. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. UNCONFORMITY ON BLACK EIVER, WISCONSIN. 253 bed dips 42° to the N. 10° E. * * * * In this coDglomerate bed there are white quartz, gray quartzite, diabase and sandstone pebbles, with reddish sand as the cementing material. It forms so incoherent a mass that most of the pebbles may be readily picked out with the hand. In other respects it is very similar to the bed on. Fig. 10. Section on the gorge of Black Eiver, Douglas County, Wis. (after Sweet). 1. Diabase, ashbed type. 2. Felsit
. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. UNCONFORMITY ON BLACK EIVER, WISCONSIN. 253 bed dips 42° to the N. 10° E. * * * * In this coDglomerate bed there are white quartz, gray quartzite, diabase and sandstone pebbles, with reddish sand as the cementing material. It forms so incoherent a mass that most of the pebbles may be readily picked out with the hand. In other respects it is very similar to the bed on. Fig. 10. Section on the gorge of Black Eiver, Douglas County, Wis. (after Sweet). 1. Diabase, ashbed type. 2. Felsitic porphyry. 3. Gray diabase. 4. Eeddish-brown diabase. 5. Diabase-brec- cia. 6. Shaly sandstone. 7. Porphyry and qnartz-conglomerate. 8. Unexposed. 9. Broken and inclined red sandstone. 10. Horizontal red sandstone. Horizontal scale 300 feet to the inch. Ver- tical scale 150 feet to the inch. the west side of the stream. The space above the conglomerate for about 50 feet is covered with talus which has fallen down from the nearly vertical cliff of diabase. Many hundred tons weight have recently fallen from this cliff". All of the fragments are very small, angular, find much weathered. Numerous stains of copper carbonate were noticed in the fragments. The dip here appears to be 36° to the SE. On the opposite side of the stream, above the conglomerate, there are two small ex- posures of shaly sandstone. The upper exposure dips 29° to the S. 20° W., directly towards a diabase cliff' only 50 feet distant and 40 feet high. Clinging to the face of the cliff are, at two or three places, patches of diabase-breccia, a foot or more thick. Seventy-five or one hundred feet northwest from the cliff of diabase, in the wall of the gorge, dark-reddish and somewhat indurated sandstones are found. The layers at first are broken into blocks from 4 to 10 feet in length, and are inclined at various angles, usually to the NW. Gradually they assume more and more of a distinctly bedded stru
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectgeology, bookyear1883
