Publications

Late Mississippian and Pennsylvanian sedimentary rocks form part of a regional system of aquifers and confining units in the central Lower Peninsula of Michigan. The upper part of the Pennsylvanian rock sequence constitutes the Saginaw aquifer, which consists primarily of sandstone. This sandstone aquifer overlies the Saginaw confining unit, which consists primarily of shale. The Saginaw confining

Chemical and stable-isotope data for water from wells completed in the Glaciofluvial aquifer in the central Lower Peninsula of Michigan were used to prepare maps that show the areal variation of 8180; distribution of dissolved solids, dissolved chloride, dissolved iron, and dissolved sulfate; and distribution of hydrochemical facies. Delta oxygen-18 values indicate the presence of modem meteoric w

Monroe County relies heavily on its aquifers and streams for drinking water, irrigation, and other ~ses; however, increased water use, high concentrations of certain constituents in ground water, and droughts may limit the availability of water resources. Although the most densely populated parts of the county use water from the Great Lakes, large amounts of ground water are withdrawn for quarry d

No abstract available.

Maps showing predevelopment freshwater heads were developed for the major aquifers in the Michigan Basin. The Michigan Basin is an isolated, regional ground-water-flow system consisting of a glaciofluvial aquifer and three bedrock aquifers separated by confining units. The bedrock aquifers investigated are the Saginaw, Parma-Bayport, and Marshall aquifers. Fractured sandstones within the bedrock a

Polychlorinated Biphenyls (PCBs) in the Great Lakes Despite being banned since the 1970's, polychlorinated biphenyls (PCBs) continue to pose a threat to the environment because of their persistence and toxicity to organisms ranging from minute algae to fish, waterfowl, and human beings. PCBs, a set of 209 related chlorinated organic compounds, had various industrial uses such as in hydraulic fluid

Substantial flowpath-related variability of 87Sr/86Sr is observed in groundwaters collected from the Trout Lake watershed of northern Wisconsin. In the extensive shallow aquifer composed of sandy glacial outwash, groundwater is recharged either by seepage from lakes or by precipitation that infiltrates the inter-lake uplands. 87Sr/86Sr of groundwater derived mainly as seepage from a precipitation-

Our current understanding of wetlands is insufficient to assess the effects of past and future wetland loss. While knowledge of wetland hydrology is crucial, groundwater flows are often neglected or uncertain. In this paper, groundwater inflows were estimated in wetlands in southwestern Wisconsin using traditional Darcy's law calculations and three independent methods that included (1) stable isot

Pretty Lake is a 64 acre, sandy-bottomed groundwater flow-through lake that has a history of hydrologic disturbance. Residents and regulators require a better understanding of lake-groundwater interaction to develop measures to protect the lake's hydrologic system and water quality. A groundwater flow model was constructed as a tool to synthesize field data collected at the site, delineate recharg

Chemistry and stable-isotope data for water from wells completed in the Marshall aquifer within the Michigan Basin were used to prepare maps that show area! variations of δ18O; distribution of dissolved solids, dissolved chloride, dissolved iron, and dissolved sulfate; and distribution of hydrochemical facies. Delta oxygen-18 values indicate the presence of modern meteoric water (δ18O approximatel

Sedimentary rocks of Mississippian age form the lower part of a regional aquifer system in the central Lower Peninsula of Michigan. Strata of the Michigan Formation, the Marshall Sandstone, and the Coldwater Shale were subdivided into an aquifer and two confining units on the basis of hydraulic properties. The Michigan confining unit consists of shale, limestone, dolomite, gypsum, anhydrite, and d

Electrical-resistivity logs and water-quality data were used to delineate the fresh water/saline-water interface in a 22,000-square-mile area of the central Michigan Basin, where Mississippian and younger geologic units form a regional system of aquifers and confining units.Pleistocene glacial deposits in the central Lower Peninsula of Michigan contain freshwater, except in a 1,600-square-mile are