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Research about Minnesota

Source-linked reports with geographic coverage including Minnesota.

At least 739 records · Page 41Linked to original sources
USGS1980

Use of solid-state 13C NMR in structural studies of humic acids and humin from Holocene sediments

13 C NMR spectra of solid humic substances in Holocene sediments have been obtained using cross polarization with magic-angle sample spinning techniques. The results demonstrate that this technique holds great promise for structural characterizations of complex macromolecular substances such as humin and humic acids. Quantifiable distinctions can be made between structural features of aquatic and terrestrial humic substances. The aliphatic carbons of the humic substances are dominant components suggestive of input from lipid-like materials. An interesting resemblance is also noted between terrestrial humic acid and humin spectra.

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USGS1980

Ground-water appraisal of sand plains in Benton, Sherburne, Stearns, and Wright counties, central Minnesota

Surficial-sand aquifers in 960 square miles of central Minnesota have been studied to determine the occurrence, availability, and suitability of the surficial aquifer as a source of water. The aquifer is being increasingly developed for irrigation. During the drought of 1976, nearly 24,000 acre-feet of ground water was withdrawn for irrigation, more than double that of the previous year. The number of irrigation pumping centers more than doubled from 1975 to 1977. Nearly all water is pumped from drift aquifers, except in the eastern parts of Sherburne and Wright Counties, where Paleozoic sandstone beds are a reliable source. Physical and hydrologic properties of the surficial aquifer were determined by test augering, pumping tests, and laboratory sieve analyses. The aquifer is predominantly medium to coarse sand with lesser amounts of gravel in much of the study area. The Sauk River valley in Stearns County is nearly 50 percent poorly sorted gravel of irregular thickness. Saturated thickness of sand in the Maine Prairie area locally exceeds 100 feet, and transmissivity exceeds 40,000 feet squared per day. Similar deposits in Sherburne County exceed 80 feet in thickness, transmissivity exceeds 30,000 feet squared per day, and wells theoretically could yield 2,000 to 3,000 gallons per minute. Theoretical well yields of less than 100 gallons per minute can be expected where saturated thickness is less than 20 feet and transmissivity is less than 5,000 feet squared per day. Pumping tests indicate horizontal to vertical ratios of hydraulic conductivity ranging from 2-27:1. Average annual precipitation is 27 inches, about 8 of which is recharge to the surficial aquifer. Regional ground-water movement is toward the Mississippi River, which transects the area. Tributary streams and lakes act as controls for local flow systems. At extreme low flow in August 1976, mainstem gains in streamflow in the Elk, St. Francis, Sauk, and Mississippi Rivers averaged 0.4, 0.4, 0.2, and 2.5 cubic feet per second per river mile, respectively. Ground water is of the calcium bicarbonate type and is suitable for most uses. Relatively high nitrate and chloride concentrations occur in a heavily irrigated area in Sherburne County. Surficial aquifers in Sherburne County and the Maine Prairie area of Stearns County were simulated by two-dimensional digital ground-water-flow models. Calibration was achieved by matching calculated water-table heads and streamflow gains with observed field values. Aquifer responses to pumping stresses under present and hypothetically expanded development were determined for average and below average recharge conditions. Irrigation withdrawals for 1977 totaling 15.6 cubic feet per second from 96 pumping centers were included in the Sherburne steady-state model. Increasing withdrawals to 52.2 cubic feet per second from 153 pumping centers would lower regional water levels as much as 8 feet within a few years at normal recharge rates. Irrigation withdrawals in 1977, totaling 2.0 cubic feet per second from 19 pumping centers, were included in the Maine Prairie steady-state model. Increasing withdrawals to 10.8 cubic feet per second from 42 pumping centers would lower regional water levels as much as 18 feet at normal recharge rates. Both modeled areas will support additional withdrawals, but caution must be exercised because lowering ground-water levels will also lower lake levels and reduce streamflow. In some areas, aquifer dewatering will reduce individual well yields.

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USGS1980

Hydrologic budget for Eagle Lake near Willmar, Minnesota

Eagle Lake occupies 890 acres of a 9,000-acre watershed in central Minnesota. Because of its proximity to Willmar, many homes and summer cabins have been built around the lake. Presently (1978), the shore is more than 90 percent developed. One effect of this development is accelerated eutrophication, most commonly shown by algae blooms. An annual hydrologic budget for Eagle Lake was prepared for the 1978 water year in support of a nutrient study prepared by the University of Minnesota at Morris. Results show that the amount of water that flowed through Eagle Lake in the 1978 water year was 6,670 acre-feet. Inflow to the lake was 45 percent surface water, 22 percent ground water, and 33 percent precipitation. Outflow was 73 prcent surface water, 25 percent evaporation, and slightly greater than 2 percent net change in lake storage. Estimates for the ground-water component were derived both as a residual in the hydrologic-budget equation and by flow-net analyses. The residual value of 1,450 acre-feet compared favorably with the flow-net value of 1,400 acre-feet.

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USGS1980

Hydrologic setting of Williams Lake, Hubbard County, Minnesota

The hydrology and geology of Williams Lake watershed was studied to evaluate the accuracy of various methods used to determine precipitation and evaporation in lake water-balance studies and to define a lake and ground-water system according to approaches suggested by theoretical modeling studies. Regression analysis between estimated and measured precipitation at the lake showed that the accuracy of regionalization techniques is dependent on the closeness of the data network to the lake. For individual storms, the average-value method was found to be better than either the weighted average or isohyetal methods of determining precipitation, but it was least accurate in estimating 14-day average precipitation. The amount of evaporation calculated by the mass-transfer method ranged from 2 to 7 inches per month from July to October 1978, depending on the method used to determine the mass-transfer coefficient. Test drilling indicated that 30 to 150 feet of sand and gravel overlies till in the Williams Lake watershed. A sand lens about 50 feet thick occurs within the till. The configuration of the water table and vertical-head gradients measured from July to December 1978 indicate that ground water moves into the lake from the south and east and moves from the lake into the ground-water reservoir to the west. Preliminary numerical models indicate that the sand lens within the till is effectively isolated from the flow system interacting with the lake and that both inseepage and outseepage were about 1.4 inches from mid-July to mid-October 1978. When estimated as a residual in a water balance, ground water showed a net outseepage only of 1.47 inches.

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USGS1980

Ground-water appraisal in northwestern Big Stone County, west-central Minnesota

The development of ground water for irrigation in northwestern Big Stone County has not kept up with development in other irrigable areas of the State. This is due, in part, to the absence of extensive surficial aquifers and the difficulty in locating buried aquifers. Test augering south of Beardsley outlined a small surficial aquifer that consists of outwash deposits of sand and gravel. The aquifer is elongate, trending northeast-southwest, with a maximum saturated thickness of 42 feet and an areal extent of about 5 square miles. Deep test drilling showed that small buried outwash aquifers occur over much of the project area. The 2-mile spacing between test holes, however, was too great to permit correlation of the buried aquifers. A major buried outwash aquifer, east of Beardsley, consists of 130 feet of fine, uniform quartz sand, The aquifer lies in a steep-sided northwest-southeast trending valley eroded in bedrock and is overlain by 130 feet of clayey till. Pumping-test results indicate that its transmissivity ranges from 10,800 to 13,400 feet squared per day, and that the storage coefficient ranges from 0.0001 to 0.002. Recharge to the aquifer was negligible during 1979. Two Cretaceous aquifers, the Codell Sandstone Member of the Carlile Shale and the Greenhorn Formation, underlie the area, but little is known about these aquifers. Samples of water were collected for chemical analysis from wells in the surficial outwash, buried outwash, and Cretaceous aquifers. With the exception of nitrate, the greatest difference in chemical quality was between samples from the buried outwash and Cretaceous aquifers. Water from Cretaceous aquifers is softer than water from the outwash aquifers, but contains concentrations of sodium and boron that are high enough to damage soils and crops if used for irrigation. Nitrate concentrations exceeded the Minnesota Pollution Control Agency's recommended limits for drinking water in one sample from the surficial aquifer.

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USGS1980

Quality of runoff from small watersheds in the Twin Cities Metropolitan Area, Minnesota - A project plan

A program of water-quality sampling to define the relationships between land use, watershed characteristics, and the quantity, quality, and timing of runoff has been started for the Twin Cities metropolitan area of Minnesota. Ten major watersheds were chosen as representative of conditions in the metropolitan area. Each will be sampled at one location near the outlet. Six of the watersheds are agricultural and range in size from 14.3 to 82.9 square miles. The four remaining watersheds are urbanized and range in size from 1.22 to 31.7 square miles. In addition, seven urban subwatersheds, which range in size from 0.12 to 0.47 square miles and reflect a dominant land-use type, will be sampled. Data collection is designed around the hydrologic conditions expected for each site. Sixteen of 17 sites are instrumented to define stream discharge, and 12 sites have automatic water samplers and recording rain gages. In addition, six sites will have automatic wetfall/dryfall precipitation collectors. Samples for analysis of 32 chemical, physical, and biological constituents will be collected at varying frequencies, with emphasis on storm sampling for suspended solids and nutrients. A data-management system being designed for the U.S. Geological Survey Urban Hydrology Studies Program will facilitate data processing. Data interpretation will be aimed at defining the quantity and quality characteristics of runoff from study watersheds. These findings will be extrapolated to unsampled watersheds in the metropolitan area.

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USGS1980

Hydrology and water quality of the copper-nickel study region, northeastern Minnesota

Data were collected on the hydrology of the Copper-Nickel study region to identify the location and nature of groundwater resources, determine the flow characteristics and general quality of the major streams, and determine the potential effects of mining copper and nickel on the hydrologic stream. Groundwater generally occurs in local flow systems within surficial deposits and in fractures in the upper few hundred feet of bedrock. Yields commonly range from 1 to 5 gallons per minute from wells in surficial materials and bedrock, but can be as much as 1,000 gallons per minute from wells in the sand and gravel aquifer underlying the Embarrass River valley. Groundwater generally is calcium-magnesium bicarbonate types. Over a mineralized zone, groundwater has concentrations of copper and nickel greater than 5 micrograms per liter. The average annual runoff from streams in the study area is about 10 inches. About 60% of the annual runoff occurs during snowmelt in spring. Flood peaks are reduced in streams that have surface storage available in on-channel lakes and wetlands. Specific conductance in streams can exceed 250 micromhos per centimeter at 25 Celsius where mine dewatering supplements natural discharge. Estimated groundwater discharge to projected copper-nickel mines ranges from less than 25 to about 2,000 gallons per minute. The introduction of trace metals from future mining activities to the groundwater system can be reduced if tailings basins and stockpiles are located on material which has low permeability, such as till, peat, or bedrock. (USGS)

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USGS1980

Flood-plain areas of the Mississippi River, mile 866.8 to mile 888.0, Minnesota

Profiles of the regional flood, 500-year flood, and flood-protection elevation have been developed for a 21-mile reach of the Mississippi River. Areas flooded by the regional flood and by the 500-year flood were delineated by photogrammetric mapping techniques and are shown on seven large-scale map sheets. Over 1,300 acres of flood plain are included in the cities of Anoka, Champlin, Coon Rapids, Dayton, Ramsey and Elk River, and in unincorporated areas of Wright County. The flood-outline maps and flood profiles comprise data needed by local units of government to adopt, enforce, and administer flood-plain management regulations along the Mississippi River throughout the study reach. Streamflow data from two gaging stations provided the basis for definition of the regional and 500-year floods. Cross-section data obtained at 83 locations were used to develop a digital computer model of the river. Flood elevation and discharge data from the 1965 flood provided a basis for adjusting the computer model. Information relating the history of floods, formation of ice jams, and duration of flood elevations at Anoka and at Elk River are included.

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USGS1980

The Vermilion Granitic Complex — A new name for old rocks in northern Minnesota

The name Vermilion Granitic Complex is introduced for the heterogeneous granitic and migmatitic rocks of Archean (formerly called Precambrian W) age that occur north of the Vermilion district and south of the Kabetogama peninsula in northern Minnesota. The complex consists of the following subdivisions: Lac La Croix Granite, granite-rich migmatite, schist-rich migmatite, quartz-feldspar gneiss, hornblende quartz diorite and diorite, granodiorite and trondhjemite, amphibolite and amphibolite migmatite, older migmatite, biotite schist, Burntside Gneiss, and pegmatite. Because the name Vermilion Granitic Complex is proposed as a more inclusive group term, the more restricted name Vermilion Granite (Grout, 1923) is hereby abandoned. The new name Lac La Croix Granite is proposed for the uniform, light-pink biotite granite that occurs widely in the eastern and central parts of the complex. It is denned as having less than 5 percent of schistose or gneissic inclusions and is therefore more restricted than the Vermilion Granite of Grout (1926), which included substantial amounts of migmatitic rocks. The name Burntside Gneiss is adopted as a replacement for the older term Burntside Granite Gneiss, originally named by Grout (1926). This change is required by the conclusion that the rock is a metamorphosed dacite and not a metamorphosed granite, as formerly interpreted.

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USGS1980

Baseline water quality of Schmidt, Hornbeam, and Horseshoe Lakes, Dakota County, Minnesota

Three lakes in Dakota County were sampled five times during an 18-month period to determine baseline water quality prior to construction of an interstate highway. Results of physical measurements and chemical analyses showed that the lakes were shallow, nonstratified, and nutrient enriched. Considerable seasonal variations in dissolved solids, nutrient, and dissolved-oxygen concentrations were observed. Oxygen depletion and high nutrient concentrations were characteristics of conditions under an ice cover. Blue-green algal blooms typically were established soon after ice breakup and persisted until late fall. Data from the study will be supplemented with data--collected during and after construction of the highway to assess the impact of highway construction s \d drainage on water quality of the lakes.

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USGS1980

Water quality of Rogers Lake, Dakota County, Minnesota

Construction of an interstate highway is planned near Rogers Lake in Dakota County, Minn. Samples of water and bed material were collected at six sites during March 1976 to April 1978 to determine selected physical, chemical, and biological characteristics before construction. Samples were collected at least twice during each season of the year. Data derived from these samples will provide baseline information to aid in assessing the impact of highway construction on the water quality of the lake. Rogers Lake is separated into an upper and lower lake by a culvert; both were eutrophic and dominated by blue-green algae year around. Analyses of water from Rogers Lake suggest that sodium and chloride concentrations were higher than in ground water or in water in some surrounding lakes . Sodium ranged from 7.2 to 55 milligrams per liter, and chloride ranged from 15 to 30 milligrams per liter. Concentrations were highest in March 1978, when most of the lake water was frozen. Much of the sodium and chloride may have been derived from road salts used for deicing.

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USGS1980

Water quality of four lakes in Lakeville, Minnesota

Water-quality characteristics were determined for four selected lakes to provide background data for evaluating changes that may occur in the lakes because of urbanization. Precipitation of calcium carbonate is suggested by high pH values and a decrease in the calcium concentration when magnesium, sodium, and chloride concentrations increase. Pollution is indicated by chloride concentrations that increased from 18 to 57 milligrams per liter in 1978. The eutrophic state of the lakes is suggested by dissolved oxygen supersaturated near the surface and less than 0.1 milligram per liter near the deepest parts of the lakes. Determination of the trophic state of the lakes provided trophic state indices as high as 69-2. Phosphorus concentrations were significantly higher in two of the lakes sampled. Anacystic and Oscillatoria were the dominant phytoplankton genera. Phytoplankton blooms occurred throughout the year with the highest sampled concentration yielding 890,000 cells per milliliter.

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USGS1980

Effects of urbanization on the water quality of lakes in Eagan, Minnesota

Water-quality characteristics of 17 lakes and ponds in the city of Eagan were described from data collected from 1972 through 1978. The data showed that differences in water quality between lakes were related to differences in the percentage of urbanization. However, water-quality variations within each lake were affected more by climatic variations than by land-use changes during that period. Dissolved solids, alkalinity, and chloride concentrations varied most in lakes with urbanized watersheds, in lakes with outlets, and in lakes less than 6 feet deep. Certain lakes without outlets showed an increase in chloride during the study, caused in part by urbanization but intensified by drought conditions of 1976-77. Fifteen of the lakes studied are less than 10 feet deep and frequently mix during open water. These lakes are highly eutrophic, primarily because of high nutrient loading and recycling of nutrients. Holland and Fish Lakes, with depths of 52 and 30 feet, respectively, were the least eutrophic. These lakes limit continuous recycling of nutrients from bottom materials to water surface by thermal stratification and entrapment of nutrients in the hypolimnion. Three phosphorus-prediction models developed during the study are applicable to shallow (less than about 12 feet), nonstratifying lakes and ponds. The data base was not sufficient to select an appropriate model to predict the effects of future loading from continuing urbanization on the deeper lakes.

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USGS1980

Preimpoundment water quality of the Wild Rice River, Norman County, Minnesota

Water samples have been collected at two sites on the Wild Rice River since September 1974 to establish baseline water-quality characteristics before construction of a reservoir for recreation and flood control near Twin Valley, Minn. A decline in water quality between the sites is shown by mean total phosphorus concentrations, which increase from 0.06 to 0.10 milligram per liter downstream, and mean turbidity, which increases from 12 to 24 units downstream. Phosphorus and ammonia concentrations, as high as 0.31 and 2.7 milligrams per liter, respectively, could be the result of domestic waste input to the river upstream from Hendrum. Biochemical oxygen demand concentrations were significantly higher during spring runoff than during the rest of the year. Four out of 90 bacteria samples taken at Twin Valley indicate the presence of human fecal material, though bacteria densities do not exceed recommendations of the U.S. Environmental Protection Agency for public-water supplies. The dominace of organic-pollution tolerant phytoplankton in 49 out of 78 samples also indicates degradation of the river quality at Twin Valley. Nutrient concentrations at Twin Valley have no apparent effect on phytoplankton concentrations. None of the consitituents sampled were found to exceed recommended concentrations for public-water supplies.

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USGS1979

An improved method of censusing deer in deciduous-coniferous forests

Aerial censusing has been used to determine densities of many large mammals, including deer ( Odocoileus virginianus ) in agricultural areas or deciduous forests (Saugstad 1942, Morse 1946, Petrides 1953, Sanderson 1953, Berner pers. comm.). However, observability of deer from the air remains a problem in northern coniferous forests. LeResche and Rausch (1974) determined that even with the much larger and more observable moose ( Alces alces ) during ideal snow conditions, experienced observers counted only 68% of a known number of animals; inexperienced observers counted 43%. Caughley (1974) and Caughley et al. (1976) suggested that the best solution to the problem of observability in aerial censuses is to measure the magnitude of the biases that exist, and correct estimates accordingly. This paper describes an attempt to measure observability bias in an aerial census of deer in deciduous coniferous habitat and to produce an accurate estimate of numbers.

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