THE PENOKIE RANGE. 



445 



may with confidence pronounce it to be a continuous bed from the meridian west- 

 ward to Lac des Anglais. Its thickness, richness, and value vary very much ; but 

 we found it more or less developed whenever we crossed the range, and could get a 

 view of the rock. 



The geological relations of the iron-bearing strata are exhibited in the two following 

 sections, the first taken near the trail that passes over the Pewabic Range, between 

 the Forks of the Tyler branch of Bad River ; the second, south of Lac des Anglais. 



d, d. Drift. d, d. Drift. 



c. Slaty magnetic iron, fifty feet c. Iron-bed, twenty-five to sixty feet. 



b. Compact and slaty quartz. b. Quartz, thirty feet. 



a. Talcose slate. a. Hornblende and slaty quartz. 



On the Pewabic Range, the strike of the beds is east by north ; the dip north 

 by west, 80° to 85°. The beds of quartz are of great thickness, — two hundred to 

 two hundred and fifty feet. Near the junction of the quartz and talcose slate, the 

 latter assumes the aspect of novaculite. The iron-bed is schistose in its structure, 

 and is composed of magnetic oxide, sometimes alternating with beds of quartz. 

 The total thickness of the talcose slate is not seen ; it must be very thick, and is 

 traversed by numerous veins of quartz. Its dip and strike are variable. 



The bed of magnetic iron ore south of Lac des Anglais is of extraordinary thick- 

 ness, — twenty-five to sixty feet. The dip here is northeasterly, and the layers 

 variable in thickness that alternate with quartz, which latter repose upon horn- 

 blendic slate, running downwards into talcose slate. Here, as well as on the 

 Pewabic Range, the dip and strike of the beds are variable. 



The metamorphic strata are very much disturbed throughout this range ; but 

 agree in having the mural faces of the uplifts to the south and southeast, and the 

 dip northerly and northwesterly at various angles of from 5° to 60°. The effect 

 of this irregular action is to make detached ridges and crests, sometimes two, three, 

 and five miles long, thrown up at different elevations and inclinations. 



Sometimes the iron stratum is composed of laminae of quartz and magnetic oxide, 

 alternating, as at the crossing of the trail between the forks of the Tyler Branch of 

 Bad River; also south of Lac des Anglais. 



The proportion of iron and quartz is very variable, but the separation of them 

 by mechanical means would in general not be difficult. The bands of ore vary 

 from mere thin laminse to a thickness of twelve and even eighteen inches, presenting 

 sometimes a black surface, contrasting with the white and gray colour of the quartz, 

 and sometimes a bright metallic gray colour. The thickness of the metalliferous 

 portion varies in the extreme from five and ten feet up to fifty and seventy feet ; 

 and at the passage of the main portion of Bad River through the range reaches two 

 hundred and fifty feet. These exposed faces frequently extend beneath the surface, 

 Avhere, of course, no estimate can be formed of their entire thickness. 



There are many places in the mountain, west of Bad River, which present more 



