180 THE CKYSTAL FALLS IRON-BE ARIXG DISTRICT. 



deposits, lias there a great thickness, but its determiiiatiou by actual measuremeut is 

 impossible, on account of the much folded condition of the strata, and for want of cou- 

 uected exposures transverse to the stratification. Estimating its thickness to several 

 thousand feet is surely not far bej'ond the truth. This folded condition of the strata 

 is in many instances an obstacle iu the decision, whether in a given locality we have 

 under observation a descending or an ascending succession of beds. 



If we follow the railroad from Crystal Falls village upward along the bed of 

 Paint River, we find, in the first cut the road makes into rock beds, a series of hard, 

 black slates, transversely intersected in almost vertical positions, and, according to 

 their cleavage planes, dipping in southwest direction. This crosscut is 210 steps long; 

 thence, for the distance of 100 steps, no rock ledges are touched by the roadbed, but 

 oa the left side of the road similar slate rocks are denuded, which apparently represent 

 a continuation of the former succession. From here for eighty steps a cut is made 

 through similar slate rocks, but interlaminated with numerous quartzite seams; 

 further on, the intersection of slates in alternation with quartz seams continues for 

 quite a while, but these slate rocks are more graphitic than the former and readily 

 disintegrate, on exposure, iu-to splintery fragments, as they contain a large proportion 

 of iron pyrites and rustj' ferruginous seams causing the decay. By this time we have 

 reached close to the river below its falls, and find, laid open in its embankments formed 

 by the bluffs thirty feet high, a further conformable series of graphite-schists, 300 feet 

 wide. Beneath the graphite-schists, close to the water level at the foot of the falls, 

 succeeds an ore belt six feet wide at the surface, but widening to fifteen feet, followed 

 into the hillside.' 



Below the ore belt follows au immensely large succession of thinly laminated 

 banded ferruginous quartz-schists of dark, rusty color, which beds, in steeply erected 

 position crossing the river bed diagonally, give a cause to falls eight or ten feet in 

 height. The exposed succession of beds amounts at the falls to a thickness of over 

 800 feet. Intermixture of jDyritous shaly seams with the quartzite beds, induces their 

 rapid disintegration on exposure, into shelly fragments covered with an iridescent 

 varnish like coating of oxide-hydrate. These beds are, in the embankments on the 

 opposite river side, remarkably corrugated, describing in their flections perfect coils.^ 



CHARACTER OF THE ORE. 



The ore obtained from the Crystal Falls district is chiefly soft red 

 hematite, though in places it is hydrated and graded as brown hematite 

 (limonite). The ore is very porous and shows many crystal-lined cavities. 

 At places a hard steel hematite ore is found, which runs as high as 70 \:>er 

 cent metallic iron. This ore occurs in very small quantities associated with 

 the soft ores, and appears for the most -part to have formed in geodal 

 cavities. When the cavities are still partly open, the ore has botryoidal and 

 stalactitic forms. The ores are very similar to the ores of the Michigamme 



'Iron and copper regions of the Upper and Lower Peninsulas of Michigan, by C. Rominger: 

 Geol. of Mich., Vol. V, 1895, Pt. 1, p. 74. 

 -Ibid., p. 75. 



