. The Vermilion iron-bearing district of Minnesota : with an atlas . About one-fourth of a mile north of the southeast corner of sec. 1,T. 62 N., R 15 W., there are a number of fairly good exposures of the ironformation. This is here very intimately associated with greenstone, withwhich it is clearly infolded, both the jasper and the greenstone there lieing-cut by acid dikes. The belt in which this iron-formation material occurswas traced to the north of east by means of a number of discontinuousexposures for about 2J miles. There is a large exposure just north of thelittle lake on the section
. The Vermilion iron-bearing district of Minnesota : with an atlas . About one-fourth of a mile north of the southeast corner of sec. 1,T. 62 N., R 15 W., there are a number of fairly good exposures of the ironformation. This is here very intimately associated with greenstone, withwhich it is clearly infolded, both the jasper and the greenstone there lieing-cut by acid dikes. The belt in which this iron-formation material occurswas traced to the north of east by means of a number of discontinuousexposures for about 2J miles. There is a large exposure just north of thelittle lake on the section line, between sees. 5 and 6, T. 62 N., R. 14 is very much contorted, and represents a southwestward-plunginganticline. Mining has been done at this ])oint to a slight extent, someore having been brought to the surface, although none has been shipped. SOUDAN FORMATION. 205 A numbei* of explorations farther east along the same belt of rock havelikewise disclosed the presence of the iron formation, but thus far onlyvery small quantities of ore have been Fio. 3.—Sketch showing Soudan formation infolded in Ely greenstone, both cut by Keweenawan dolerite dike. South of Moose Lake small stringers of jasper have been observed at anumber of places, associated with the Ely greenstones, which are there wellexposed on the bare hills. On the narrow strip of land in the NW. 5 ofsec. 4, T. 63 N., R. 9 W., sepai-ating two small lakes, there are exposedseveral narrow belts of iron formation intimately associated with the 206 THE VERMILION IRON-BEARING DISTRICT. greenstone. Five distinct bands of iron-formation material were observed,each only a few paces in width, and in the belts farthest south theexposures were sufficiently good to show very well the intimate relationsof the srreenstone and the iron formation. The iron formation is very Xf^ Ogishke conglomerate I ron-beanng formationGreenstone
Size: 1542px × 1621px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, booksubjectgeology, bookyear1903
