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anticlinal appears basin beds belt border boundary branch Brandywine character Chester county clay close color containing continuous corner covered creek crosses crystalline crystals Delaware deposits described direction distance dyke east eastern edge evidently exposures extends feet follows Forge formation fragments further gneiss granite half hill hornblendic iron latter lead less lime limestone lode lower mass Mesozoic mica mica-schists micaceous mile mill mineral mines narrow nearly northern observed occurs opened outcrop passes Potsdam present Primal probably Prof quarry quartz quartzite range region ridge river road rocks Rogers sand sandstone schists Schuylkill seems serpentine short side slate South Valley southern station stone strata strike structure surface syenite synclinal thickness tion town township trap trough true upper Valley Valley hill vein western westward whole
Seite i - Board of Commissioners of Geological Survey, In the office of the Librarian of Congress, at WASHINGTON, DC Electrotyped and printed by LANE S.
Seite 197 - It would seem to be a pretty general fact, that such of these veins as are confined entirely or chiefly to the gneiss bear lead as their principal metal, whereas those which are included solely within the red shale are characterized by containing the ores of copper. But the zinc ores, viz: zinc-blende and calamine, prevail in greater or less proportions in both set of veins, existing, perhaps, in a rather larger relative amount in the copper-bearing lodes of the red shale.
Seite 30 - Colonies in America, and to prevent the Erection of any Mill or other Engine for slitting or rolling of Iron, or any plating Forge to work with a Tilt Hammer, or any Furnace for making Steel in any of the said Colonies...
Seite 197 - ... its average width at not less than eighteen inches. It is bounded by regular and well-defined, nearly parallel walls, the prevailing material of which is a coarse, soft granite, composed chiefly of white feldspar and quartz. " It would seem to be a pretty general fact that such of these veins as are confined entirely or...