TOANO GROUP. 517 



It is a dark-gray, almost black, pearlitic mass, containing crystals of sauidin 

 and quartz, with a large development of reddish sphserulitic grains, which, 

 when broken, are seen to be made up of concentric layers of sphserulitic 

 material of a dull resinous lustre, often enclosing a nucleus of glass, quartz, 

 and feldspar. 



To AND Group. — To the west of the Goose Creek Hills is a broad valley, 

 narrowing rapidly to the northward, called Desert Gap, through which runs 

 Passage Creek, a stream carrying the drainage of Thousand Spring Valley 

 and the mountains to the north out into the desert country. To the west 

 of the gap, the Toano Group forms an irregular mass of hills, a continua- 

 tion northward of the Gosi-Ute Range, and separated from it by a low 

 broad pass, known as Toano Pass, through which the railroad runs. The 

 Toano Pass cuts the range at a point where the axis of upheaval has suf- 

 fered an abrupt curve. That part of the range south of the pass has a 

 strike nearly true north and south, which it maintains up to the pass, north 

 of which it forms roughly a semicircular ridge, the strike of the beds fol- 

 lowing the curve of the ridge. 



Between this pass and Ives' Pass, 5 or 6 miles to the northward, the 

 hills form a somewhat isolated group, showing an interesting structure, with 

 Fairview Peak both topographically and geologically the central point. 

 On the northeast side of this ridge, the beds strike north 5° to 10° east, at 

 Fairview Peak north 30° east; while on the west side they strike north- 

 west. The beds form an anticlinal fold, the axis occurring in the Weber 

 Quartzite along the south slope of the hills, conformably over which lie 

 heavy beds of blue and gray limestone. The high hills north of Toano are 

 formed for the first 1,200 or 1,500 feet of Weber Quartzite, and then 800 or 

 900 feet of limestone, the latter forming the summit of the ridge, and the 

 north side of the anticlinal axis. Fragments of limestone, which represent 

 the southern half of the anticlinal fold, are found along the extreme foot- 

 hills of Toano Pass, with a steep dip, reaching in places 60°. It is evident 

 that both sides of the anticlinal have suffered a fault, and that the southern 

 member, including both quartzite and limestone, has been depressed several 

 hundred feet. On the opposite side, the Coal-Measure limestone also shows 



