Geology topics

J. F. Ruhl

Publications and source records attributed to J. F. Ruhl.

23 records · Page 2Linked to original sources

USGS1983

Hydrogeologic and water-quality characteristics of the Prairie du Chien-Jordan aquifer, Southeast Minnesota

Quality of water in the Prairie du Chien-Jordan aquifer is generally good, except for some localized contamination, Coal-tar derivatives that contaminate the aquifer in St. Louis Park, a western suburb in the Twin Cities Metropolitan Area, pose the most serious threat to water quality. High hardness and iron concentration limit suitability for municipal and industrial use in parts of extreme southeast Minnesota. Confining beds of bedrock and drift, however, protect most of the aquifer from surface pollutants. The Prairie du Chien-Jordan aquifer is part of a sequence of sedimentary bedrock units in southeast Minnesota. The Jordan Sandstone is a white to yellow, fine- to coarse-grained sandstone. The Prairie du Chien Group comprises two dolomitic formations that are vuggy and fractured and interbedded with thin layers of shale. The aquifer formations were deposited in Paleozoic seas that occupied the Hollandale embayment. The aquifer dips toward the interior of the embayment where it is as deep as 750 feet below land surface and as thick as 500 feet. Permeability is secondary in the Prairie du Chien Group because of solution cavities and fractures, and intergranular in the Jordan Sandstone. Water in the aquifer is confined except in the eastern part. Water generally flows to the north and east into the Minnesota and Mississippi Rivers. A ground-water divide separates part of the flow southward into Iowa. This aquifer supplies more water than any other bedrock one in the State. Calcium magnesium bicarbonate type water is most common in the aquifer. Calcium and sulfate and, to a lesser degree sodium and magnesium, increase in concentration toward the southwestern part of the study area. Bicarbonate concentration, on the other hand, decreases toward the southwestern corner of the study area. Leakage from overlying Cretaceous deposits is the source of much of the sulfate and other minerals in the southwest. This report is one of a series on the hydrogeology and water quality of the 14 principal aquifers in Minnesota prepared by the U. S. Geological Survey. The U. S. Environmental Protection Agency requested these studies because of the need for information to develop its Underground Injection Control Program.

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USGS1983

Hydrogeologic and water-quality characteristics of the St. Peter aquifer, Southeast Minnesota

Quality of water in the St. Peter aquifer is generally acceptable for most uses. Sulfate concentrations increase toward the southwestern part of the aquifer because of highly mineralized leakage from overlying Cretaceous deposits. Concentrations of sodium, magnesium, and sulfate generally increase to the west, and those of calcium, bicarbonate, and chloride generally increase toward the margins of the aquifer. Calcium magnesium bicarbonate water is the most common type in the aquifer. The aquifer is well protected from surface sources of Contaminants by the overlying Decorah-Platteville-Glenwood confining bed, which overlies about 80 percent of the St. Peter aquifer. Thin drift, which overlies the east side of the aquifer, provides much less protection than the confining bed. Water in the aquifer generally flows toward the Mississippi River and its tributaries. Some water flows southward into Iowa from a ground-water divide in Dodge and Steele Counties, Well yields from the aquifer, which are generally between 100 and 250 gallons per minute, are generally adequate for most uses. This report is one of a series on the hydrogeology and water quality of the 14 principal aquifers in Minnesota prepared by the U.S. Geological Survey. The U. S. Environmental Protection Agency requested these studies because of the need for information to develop its Underground Injection Control Program.

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USGS1983

Hydrogeologic and water-quality characteristics of the Upper Carbonate aquifer, Southeast Minnesota

The Upper Carbonate aquifer is part of a sequence of sedimentary bedrock units deposited in Paleozoic seas that occupied a depression known as the Hollandale embayment. The aquifer is comprised of four formations, which, in ascending order, are the Galena Dolomite, Dubuque Formation, Maquoketa Shale, and Cedar Valley Limestone. Total thickness of the aquifer is as much as 650 feet. Yields from wells in the aquifer range from about 100 to 500 gallons per minute. Water flows mostly through fractures and solution channels toward the periphery of the aquifer and, locally, toward river and bedrock valleys. The quality of water in the Upper Carbonate aquifer is suitable for most uses. However, the water is susceptible to contamination in karst areas because sinkholes and disappearing streams provide direct passageways for entry of contaminants into the aquifer. Calcium magnesium bicarbonate type waters are most common. Concentrations of dissolved solids and some major ions, specifically magnesium, sodium, bicarbonate, and sulfate, are generally highest in the southwestern part of the study area.

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USGS1982

Hydrogeologic and water-quality characteristics of the Ironton-Galesville aquifer, southeast Minnesota

Quality of water in the Ironton-Galesville aquifer is generally acceptable for all kinds of uses. Calcium magnesium bicarbonate type water is most common. The dissolved-solids concentration ranges from about 200 to 1,000 milligrams per liter. The lowest values are in the northern part of the aquifer, where the bedrock is at or close to land surface, and the lowest ones are in the southwestern part, where leakage into the aquifer from overlying Cretaceous deposits is highly mineralized water. The concentrations of the major ions, except for bicarbonate and chloride, also increase toward the southwest. Confining beds protect the aquifer from surface pollutants, but high sulfate and iron concentrations and hardness degrade water quality locally in some places. The aquifer was deposited from Paleozoic seas that occupied a shallow depression known as the Hollandale embayment. The surface of the Ironton-Galesville aquifer dips toward the interior of the embayment. The aquifer is as deep as 1,000 feet below land surface and as thick as 325 feet. The Ironton and Galesville Sandstones are both white and medium grained. The aquifer is used mainly in the northern and western parts of the study area, where it is the uppermost bedrock aquifer, This report is one of a series on the hydrogeology and water quality of the 14 principal aquifers in Minnesota prepared by the U.S. Geological Survey. The U.S. Environmental Protection Agency requested these studies because of the need for information to develop its Underground Injection Control Program.

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USGS1981

Designation of principal water-supply aquifers in Minnesota

Fourteen aquifers, ranging from Quaternary to Precambrian in age, have been identified as the principal sources of water to wells in Minnesota. Half the municipal population anc nearly all the rural population depend on water from these aquifers. Buried and surficial sand and gravel aquifers of Quaternary age occur in nearly all areas of the State and are composed of outwash, beach-ridge, valley-train, and ice-contact deposits. Cretaceous aquifers, absent in the northeast, are nearly continuous in the western half, and are thin or discontinuous in the central and southeast areas. Sandstone and carbonate rocks of Paleozoic and late Precambrian age in southeastern and northwestern Minnesota comprise the Cedar Valley-Maquoketa-Dubuque-Galena, Red River-Winnipeg, St. Peter, Prairie du Chien-Jordan, Franconia-Ironton-Galesville, and Mount Simon-Hinckley-Fond du Lac aquifers. Aquifers of early Precambrian age occur in all but southeastern Minnesota and include the North Shore Volcanic Group, Sioux Quartzite, Proterozoic metasedimentary rocks, Biwabik Iron-formatIon, and undifferentiated Precambrian rocks. The State's ground water generally contains less than 1,000 milligrams per liter of dissolved solids, except in the extreme southwest, northeast, and western areas. Mineralized water is present at depth throughout the State. Freshwater extends to depths of about 1,000 feet in the center of the Hollandale embayment and in the Twin Cities basin. Six principal water-quality types are present in the .aquifers. Calcium magnesium bicarbonate type water, the most common, is generally present throughout the upper part of the ground-water system.

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