Geology topics

M.G. Sherrill

Publications and source records attributed to M.G. Sherrill.

4 recordsLinked to original sources

USGS1987

Hydrogeology of the Cambrian-Ordovician aquifer system at a test well in northeastern Illinois

A 3,475-ft-deep test well was drilled in northeastern Illinois near Lake Michigan and the Illinois-Wisconsin State line as part of a regional hydrologic study of the Cambrian-Ordovician aquifer. The well penetrates the Cambrian-Ordovician aquifer system and 40 ft of Precambrian granite. From oldest to youngest the aquifer system consists of the lower Mount Simon aquifer, Mount Simon confining unit, Elmhurst-Mount Simon aquifer, Eau Claire confining unit, Ironton-Galesville aquifer, Franconia confining unit, St. Peter aquifer, and an upper confining unit composed of the Glenwood Formation, Galena Dolomite and Platteville Limestone, and Maquoketa Shale. Aquifer tests were performed on hydrogeologic units that were isolated with inflatable packers. Results indicate that the Ironton-Galesville aquifer has the highest hydraulic conductivity - 10 ft/day. The St. Peter and Elmhurst-Mount Simon aquifers have hydraulic conductivities of 1.8 and 1.5 ft/day, respectively. The Mount Simon confining bed has a hydraulic conductivity of 1.3 ft/day. The Mount Simon confining unit confines saline water present in the lower Mount Simon aquifer. The dissolved solids concentration in water from this aquifer is > than 55,000 mg/L, and the head is at least 50 ft higher than heads in any of the overlying Cambrian and Ordovician aquifers. (USGS)

Water-Resources Investigations Report↗

USGS1984

Illinois ground-water observation network; a preliminary planning document for network design

Water-level and water-quality networks in Illinois were evaluated to determine the adequacy and completeness of available data bases. Ground-water data in present data bases are inadequate to provide information on ground-water quality and water levels in large areas of Illinois and in the major geohydrologic units underlying Illinois and surrounding areas. Data-management needs indicate that a new data base is desirable and could be developed by use of carefully selected available data and new data. Types of data needed to define ground-water quality and water levels in selected geohydrologic units were tentatively identified. They include data on concentrations of organic chemicals related to activities of man, and concentrations of inorganic chemicals which relate either to man 's activities or to the chemical composition of the source aquifer. Water-level data are needed which can be used to describe short- and long-term stresses on the ground-water resources of Illinois. Establishment of priorities for data collection has been deferred until existing hydrologic data files can be stored for usable data and until input from other local, State, and Federal agencies can be solicited and compiled. (USGS)

Open-File Report↗

USGS1979

Contamination potential in the Silurian Dolomite aquifer, eastern Wisconsin

The Silurian dolomite aquifer is used for water supply in much of a 14-county area bordering Lake Michigan in eastern Wisconsin. Because of the rapidity of ground-water movement, the aquifer is susceptible to contamination by waters percolating downward from surface sources. Maps showing the distribution of permeability, the thickness of unconsolidated materials, and the depth to the water table are combined to show areas where the dolomite aquifer has the greatest contamination potential. Several areas have above-normal potential for contamination. These include the Casco-Luxemburg area of Kewaunee County, the area south of Chilton in Calumet County, a part of western Manitowoc County, drainageway areas in Sheboygan County, the Byron-Campbellsport area of Fond du Lac County, the Sussex-Lannon-Cedarburg areas of Waukesha and Ozaukee Counties, and the Racine-Burlington areas of Racine County.

Wisconsin↗

USGS1979

Water-table map of Kenosha County, Wisconsin

A map (scale 1:100,000) of the water table in Kenosha County in southeastern Wisconsin was prepared using water levels from more than 200 wells. The work was done as a cooperative project between the U.S. Geological Survey and the Southeastern Wisconsin Regional Planning Commission. The map shows the altitude of the water table in increments of 20 feet, with supplemental 10-foot contours. The altitude ranges from less than 580 feet at a point near Lake Michigan to more than 840 feet at a point near the western border of the county. (Woodard-USGS)

Wisconsin↗