. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. UNCONFORMITY ON KETTLE EIVER. 245 in the bed of the stream, or in cliffs 20 to 75 feet high, on either side, for 5 miles, to the north line of Sec. 35, T. 43, R 20 W. Above this for 3J miles the sandstone does not appear in the river, but is seen here and there on hillsides near the stream. Throusfh sections 11 and 3, T. 43, R. 20 W. the sandstone reappears in the stream, the last exposure found lying 200 paces south of the north line of section 3. From this point up stream for some
. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. UNCONFORMITY ON KETTLE EIVER. 245 in the bed of the stream, or in cliffs 20 to 75 feet high, on either side, for 5 miles, to the north line of Sec. 35, T. 43, R 20 W. Above this for 3J miles the sandstone does not appear in the river, but is seen here and there on hillsides near the stream. Throusfh sections 11 and 3, T. 43, R. 20 W. the sandstone reappears in the stream, the last exposure found lying 200 paces south of the north line of section 3. From this point up stream for some nine miles no exposures were found. Then, through sections 9 and 4, of T. 45, R. 20 W., and 32, 29, and 28, of T. 46, R. 20 W., frequent out- crops of mica-schist are met with in the hillsides near the river. These briefly-stated facts with regard to the region of the Snake and Kettle rivers, fui'ther illustrated by the map of Plate XXIV, will serve to render certain three very important conclusions, viz: (1) the diabases and diabase-amygdaloids and interbedded Fig. 8.—Map of Exposures on Kettle River, Sec. „ , . _ 22, T. 41, E. 20 W., Minnesota. Scale 4 inches to porphyry-conglomerates ot this dis- the mile. trict are in all respects like those of Keweenaw Point; (2) the light-colored horizontal Cambrian sandstones overhe these bedsunconformably; (3) these Keweenawan beds, with a trend but little east of north, present an easterly dip which at from 5 to 8 miles west of the Saint Croix reaches 50° to 7o° and which flattens rapidly eastward, becoming very low on the Saint Croix ^Sevpse-nxx:mm- d^'^frect^o'^. Fig. 9.—Section on line A B of Fig to the inch. 8. Scale, horizontal, 8 inches to the mile; vertical, 300 feet itself The first two of these conclusions are but confirmations of those reached farther down the Saint Croix, but the last is of the greatest interest. Please note that these images are extracted from scanned page images that may have been digitally enhanc
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectgeology, bookyear1883
