. The Vermilion iron-bearing district of Minnesota : with an atlas . ^ together, they are se-pa-rated by a narrow area usually marked by a small topographic depression 272 THE VERMILION IRON-BEARING DISTRICT. in which uo rocks are exposed or in which there is only an occasional iso-lated exposure of rotten schistose rock. In such exposures the characters Corner. ALGONKIAN UOWER I^URONIAN Ogishke conglomerate ARCHEAN Granite Granite porphyry (with observed (withoutobserved strike and dip) strikeand dip) ScaleO 1/4. /a mile Fio. 17.—DLtiiil geologic map sliuwing exposures in u smiill iiruii on W
. The Vermilion iron-bearing district of Minnesota : with an atlas . ^ together, they are se-pa-rated by a narrow area usually marked by a small topographic depression 272 THE VERMILION IRON-BEARING DISTRICT. in which uo rocks are exposed or in which there is only an occasional iso-lated exposure of rotten schistose rock. In such exposures the characters Corner. ALGONKIAN UOWER I^URONIAN Ogishke conglomerate ARCHEAN Granite Granite porphyry (with observed (withoutobserved strike and dip) strikeand dip) ScaleO 1/4. /a mile Fio. 17.—DLtiiil geologic map sliuwing exposures in u smiill iiruii on West linll Luke. ARCHEAN GRANITES. 273 of this rock can not be definitely recognized in all cases, but since it isanalogous in all respects to the material described above as occurringbetween the granite and the clearly recognizable sediments, it is assumedto be the schistose arkose that lies between the granite and the overlyingsediments. These sediments consist of interbedded slates, gray wackes, andconglomerates, and. in these conglomerates pebbles were observed whichcould be identified with the granite of Saganaga Lake. After a study ofthe exposures here there can be no reasonable doubt that the sediments areyounger than, and partially derived from, the adjacent granite of SaganagaLake. Within the area shown on the map forming fig. 17 there is a kno
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectgeology, bookyear1903
