Wisconsin. Chief Geologist / Geology of Wisconsin. Survey of 1873-1879 ...
Volume II (1877)
[Chapter IV. The Lead region], pp. [unnumbered]-752 PDF (23.7 MB)
7352 GEOLOGY AND TOPOGRAPHY OF THE LEAD REGION. There is another method by which drainage of mines has sometimes been effected, and which might in many other places be employed to advantage. It is by simply drill- ing a hole from the bottom of the mine to some of the underlying clay beds of the Trenton. In this way a passage is often effected for the escape of the water, of whichl it will often avail itself until the opening becomes closed with niud from the mine, when a new hole has to be drilled. In many portions of the Lead region, but more especially in the southern and centra parts, there is a desire which has often been earnestly expressed to me, that a survey should be made of the ore-bearing ranges both old and new. Such a survey, to be of any practical benefit, should be made with a transit and level, and with the utmost accuracy. It should be made underground when possible, and when not, it should be miade on the surface, locating the ranges from the shafts. The survey of each district should be referred to certain fixed points, whose location and elevation should be accu- rately ascertained. The location of these points with reference to each other could at any time be ascertained by triangulation if thought necessary. The whole should then be mapped on a suitable scale and published with the field notes. The advantages derived from such a survey are chiefly the following: (1) In ranges which are now worked, it would be easy to reproduce on the surface the areas worked out below, and from the known course of the range the miner could, with considerable certainty, locate his shafts so as to reach the unworked portions, thus effecting a large saving of tine, labor and money wasted in prospecting. (2) The surface of the Lead region is rapidly becoming an agricultural country. In many places the old shafts are being filled, the dump piles are being removed, and all surface vestiges of once val- uable ranges are becoming obliterated. Many of these ranges were worked many years since for lead ore alone. to the natural water level, and abandoned with valuable bodies of ore still remaining in them; and in view of the increasing production of zinc ore, which is now between three and four times that of lead ore, it is not unlikely that it may become profitable to work them again. From a survey such as is outlined above, the location of old shafts and ranges could at any tinme be restored. (3) It would conduce to the systematic working of the mines in the future, by forming a basis to which private surveys could be referred, and would indicate the points where levels could be most successfully placed for the drainage of the mines. These are but a few of the advantages which will occur to persons actually engaged in mining. Probably there is enough money wasted in prospecting every year, which would be saved by such a survey, to carry it on to a successful termination.
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