 

 bed, containing corals, among which the following have been determined : 



Zaphrentis Stanshuryi. 

 Zaphrentis multilamella. 



The same black and gray limestones are observed in Grunnlson's Island, 

 which is in the same line of elevation, and in Dolphin Island, opposite the 

 Terrace Mountains. 



The desert ridge to the west of the Lakeside Hills is but little known 

 by actual observation. Its northern point shows similar limestone beds to 

 30 D G 



