. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. THE EASTERN SANDSTONE ON THE HUNGAEIAN EIVEE. 355. Fig. 31.—Section ou the. Hungarian River, Keweenaw Point. surfaces dii)ping N. W. 25° and S. 20° E.; and a few steps farther down the sandstone is seen lying perfectly flat In the same vicinity true bedding, as shown by the differences in the coarseness and coloring of the sandstone, gave dips of N. W. 10°, S. E. 20°, N. E 20°. The irregularities seem to be due, in a measure, to undermining on the sides of the ravine, but are also a
. The copper-bearing rocks of lake Superior / by Roland Duer Irving. Geology; Geology; Copper ores; Copper ores. THE EASTERN SANDSTONE ON THE HUNGAEIAN EIVEE. 355. Fig. 31.—Section ou the. Hungarian River, Keweenaw Point. surfaces dii)ping N. W. 25° and S. 20° E.; and a few steps farther down the sandstone is seen lying perfectly flat In the same vicinity true bedding, as shown by the differences in the coarseness and coloring of the sandstone, gave dips of N. W. 10°, S. E. 20°, N. E 20°. The irregularities seem to be due, in a measure, to undermining on the sides of the ravine, but are also apparently somewhat analogous to those described and figured on a pre- vious page as occurring on the gorge of Black River, in Douglas County, Wisconsin—i. e., are the product of faulting motion. In his account of the occurrence on the Hungarian River,^ Mr. M. E. WadsAvorth has represented the Eastern Sandstone as pi-esenting an gradu- ally increasing northwesterly dip, as it is followed up the stream, until it is plainly seen plunging beneath the Keweenawan diabase and interbedded conglomerate. But neither the increasing northwesterly dip nor the subor- dinate position of the sandstone to the diabase could be detected by Mr. Chauvenet. Northwesterly dips are found in the sandstone for some dis- tance below the contact, but southeasterly ones just as often, or oftener, and both seem distinctly subordinate to a general horizontality. Again, sand- stone lies vertically beneath an amygdaloid, but the mass of sandstone ap- pears to be a fallen one, and if it is riot, the crumbling amygdaloid above certainly is. The occurrences on the Douglas Houghton River are much like those seen on the Hungarian, with the exception that the true Keweenawan beds extend down stream for some 300 paces from the head of the ravine, for the reason that they include just here a considerable thickness of soft conglomerate. Below the last of these beds is a gap of some 200 paces, when the horizont
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