Pio 
COPPER RANGE OF DOUGLAS COUNTY, WISCONSIN. 25D 
are from one half inch to two feet thick, often finely cross-laminated, and frequently 
show most beautiful ripple marks. They are also finer grained, and of a much lighter 
red color than the broken layers. 
Base Line,189' above L. Superior. <= It 
Fic. 11. Section in the gorge of Copper Creek, Douglas Co., Wis. (After Sweet.) 1. Diabase. 2 
Talus. 3. Broken and inclined sandstone. 4. Horizontal red sandstone. 
The following section illustrates the relations of the diabases and sandstones in 
the left bank of the creek. On the opposite side they were not exposed together. It 
will be observed that conglomerate and breccia do not occur. No sandstones were 
observed in the vicinity of Copper creek, except in the banks of the stream. 
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= * * * * * * * 
1 About one mile northeast from the mining location at Copper creek, there com- 
mences a very remarkable exposure. It is in the form of a rock ridge or great wall of 
stone, almost perfectly straight, nearly a mile long, 40 feet high, jagged and nearly 
vertical on the north side; the top, for a considerable distance, as smooth and level as 
a sidewalk, from 10 to 30 feet wide; the south side, even and sloping, and 20 or 30 feet 
above the soil. * * * * *The trend of the ridge is N. 55° E., which is exactly the 
direction of the strike, and the dip is 36° S. 
Passing off from the eastern end of this exposure, there are two lines of similar, 
but much smaller, outcrops. One goes nearly east to the Aminicon River, in See. 17, 
where it divides into two or three general lines, tbe individual outerops lapping past 
each other, and each preserving its trend of N.55° to 60° E. The second passes north- 
easterly across Sec. 12, and Sees. 7 and 8, T. 47, R.13 W. Here the exposures are 
not numerous, but are in a nearly straight line. Most of them are in the’form of short 
ridges. * * * * Upon See. 1, directly southeast from the Wisconsin mine, 
exposures are very numerous. They are usually short and ridge-like, varying in length 
from a few feet to an eighth of a mile; in width, at the surface of the dritt, from ten or 
20 to 200 feet; and in height from ten to seventy-five feet. They trend from 20° to 30° 
east of north; somewhat nearer north, it will be observed, than those a few miles to the 
west. They are separated from each other by drift-filled valleys from 100 to 700 feet 
wide. A short distance to the east of most of the small ridges is one very prominent 
ridge, or rather mound-like exposure, several hundred feet long and 75 feet high. The 
northern face is very precipitous, and the bedding is very distinct. The dip is 30° to 
the 8. 60° E. 
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1Geology of Wisconsin, Vol. III, p. 345. 2 Do., p. 346. 
