CQUIEBH MOUNTAINS. 447 



Spirifer striatus, 



Spirifer setiger, 



Spirifer Leidyi, 



AtJiyris subquadrata, 

 which are regarded as Sub-Carboniferous. 



To the south of the mouth of East Canon, the strike of the beds curves 

 round to the east of south, and, at Lewiston Caijon, is ah-eady nearly east 

 and west, parallel with the canon. Lion Hill, as the ridge between Lewis- 

 ton and East Caflons is called, is a flat-topped ridge, consisting of a half- 

 dome of limestone strata, cut off on the north by the fault of East Canon, 

 and sloping away with an ever-increasing dip east, south, and west. These 

 beds are, toward the base, composed of dark, compact, fine-grained, more 

 or less siliceous limestones, with some interstratified beds of shales and 

 seams of black cherty material. On the flanks, toward Lewiston Canon, 

 there are found belts of a comparatively pure bluish limestone, which 

 abound in remains of Spirifers, among which were recognized Spirifer opi?nus, 

 the most abundant single species perhaps in this range. Between Lewiston 

 and the southern point of the mountains, the beds of the Wahsatch lime- 

 stone dip gently to the south and west, rising slightly to the eastward, until, 

 in a line with the main crest of the ridge, they sink down again, passing 

 under the shallow synclinal of Pole Canon. 



The section exposed in East Canon would be somewhat as follows : 

 Passing up through the steeply-dipping beds at the mouth for a distance 

 of nearly a mile, the inclination of the beds gradually decreases, until, at 

 Ophir City, they are on an east and west line, nearly horizontal, but have 

 a slight inclination to the north and south. The canon-walls are entirely 

 in the limestones, the line of fault which has brought up the quartzite being 

 to the north of the canon. Above Ophir City, the beds are almost horizontal 

 for some distance, and then slope ofi" gradually to the east, the dip becoming 

 steeper as one ascends the canon until it reaches 45°. At the forks of the 

 canon, the limestones have a shaly appearance, owing to the frequence of 

 thin interstratified seams of black chert. Above the forks, the dip shallows 

 again, and near the head assumes a westerly inclination, forming a shallow 

 synclinal, which can be traced to the south, following a line just west of 



