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Research about Minnesota

Source-linked reports with geographic coverage including Minnesota.

At least 829 records · Page 46Linked to original sources
USGS1974

Water resources of the Crow River watershed, south-central Minnesota

The Crow River watershed, an area of about 2,760 square miles, is covered entirely by glacial deposits. A topographically high, east-west-trending end moraine divides most of the watershed into two drainage areas of approximately equal size. The North Fork Crow River drains a mixture of glacial outwash and till deposits, whereas the South Fork Crow River drains chiefly till deposits. Local relief is greatest in morainal areas and least in surficial outwash areas. Cambrian and Precambrian sedimentary rocks underlie the glacial drift in the eastern part of the watershed. Cretaceous sedimentary rocks, though discontinuous, are present in part of the western two-thirds of the watershed. Where sedimentary bedrock is absent, the glacial drift is directly underlain by Precambrian igneous or metamorphic rocks. Forested areas are sparse and occur mainly in steeply sloping morainal areas. Most land is used for agriculture, and slightly more than half the total population is rural.

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USGS1974

Hydrologic Unit Map -- 1974, Minnesota

This map and accompanying table show Hydrologic Units that are basically hydrographic in nature. The Cataloging Units shown will supplant the Cataloging Units previously used by the U.S. Geological Survey in its Catalog of Information on Water Data (1966-72).

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USGS1974

Earthquake history of Minnesota

French traders and missionaries were active in the region that is now Minnesota as early as the 1650's; however, settlement proceeded slowly and the area was not organized as a territory until 1849. Minnesota was admitted to the Union as the 32nd State on May 11, 1858. the earthquake history of the State is incomplete, owing to the scarity of residents prior to the middle of the 19th century.

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USGS1973

Analysis of radiotracking data using digitized habitat maps

A method is described that provides a rapid and accurate analysis of habitat used by radio-equipped animals. The digitizer (basically an X-Y plotter in reverse) converts maps into digital form by describing each habitat unit as a polygon that closely approximates the actual shape of the unit. The coordinates of each polygon are then stored on magnetic tape. Habitat classification data and other information are coded and combined with the proper polygon coordinates. This results in one file containing all habitat data. A computer program with inputs of tracking data and habitat data provides a listing of the habitat used by the animals studied. Analysis of habitat used by radio-equipped ducks is demonstrated using this method.

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USGS1973

Petrography and stratigraphy of glacial drift, Mesabi-Vermilion Iron Range area, northeastern Minnesota

Glacial deposits in the Mesabi-Vermilion Iron Range area consist of four major till units and associated glaciofluvial sediments. Particle-size data and pebble, heavy-mineral, clay-mineral, and percentage-soluble content were used in addition to field description of color and texture to describe and correlate the drift units. The lowermost till unit, basal till, occurs in only a small number of mines, but the mines are scattered across the entire Iron Range. The till is dark gray to dark greenish gray and brownish gray, sandy, silty, and calcareous. Pebbles are largely granitic and metamorphic rocks of local origin, but include limestone, dolomite, shale, basalt, felsite, agate, and gabbro. Clay-mineral content is largely illite. The age of the till is probably middle or early Wisconsin but could be pre-Wisconsin. The middle till unit, bouldery till, is the thickest and most widespread of the four tills. It is gray, yellow, red, orange, or brown, sandy, silty, noncalcareous and contains abundant cobbles and boulders. Pebbles are largely granitic and metamorphic rocks of local origin, but also include gabbro, basalt, and felsite in minor amounts. Montmorillonite is the most common clay mineral. Colored bouldery till below gray bouldery till may be a separate subunit distinguished largely on particle-size differences, but the overall characteristics are similar to the other bouldery till. The till was deposited by the Rainy lobe, which has a minimum age of 14,000 to 16,000 years before present. The uppermost, or surficial, tills were deposited contemporaneously by two minor sublobes of the Des Moines lobe about 12,000 years ago. Brown silty till occurs in the western and north-central part of the study area. It is light to medium brown, sandy, silty, and calcareous. Pebbles are largely granitic and metamorphic rocks of local origin, but include limestone, dolomite, shale, basalt, felsite, and gabbro. Clay-mineral content is largely mixed-layered montmorillonite and illite. Red clayey till occurs in the south-central part of the area. It is red to reddish brown, clayey, silty, and calcareous. Pebbles are similar to those in the brown silty till, but contain less limestone than the brown till. Glaciofluvial sediments are common between the various till units throughout the area, but are thickest near the east and near the west ends of the Iron Range.

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USGS1973

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

The topography of the Kettle River watershed is formed primarily by glacial deposits that mantle the bedrock. The glacial deposits are generally less than 100 feet thick. Bedrock consists of several types and occasionally crops out at land surface. Topography ranges from gently rolling to steeply undulating. About 1,060 square miles is drained by the Kettle River and its tributaries, and about 510 square miles by smaller streams that are direct tributaries to the St. Croix River. Peat and swamp areas are common, particularly in the eastern part of the area. Most of the watershed is forested, mainly with hardwoods.

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USGS1973

Water resources outlook for the Minneapolis-Saint Paul Metropolitan Area, Minnesota

The water resources were studied within an area whose natural ground-water flow is largely towards the center of the metropolitan area. This area coincides with the extent of the Hinckley Sandstone aquifer. Thus, the general geohydrology of the area bounded by the extent of the Hinckley Sandstone (about 6,000 square miles) as it relates to the hydrology of the Minneapolis-St. Paul metropolitan area is described. Greater emphasis is placed on the area underlain by the Prairie du Chien-Jordan aquifer (about 2,000 square miles), from which approximately 75 percent of the ground-water for the metropolitan area is pumped. The study indicates that the surface-water resources of the Twin Cities metropolitan area are used to such an extent that a supply adequate for domestic and industrial needs as well as power plant and sanitary effluent assimilation will not be available during severe drought. Ground-water is obtained primarily from two aquifer systems: The Prairie du Chien-Jordan and the Mount Simon-Hinckley. In 1970, these aquifers supplied about 90 percent (175 mgd) of the ground-water used in the metropolitan part of the study area. The probable level of development that can be sustained by these two aquifers in the metropolitan area is estimated to be 1,100 mgd; thus, substantial additional ground-water supplies could be developed. However, considerable management and planning would be needed to sustain this level of development. Maps in this report can be used to select general well-field locations based on consideration of 1) aquifer, 2) depth needed for completion, 3) head availability, 4) location of natural recharge and discharge boundaries, and 5) distance from areas where over-development of ground-water resources is imminent. Because of complexities in the ground-water system, yield estimates, boundary effects, and effects of aquifer interaction may best be determined in a study incorporating the use of a hydrologic model. Future detailed studies might include elaboration on some of the topics described in this report and the acquisition and interpretation of new data. Major items on which future work might focus are 1) data collection, 2) geohydrologic mapping, 3) hydraulic characteristics of subsurface geohydrologic units, 4) hydrology of lakes, and 5) hydrologic systems modeling

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USGS1973

Appraisal of ground water for irrigation in the Little Falls area, Morrison County, Minnesota

Anticipated irrigation on sandy soils has prompted evaluation of ground-water supply potential in the Little Falls area. Geologic conditions cause ground-water availability to vary widely in the area. The largest and most readily available groundwater source is the glacial outwash sand and gravel from which the soils were derived. Test augering shows that the saturated surficial outwash is as much as 50-100 feet thick in the area where the outwash fills a probable former meltwater channel and that it is also this thick in smaller areas elsewhere. Transmissivity of the thicker parts of the aquifer approaches or exceeds 100,000 gallons per day per foot, and probable well yields should exceed 1,000 gallons per minute. In about two-thirds of the study area, a saturated thickness of less than 40 feet generally limits well yields to less than 300 gallons per minute. Recharge to the surficial aquifer is obtained primarily from precipitation. Most discharge occurs as evapotranspiration, base flow to the Mississippi River, and base flow to other streams and to lakes. Possible future response to pumping was studied through electric analog analyses by stressing the modeled aquifer system in accordance with areal variations in expected well yields. The model interpretation indicates most of the sustained pumpage would be obtained from intercepted base flow and evapotranspiration. Simulated withdrawals totaling 18,000 acre-feet of water per year for 10 years resulted in little adverse effect on the aquifer system. Simulated larger withdrawals, assumed to represent denser well spacing, caused greater depletion of aquifer storage, streamflow, and lake volumes, excessively so in some areas. Results of model analyses provide a guide for ground-water development by identifying the capability of all parts of the aquifer system to support sustained pumping for irrigation.

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USGS1973

Hydrogeology of glacial drift, Mesabi Iron Range, northeastern Minnesota

Stratified fluvial sediments occur within the glacial drift at many places in the Mesabi Iron Range area. These sediments, which are important aquifers, occur extensively between the three main till units. The thickest and most extensive aquifer consists of glaciofluvial sediments that lie between the surficial till and the middle till unit, the bouldery till. Thickness of the glaciofluvial sediments at this stratigraphic interval is greater than 50 feet in much of the area, and transmissivity is greater than 100,000 gallons per day per foot in some places. Glaciofluvial sediments underlying the bouldery till occur largely in the western half of the area. These sediments are generally less than 50 feet thick, and transmissivity is generally less than 50,000 gallons per day per foot. Surficial glaciofluvial sediments are a source of ground water for high-yield wells only in the eastern part of the area in the vicinity of the Biwabik bedrock valley. Thickness of these sediments is greater than 100 feet in some places, but transmissivity is generally less than 50,000 gallons per day per foot. Practical sustained yield of aquifers in glacial drift is estimated to be as much as 40 million gallons per day from known aquifers. Assuming that the ratio of area underlain by aquifer to total area is constant for the study area (about 20 percent where mapped in detail), as much as 80 million gallons per day could be developed from glacial-drift aquifers.

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USGS1972

Red fox spatial characteristics in relation to waterfowl predation

Radio-equipped red foxes ( Vulpes vulpes ) on the Cedar Creek area in Minnesota were spatially distributed, with individual families occupying well defined, nonoverlapping, contiguous territories. Territory boundaries often conformed to natural physical boundaries and appeared to be maintained through some nonaggressive behavior mechanism. Individual foxes traveled extensively throughout the family territory each night. Fox territories appeared to range from approximately 1 to 3 square miles in size, dependent largely on population density. Red foxes used a sequence of dens to rear their pups, and the amount and location of food remains at individual dens changed as the pups matured. The denning season was divided into pre-emergence, confined-use, and dispersed-use periods of 4 to 5 weeks each. Remains of adult waterfowl were collected at rearing dens on six townships in three ecologically different regions of eastern North Dakota. Remains of 172 adult dabbling ducks and 16 adult American coots (Fulica americana) were found at 35 dens. No remains from diving ducks were found. The number of adult ducks per den averaged 1.6, 5.9, and 10.2 for paired townships in regions with relatively low, moderate and high duck populations, respectively. Eighty-four percent of the ducks were females. The species and sex composition of ducks found at dens during early and late sampling periods reflected the nesting chronology of prairie dabbling ducks. Occupied rearing dens were focal points of red fox travel, and the locations of dens may have had considerable influence on predation. Thirty-five of 38 dens found on the six township study areas were on pastured or idle lands. The distribution of rearing dens on the Sand Lake and Arrowwood national wildlife refuges suggested that, on these areas, fox dens were concentrated because of the topography and land-use practices.

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