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Aminicon amygdaloidal amygdules angle beds belt Black River Falls brecciated brecciated amygdaloid calcite carry copper cemented chalcocite chalcopyrite commonly conglomerate Copper Creek copper deposits copper occurs copper-bearing rocks Croix and Douglas Croix range Croix river deposits of copper dip and strike distance Douglas county Douglas range drift epidotized epidotized areas exploration exposed exposures farther fault line Fond du Lac fractures gabbro Geol geological map glacial grained horizontal igneous rocks inches interbedded junction Keweenaw Point Keweenawan traps Lac location Lake Superior sandstone lava flows Lower Keweenawan rocks luster mottled malachite melaphyre mile minerals Minong range Montrose location native copper northeast and southwest northwest quarter outcrops overlying paces pebbles Penokee places plate VII porphyritic prehnite quarter of Sec quartz quartz-porphyry reddish diabase rich seen shaft shales slope southeast strata stream sunk Survey test pit tion trench underlain Upper Keweenawan upper surface vein-like width
Page 85 - Economic Series.—This series includes those bulletins whose interest is chiefly practical and economic. C. Educational Series.—The bulletins of this series are primarily designed for use in the schools. The following bulletins have been issued: BULLETIN No. I. ECONOMIC SERIES No. 1. On the Forest Resources of Northern Wisconsin. F.
Page 36 - E. 13 W. In the NW \ of this quarter section several pits, or shafts, have been sunk. During the time the Survey parties were in this district there was no work being done at this locality, and the pits were full of water. Consequently no careful examination could be made. It is evident that the
Page 75 - 1.21 per cent. In regard to the richness of the deposits the foregoing analyses show that there are certain bodies of rock which contain sufficient copper to be termed copper ore. Ore which averages one per cent, of copper will, with the present prices, under favorable conditions and economic working produce a profit.
Page 61 - in these fractures in the Little Maude vein at the Fond du Lac location. A few small veins have been found which cut the rocks at a marked angle to the different layers, as at the Percival location. These contain the same minerals as the other veins already mentioned and also carry copper.
Page 27 - amygdaloidal flows (580 paces N. and 750 W.). Farther up the stream in Sec. 2 on the west bank, is a low ledge (765 paces N. and 870 W.) which is poorly exposed and lies mainly under the water. The rock is a hard, dark reddish amygdaloid. The amygdules are filled
Page i - last statement is the St. Croix river, which has cut down 100 or more feet into the unconsolidated drift deposits through which it flows. This river flows in a broad, flat-bottomed valley which is out of proportion to the size of the present stream. The valley was excavated when the St. Croix acted as the outlet for
Page 37 - The vein strikes nearly east and west and dips 75° to the north near the surface, but the dip varies to more nearly vertical a few feet below the surface. It is the expectation of the owners that this vein will widen out and become copper-bearing some feet below the surface. malachite in the vein. The latter
Page 40 - The principal explorations on this property have been in the Ki of SW i of K E. i of Sec. 27, T. 48 K, R. 10 W. Considerable work was done here a number of years ago, and work has been actively resumed recently. An old pit (1,303 paces
Page 60 - highly charged with this mineral. Commonly these epidotized masses are of roughly spherical form, and vary in diameter from an inch to several feet. With the epidote in such masses is much quartz, especially in the amygdules. The copper occurs in the amygdules and also scattered throughout the rock. Many of the occurrences of copper on the St.