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Geology-Mineral District

In Silliman's American Journal of Science and Arts for July 1842, is an article by James T. Hodge, "on the Wisconsin and Missouri Leaf Region", which contains the most correct account that has recently been published, of the manner in which the lead is found in the rock; the general character of the mineral country, &c. [that] it is therefore hoped that no apology is necessary for introducing here the following extract.

"Though the cliff [Geodiferous] limestone, the rock [in which] formation that contains the lead ore, occupies a greater extent of country, it is in this portion only that circumstances seem to have been favorable for the production of fissures containing the ore. This rock is not broken through by granite or other rock of igneous origin, as the limestone of Missouri is, that there produces the ore. Its strata appears uniformly horizontal, until by tracing them some miles, a prevailing dip to the south is discovered. The lead region is a rolling hilly country, the hills sometimes covered with an open growth of oak, but as often entirely free from timber, and clothed with the tall prairie grass only. The summits maintain a general level, except where it is broken by the "natural mounds" ([The] Two Blue

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