. The Vermilion iron-bearing district of Minnesota : with an atlas . be seen fromthe map, the strike follows very closelythe outcrop of the greenstone. (3n the northern slope of the green-stone ridge which forms a subordinateanticline at the southwest end of OgishkeMuncie Lake, another contact was foundbetween the Ogishke conglomerate andthe greenstone. The contact occurs onthe hillside at a place 225 paces south and20 paces west of a point on the shoreopposite and just south of the west endof the westernmost island shown on themap (PI. XVI, atlas). The conglon^eratehere is fine grained and co
. The Vermilion iron-bearing district of Minnesota : with an atlas . be seen fromthe map, the strike follows very closelythe outcrop of the greenstone. (3n the northern slope of the green-stone ridge which forms a subordinateanticline at the southwest end of OgishkeMuncie Lake, another contact was foundbetween the Ogishke conglomerate andthe greenstone. The contact occurs onthe hillside at a place 225 paces south and20 paces west of a point on the shoreopposite and just south of the west endof the westernmost island shown on themap (PI. XVI, atlas). The conglon^eratehere is fine grained and consists of greenstone pebbles with occasional jasperpebbles. Tlie conglomerate is coarsest near the eruptive greenstone andgrows progressively finer northward, evidenth grading upward into theslates that occupj^ the central portion of Ogishke Muncie Lake. The large island northeast of the east end of this same greenstoneanticline well deserves examination, as it shows the relations of the green-stone and the conglomerate. The large-scale sketch (fig. 20) shows the. 200 feet Fig. 20.—Sketch showing relationship of Ely green-stone and overlying Ogishke conglomerate onisland in Ogishke Muncie Lake. THE LOWER HUEONIAN. 323 distribution of the rocks. The conglomerate occurs both north and southof the greenstone, but on the east side of the island near the top of the hillthere is a small area of slate and conglomerate which is clearly a part ofthe Ogishke conglomerate that was infolded in the underlying greenstoneand has not been completely removed by erosion. When this greenstone anticline which occurs at the southwest endof Ogishke Muncie Lake and also on the island just described is followedeastward along the south side of the lake, it is found to disappear for adistance of about one-third of a mile, it having plunged down under theconglomerate, which has not been eroded deep enough to show thegreenstone. It reappears again near the north-south section line betweensees. 27 and 26
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectgeology, bookyear1903
