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Research about Minnesota

Source-linked reports with geographic coverage including Minnesota.

At least 811 records · Page 45Linked to original sources
USGS1975

Soil anomalies associated with Cu-Ni mineralization in the South Kawishiwi area, northern Lake County, Minnesota

Geochemical sampling in the contact zone between the Giants Range Granite and the Duluth Gabbro Complex along the South Kawishiwi River indicates the presence of extensive soil anomalies associated with the known Cu-Ni-Co-Ag mineralization in the basal part of the Duluth Gabbro Complex. A close spatial relationship was found between the ore bodies and associated anomalies, despite the fact that the parent material of the sampled soils was glacial overburden that mantles the area to a depth of 0-50 feet. The <74 mesh fraction of B-horizon soils was found to be an effective sample type for geochemical exploration in this area. Trace metals are believed to be held primarily by the clay-size hydrated iron oxides and manganese oxide, which are somewhat enriched in the fine fraction of the B-horizon soils.

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USGS1975

An appraisal of groundwater for irrigation in the Appleton area, west-central Minnesota

Supplemental irrigation of well-drained sandy soils has prompted an evaluation of ground water in the Appleton area. Glacial drift aquifers are the largest source of ground water. The surficial outwash sand and gravel is the most readily available and a really extensive drift aquifer and underlies much of the sandy soil area. Saturated thickness of the outwash is more than 80 feet (24 metres) in places and potential well yields may exceed 1,200 gallons per minute (76 litres per second) in some areas. In about 17 percent of the area, yields of more than 300 gallons per minute (19 litres per second) are obtainable. Recharge to the outwash aquifer occurs primarily during the spring thaw and averages about 5 inches (12.7 centimetres) annually. Most discharge from the aquifer appears as base flow in the Pomme de Terre River. Despite dissolved-solids concentrations ranging from 280 to 1,350 milligrams per litre the water is chemically suitable for irrigation.

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USGS1975

Configuration of water table and distribution of downward leakage to the Prairie du Chien-Jordan Aquifer in the Minneapolis-Saint Paul metropolitan area, Minnesota

The configuration of the water table as plotted at a contour interval of 20 feet (6 metres) on quadrangle maps (scale 1:2,500) of the Minneapolis-Saint Paul metropolitan area. Control points used for mapping were water levels in wells, lakes and sloughs, and places where topographic contours cross perennial streams. A computer program, using a variation of Darcy's law, was developed to determine distribution of 1) downward leakage to the Prairie du Chien-Jordan aquifer under steady-state conditions, using estimated vertical-hydraulic conductivity values for overlying materials; 2) calculated vertical hydraulic conductivity values, assuming uniform leakage to the aquifer; and 3) additional leakage to the aquifer resulting from increased pumpage during the summer. For data determination and data input to the computer program, the area was gridded into units of 1-minute longitude by 1-minute latitude, about 600 acres (243 hectares) per unit. Previous work estimated the increased summer pumpage (1971) of ground water to be 127 million gallons (481x106 litres) per day. Calculations, made Within the limits of governing assumptions, indicate that 10 to 20 percent of increased summer pumpage is derived from increased leakage. Most of the remainder is probably from captured natural discharge and induced recharge from major streams within the influence of summer cones of depression. Based on available data and estimates of vertical hydraulic conductivity for geologic units, major leakage to the Prairie du Chien-Jordan aquifer is indicated to occur in formation subcrop areas, especially where these areas are. overlain by the most permeable glacial drift.

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USGS1975

Some limnological aspects of 20 selected lakes in Eagan and Apple Valley, Minnesota

Selected physical, chemical, and biological parameters were determined to assess the quality of 20 lakes in the cities of Eagan and Apple Valley, Minn. All the lakes are eutrophic except Holland and Fish Lakes, which are mesotrophic. Some lakes (including Fish Lake) have storm sewer inlets but are not discernibly different in quality than lakes with no such inlets.

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USGS1975

A water-quality assessment of the Burnham Creek Watershed, Polk County, Minnesota

A water-quality assessment of the Burnham Creek watershed, Polk County, Minn., was made in May 1975. Surface waters were calcium magnesium bicarbonate types with 0.11 mg/liter or less of nitrite plus nitrate nitrogen and 0.10 mg/liter or less of total phosphorous. Fecal coliform bacteria concentrations were between 3 and 720 colonies per 100 milliliters and fecal Streptococci concentrations ranged between 19 and 1600 colonies per 100 milliliters. Pesticide concentrations were low in the stream bottom materials, but an increasing trend was apparent in the downstream direction. The benthic community was dominated by blackfly larvae.

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USGS1975

Ground water for irrigation in the Viking Basin, west-central Minnesota

The Viking Basin consists of six glacial outwash areas in Douglas, Ottertail, and Todd Counties, west-central Minnesota. Total area is 340 square miles (880 square kilometres). Soils are sandy and excessively well-drained. Crops grown on the outwash would benefit from supplemental irrigation. Irrigation supplies can be obtained from wells in the surface outwash aquifer in significant parts of the large outwash areas near Carlos and Parkers Prairie and the small outwash area near Clotho. Irrigation supplies are unlikely in the outwash areas near Alexandria, Urbank, and Rose City. Major use of ground water for irrigation may lower ground-water levels sufficiently to affect lake and marsh levels and streamflow out of the irrigation areas. Water from the outwash is of excellent chemical quality for irrigation.

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USGS1975

Digital models of a glacial outwash aquifer in the Pearl-Sallie Lakes area, west-central Minnesota

-p^e need for study of lake-ground-water interchange has been accentuated by eutrophication of lakes in the Pearl-Sallie Lakes area of west-central Minnesota. The local ground-water flow system is dominated by an outwash aquifer that is sandwiched between two till layers in the western part of the area and exposed at the land surface in the eastern part. Ground water discharges from the aquifer into lakes in the outwash area but is recharged from lakes in the till-covered area. Irregular aquifer geometry resulted in a complex ground-water flow system. Simulation of the system by areal and vertical-section models showed that the lakes significantly control groundwater flow near their boundaries. Inadequate field data and complex geology caused difficulty in obtaining solutions with the vertical-section model. The models may be used to guide collection and interpretation of field data, and quantification of the ground-water flow system. With modification, they could be used to predict aquifer response to transient stresses. They also could be incorporated into more complex models to determine the movement of solutes in the ground-water system.

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USGS1974

3,800-Myr granitic gneiss in south-western Minnesota

WE have previously arrived at an age of 3,550 Myr for granitic 1 gneiss in the vicinities of Morton and Montevideo in the Minnesota River valley, south-western Minnesota. We now report new Rb–Sr analyses (Table 1) and an age of 3,800 Myr for the fine grained foliated phase of the Montevideo Gneiss of Lund 2 . The rocks have undergone a complex history of metamorphism which remains to be deciphered, but the age determinations reveal that the geological mapping and previous interpretations did not provide a proper basis for sampling.

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USGS1974

Effects of radio packages on wild ducks

A total of 211 wild, free-flying mallards ( Anas platyrhynchos ) and wood ducks ( Aix sponsa ) were equipped with breast-mounted radio packages during the breeding seasons of 1968-72. Known predation loss was 7.6 and 12.0 percent for mallards and wood ducks respectively, 60 percent occurred within 3 weeks of instrumentation. The highest predation rate for mallards was 0.0048 kills per tracking day and 0.0136 for wood ducks. A higher direct recovery rate for instrumented birds (19.5 percent) than noninstrumented birds (8.1 percent) was probably due to the novelty of the transmitter to hunters. Departure patterns and locations of direct recoveries were similar between radio-equipped and normal-banded birds. Among female wood ducks with radios, recovery rates were lower than expected. Hunters indicated that 84 percent of the instrumented ducks recovered were in good or excellent condition. Recaptures of ducks as long as 1 year after being equipped with radio packages indicated that feather wear and skin abrasion were not serious. A high rate for feeding on land by instrumented mallards was probably due to our ability to more easily locate and observe these birds in cover. Preening rates were higher for instrumented ducks. As the birds became adjusted to the package, preening decreased and feeding on water increased. Social and breeding behavior of instrumented ducks did not appear to be adversely affected by the radio package.

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USGS1974

Remote sensing for identification and classification of wetland vegetation

Multispectral photography and ground truth were obtained on an area 12 miles (19.3 km) east of Bemidji, Minnesota, to identify and map wetlands less than 2 acres (0.8 hectare) in size, to map emergent vegetation in lakes, and to explore the feasibility of classifying vegetation from aerial photographs. Wetlands less than 2 acres in size were identified on photography taken in May 1971, and emergent vegetation was recorded on purposely overexposed infrared black and white photography from a flight in September 1971. Several vegetation types and species groups were recognizable with the aid of color, color infrared, and black and white infrared photography. Proper timing of flights, use of multispectral photography, and knowledge of the ecology of the area are considered essential for wetland mapping by remote sensing.

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USGS1974

Water resources of the Snake River watershed, east-central Minnesota

Glacial drift overlies sedimentary, igneous, and metamorphic rocks in the Snake River watershed. The Snake River, which drains an area of about 1,030 square miles, originates in an extensive area of peat bogs in the northern part of the watershed. It flows southward across gently rolling glacial terrain in which the major relief is near the river. Near the southern boundary of the watershed, the Snake River turns eastward to its confluence with the St. Croix River. The northwest half of the watershed is heavily forested, whereas much of the southeast half has been cleared. The largest communities in the watershed, Mora and Pine City, had 1970 populations of 2,582 and 2,143, respectively.

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USGS1974

Water resources of the lower St. Croix river watershed, east-central Minnesota

The lower St. Croix River watershed is an elongate area of about 930 square miles bounded on the east by the St. Croix River. The St. Croix River forms the Minnesota-Wisconsin boundary along the eastern side of the watershed. Additional drainage to the St. Croix River includes areas of about 2,500 square miles upstream in Minnesota and about 4,340 square miles in Wisconsin. At the southern tip of the watershed, the St. Croix joins the Mississippi River. Because part of the St. Croix River is deeply entrenched, topography in the watershed ranges from relatively rugged in highly dissected areas near the river to nearly flat in the west-central area. In the southern third of the watershed and along the St. Croix River, many outcrops of Ordovician, Cambrian, and Precambrian bedrock occur. The remainder of the watershed is covered by glacial deposits whose maximum thickness is about 400 feet. Much of the original forest cover, primarily hardwoods, has been removed; the largest concentrations remaining are long the St. Croix River and in the west-central area. The proximity of the watershed to the expanding Minneapolis-St. Paul metropolitan area emphasizes the importance of defining water resources essential for future growth.

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USGS1974

Water resources of the Rum River Watershed, east-central Minnesota

The Rum River, a tributary of the Mississippi River, drains an elongate area of about 1,550 square miles. The source of the Rum River is Mille Lacs Lake. Much of the northern half of the watershed is forested, and there are large areas of swampland. Population is most concentrated in the southern half, where agriculture is the dominant economic activity. Except for scattered Precambrian igneous rock outcrops in the central third of the watershed, bedrock is covered by glacial drift. In the southern third, the drift includes considerable amounts of outwash and is directly underlain by Cambrian and Precambrian sedimentary rocks. Greatest topographic relief is in morainal areas around Mille Lacs Lake. The central third of the watershed slopes gradually southward, grading into the relatively flat area of surficial outwash.

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USGS1974

Water resources of the Cannon River watershed, southeastern Minnesota

The 1,462 square miles of land surface in the Cannon River watershed varies considerably from areas of low hills and plains to areas dominated by streams deeply incised into bedrock. Much of the south-central part of the area consists of a till plain that ranges in altitude from 1,100 to 1,200 feet above mean sea level. This plain is bordered by end moraines that form ridges on the east, west, and south. The eastern moraine marks the maximum eastward extend of the Wisconsin glacier, rising to more than 1,300 feet above sea level and forming ridges 50 to 100 feet above the till plain. In the northwest, the end moraine ridges are less obvious but extend directly north across the Cannon River valley. The end moraine ridges were cut by glacial melt water, which also deepened the pre-existing Cannon River valley. This deeply incised valley captures some of the streams that flow westward off the end moraines. East of the end moraines, pre-Wisconsin age glacial deposits are relatively thin and deeply weathered and eroded. Lard glacial melt-water valleys, around Cannon Falls and extending several miles to the west and south west, are characterized by broad valley floors underlain by outwash sand and gravel. The Cannon River flows out of the watershed and enters the Mississippi River at about 660 feet altitude.

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USGS1974

Water resources of the Blue Earth River watershed, south-central Minnesota

The Blue Earth River Watershed in Minnesota includes 3,106 square miles of land surface, which varies from fairly flat to gently rolling. The drainage extends south to include an additional 450 square miles in Iowa. The western, southern, and eastern boundaries are end moraines formed by Pleistocene glaciers. Major streams have eroded channels 40 to 75 feet deep in headwater regions and 150 to 200 feet deep near the mouth of the Blue Earth River at Mankato. In their lower reaches major streams have cut through glacial deposits and into underlying bedrock (described on ground-water sheet).

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USGS1974

Water resources of the Lower Minnesota River Watershed, south-central Minnesota

The lower Minnesota River watershed, an area of 2,005 square miles, is fairly flat west of the Minnesota River, but rises to a hilly ridge along the east side of the watershed. Most of the area is covered by ground moraine cut deeply by the Minnesota River and less deeply by its tributaries. Surface drainage is toward the Minnesota River at the northeast corner of the watershed. The configuration of the water table, generally between 10 and 50 feet below land surface, is a subdued replica of the land surface. Shallow ground water moves generally toward local streams and then into the Minnesota River.

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