446 MINING INDUSTRY. 



at a steep angle, and having a north and south strike. They evidently be- 

 long to an earlier formation than any of the Carboniferous limestones of this 

 region, but their connection w^ith strata of well-determined age has not been 

 traced ; no fossil remains have as yet been discovered in them, but they resem- 

 ble in lithological character the quartzites of the Uintah Mountains in Utah. 

 The granite forms the eastern foot-hills of the ridge, extending for about half 

 a mile up Egan Canon; it seems to extend further into the hills to the south, 

 and only to form the extreme foot-hills to the north; it is succeeded above by 

 quartzite, which forms steep, rugged cliffs, rising precipitously a thousand feet 

 or more on either side of the canon. The granite, at the mouth of the canon, 

 is much decomposed on the surface, and stained with iron oxide, while higher 

 up it is more compact, and contains a large proportion of quartz. There seems 

 to be a regular transition from granite into quartzite, the intervening rock 

 being composed of rounded grains of limpid quartz, in a green, feldspathic 

 paste; the quartzite itself, which is the predominating rock in the canon, re- 

 tains this structure in a measure where the feldspar has disappeared, and al- 

 most resembles an eruptive rock ; it has a massive structure, in which the 

 bedding is still visible, however. 



The upper part of the canon is in slates, which succeed the quartzite and 

 alternate with it; the slaty structure is generally very regular, the laminae 

 being about half an inch thick; their cleavage planes seem to conform to the 

 line of stratification. The predominating slates are of greenish and purplish 

 colors; the former seem to be a fine-grained mica-schist, while the latter are 

 frequently nothing more than quartzite, with a slaty structure ; these have 

 frequently rounded grains of limpid quartz, which give them the appearance 

 of a conglomerate. On the very edge of the upper valley is a small outcrop, 

 about 30 feet thick, of finely laminated, argillaceous slates, which present very 

 beautiful dendritic markings on their surface. These slates split easily into 

 very thin slabs, which are tough and somewhat flexible, and apparently well 

 adapted for roofing slates. 



Mineral Deposits. — The first discoveries in this district were of gold, 

 whence it was called Gold Caiion ; but no great amount of gold having been 

 produced, it is better known as Egan Canon, a name derived from that of one 

 of the first explorers of this region, who fixed the present location of the stage 



