...upper part of the Platteville limestone, both of Ordovician age. The ores are galena, smithsonite, and sphalerite, though the two latter are much less...of northern Illinois, Wisconsin, and Iowa has been large in the past and the ores have been smelted near the mines,1 the output in recent years has been...

...the upper part of the Platteville limestone, both of Ordovician age. They are galena, smithsonite, and sphalerite, though the two latter are much less...of northern Illinois, Wisconsin, and Iowa has been large in the past, and the ores have been smelted near the mines, the output in recent years has been...

...upper part of the Platteville limestone, both of Ordovician age. The ores are galena, smithsonite, and sphalerite, though the two latter are much less...were mined and the ore was taken from shallow pockets hi quantities ranging from a few tons to several thousand. Although the lead output of northern Illinois,...

...limestone, both of Ordovician age. The ores are galena, sphalerite, and smithsonite, though the latter is much less common now than formerly, when the deposits...worked were mostly shallow and above water level. The galena is practically nonargentiferous, and the zinc ores are not known to contain cadmium. SUver....

...upper part of the Platteville limestone, both of Ordovician age. The ores are galena, smithsonite, and sphalerite, though the two latter are much less common now than formerly, when the deposits NOBTHKBK ILLINOIS. 1915 1916 Total crude ore short tons. . 316,000 288,100 Total concentrates In crude...

...the upper part of the Platteville limestone, both of Ordovician age. They are galena, smithsonite, and sphalerite, though the two latter are much less...of northern Illinois, Wisconsin, and Iowa has been large in the past, and the ores have been smelted near the mines, the output in recent years has been...

...the upper part of the Platteville limestone, both of Ordovician age. They are galena, smithsonite, and sphalerite, though the two latter are much less...of northern Illinois, Wisconsin, and Iowa has been large in the past, and the ores have been smelted near the mines, the output in recent years has been...

...the upper part of the Platteville limestone, both of Ordovician age. They are galena, smithsonite, and sphalerite, though the two latter are much less...of northern Illinois, Wisconsin, and Iowa has been large in the past, and the ores have been smelted near the mines, the output in recent years has been...

...upper part of the Platteville limestone, both of Ordovician age. The ores are galena, smithsonite, and sphalerite, though the two latter are much less...output of northern Illinois, Wisconsin, and Iowa has Deen large in the past and the ores have been smelted near the mines,1 the output in recent years has...

...upper part of the Platteville limestone, both of Ordovician age. The ores are galena, smithsonite, and sphalerite, though the two latter are much less...quantities ranging from a few tons to several thousand. Some idea of the importance of the early mining of galena can be formed by the figures of production...