E/MJ : engineering and mining journal . ult ornot is somewhat doubtful. The throw is probably atright angles to the dip of the formation. From all theinformation at present available, the fault is approxi-mately vertical in its dip, and the strike, as shovim inFig. 24, is approximately northwest. The main move-ment along this fault plane occurred when the bedsof the iron formation series were horizontal, beforeany appreciable tilting had taken place. The beds onthe east side of the fault were then over-thrust upwardin a westwardly direction. Associated with this thrustfault there was folding a
E/MJ : engineering and mining journal . ult ornot is somewhat doubtful. The throw is probably atright angles to the dip of the formation. From all theinformation at present available, the fault is approxi-mately vertical in its dip, and the strike, as shovim inFig. 24, is approximately northwest. The main move-ment along this fault plane occurred when the bedsof the iron formation series were horizontal, beforeany appreciable tilting had taken place. The beds onthe east side of the fault were then over-thrust upwardin a westwardly direction. Associated with this thrustfault there was folding and crumpling of the beds, asshown in the hill of Palms quartz slate at this fault occurred, there followed a period whichresulted in the complete erosion in some places of theTyler slates on the eastern side of the fault, so thatwhen the Keweenawan lava flows began to pour out,they, or Keweenawan conglomerates, rested in manyplaces directly upon the iron formation. So far as is indicated by information at present avail-. FIG. 24. MAP OF OF .SUNDAY LAKE F.\ M. C. Lake in •Iron Ores of Lake Superior. Crowell and .Minify. possible that they represent a fifth type of fault. Fault- able, this fault does not cut the Keweenawan traps, anding of the Eureka type has been definitely recognized though there may have been a later movement along thiswest of the Tilden mine only in a few cases of slight fault that has displaced the traps, there is no questiondisplacement, but it is not at all unlikely that larger that the major movement occurred before Keweena-faults of this type will be found. wan time. There is no evidence that the bedding fault 540 Engineering and Mining Journal Vol. 108, No. 13 cuts through the Sunday Lake fault, and, on the otherhand, bedding faults are known in the iron formationeast of the Sunday Lake fault. Though it is impossibleto say that these bedding faults correspond to thegreat bedding fault movement west of the Sunday Lakef
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Keywords: ., bo, bookcentury1900, bookdecade1910, booksubjectmineralindustries
