. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. COPPEE EANGE OP DOUGLAS COUNTY, WISCOI^SIN. 255 are from one half iucli to two feet tliick, 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 Fig. 11. Section in tlie gorge of Copper Creek, Doiigla Talus. 3. Broken and inclined sandstone. NW: i Co., Wis. (Afcer Sweet.) 1. Diabase. 2. 4. Horizontal red sandstone. The following section illustrates the relations of the dia
. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. COPPEE EANGE OP DOUGLAS COUNTY, WISCOI^SIN. 255 are from one half iucli to two feet tliick, 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 Fig. 11. Section in tlie gorge of Copper Creek, Doiigla Talus. 3. Broken and inclined sandstone. NW: i Co., Wis. (Afcer Sweet.) 1. Diabase. 2. 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. ' 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. * * * * 2 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 Eiver, in Sec. 17, where it divides into two or three general lines, the individual outcrops lapping past each other, and each preserving its trend of IST. 55° to 60° B. The second passes north- easterly across Sec. 12, and Sees. 7 and 8, T. 47, E. 13 W. Here the exposures are not numerous, but are in a nearly straight line. Most of them are in theTorm of short ridges. * * * * Upon Sec. 1, directly southeast from the W
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectgeology, bookyear1883
