Browsing by Author "Wahl, Timothy E."

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    Geologic map index of Minnesota, 2nd ed.
    (Minnesota Geological Survey, 1985-03) Wahl, Timothy E.; Kuhns, Mary Jo P.; Morey, G. B.
    The principal maps covering the entire state are: 77 (gravity); 208 (bedrock hyrogeology); 210 (Quaternary hydrogeology); 197 (Quaternary geology); 253 (peat deposits); 300 (geomorphic regions); 318 (bedrock geology;) 309 (bedrock geology); 443 (hydrologic units); 76 (aeromagnetic Intensity). Full references are given in the bibliography.
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    Information Circular 16. Minnesota Geological Survey Subsurface Geology Data Base: Water Wells
    (Minnesota Geological Survey, 1979) Holtzman, Richard C.; Wahl, Timothy E.
    Subsurface geologic information is essential to much of the research performed by the Minnesota Geological Survey. The principal research activities that draw upon this data are bedrock and surficial geologic mapping, hydrogeologic mapping, and mineral resource evaluation. In addition, the Minnesota Geological Survey provides subsurface geologic information to the public and to government organizations such as the Minnesota Department of Natural Resources, Minnesota Department of Health, Regional Development Commissions, Soil and Water Conservation Districts, and the U.S. Geological Survey. Each of these activities is made more efficient by maintaining subsurface data in computer data bases. The principal sources of subsurface geologic data are records of water-well drilling, engineering test boring, and mineral exploration drilling. These three different kinds of records vary in data content and quality. For this reason the Minnesota Geological Survey employs three separate but compatible subsurface geology data bases, one corresponding to each type of data source. This report describes the water-well portion of the subsurface geology data base. Water-well records contain high-quality water-level observations and low- to medium-quality geologic information on the materials encountered during drilling. In addition, they often include data on pumpage tests and well use, and a description of the well construction. Water-well data is used extensively in mapping by the Minnesota Geological Survey and is frequently supplied in map or tabular form to the public and to a wide variety of government organizations. Because the water-well data base includes Public Land Survey coordinates for each well, the data is readily transmitted to the Minnesota Land Management Information System. Water-well data so transmitted will be a major component of the newly created Systems for Water Information Management (SWIM) of the Water Planning Board. The purpose of this report is twofold: 1) to acquaint current and potential users of the water-well data base with its contents and usefulness, and 2) to serve as a detailed user's reference manual.
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    RI-24 Manganese Resources of the Cuyuna Range, East-Central Minnesota
    (Minnesota Geological Survey, 1981) Beltrame, R.J.; Holtzman, Richard C.; Wahl, Timothy E.
    The Cuyuna range, located in east-central Minnesota, consists of a sequence of argillite, siltstone, iron-formation, graywacke, slate, and quartzite of early Proterozoic age. Manganese-bearing materials occur within the iron-rich strata of the Trommald Formation and the Rabbit Lake Formation. Computer-assisted resource estimates, based on exploration drill hole information, indicate that the Cuyuna range contains a minimum of 176 million metric tons (MMT) of marginally economic manganiferous rock with an average grade of 10.46 weight percent manganese. The calculated 18.5 MMT of manganese on the Cuyuna range could supply this country's needs for this important and strategic metal for nearly 14 years. An additional resource of 6.9 MMT of manganese metal is available in the lower grade deposits. The vast majority of these calculated resources are extractable by current surface mining techniques.