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Source-linked reports with geographic coverage including Minnesota.

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USGS1965

Hydrology of melt-water channels in southwestern Minnesota

Melt-water channel deposits are among the most important aquifers in southwestern Minnesota, but permeable zones within the deposits are difficult to locate. Interpretation of the depositional history of proglacial channel deposits from aerial photographs and test-hole samples indicates the position of the permeable zones. Generally, the coarse-grained deposits are in headwater areas, near the confluence of two channels, in bends, or at the junction of sluiceways. Locally, these deposits yield as much as 1,000 gallons per minute to wells.

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USGS1964

Bedrock topography of the eastern and central Mesabi Range, northeastern Minnesota

The Mesabi iron-mining district or range, is in north-eastern Minnesota, 60 to 85 miles west of Lake Superior. The Mesabi Range, in this report, includes the iron-mining belt, ¼ of a mile to 3 miles wide, that extends for 120 miles in a northeasterly direction across Itasca and St. Louis Counties. It is the area of economically important iron-bearing formation and associated rocks, now mostly buried under glacial drift.

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USGS1964

Geology and ground-water conditions of the Redwood Falls area, Redwood County, Minnesota

The Redwood Falls area includes about 80 square miles in southwestern Minnesota and is about 100 miles west of Minneapolis and St. Paul. Its surface is a gently undulating glacial-drift plain, interrupted in part by the large Minnesota River valley and the tributary Redwood River valley. The drift plain was laid down by the Des Moines lobe of the Wisconsin Glaciation and consists chiefly of ground moraine and several subdued recessional moraines. The glacial drift rests either on Precambrian gneiss or on thin patches of Cretaceous sedimentary strata that overlie the Precambrian bedrock. The glacial drift consists principally of till and some outwash and ranges in thickness from 0 to about 260 feet. It is the chief source of ground water, yielding small supplies almost anywhere in the area and large supplies in at least two places. Where the drift is absent, thin, or impermeable, small yields commonly are obtained from the Precambrian bedrock. The most notable aquifers in the area are three buried outwash deposits that are associated with a conspicuous southeastward-trending buried bedrock valley. The tops of the aquifers occur about 70,120, and 200 feet below the land surface, and their maximum known thicknesses are about 25, 55, and 45 feet, respectively. The aquifers are confined largely by relatively impermeable till; however, owing to the movement of water through the till, the drift may be regarded as a hydraulic unit. The main source of recharge to the ground-water reservoir is local precipitation, and most of the natural discharge is by evapotranspiration. The water table ranges in depth from 0 to about 30 feet below the land surface. Aquifer tests were made on the three outwash aquifers to determine their hydraulic characteristics. The coefficient of transmissibility (T) of the 200-foot aquifer is about 126,000 gpd (gallons per day) per ft, and the coefficient of storage (8) is about 0.0002. The T and S values of the 120-foot aquifer are about the same as for the 200-foot aquifer. For the 70-foot aquifer the value of T is about 70,000 gpd per ft, and S is about 0.0007. The data suggest that when the artesian head in the aquifers is lowered by pumping, recharge is induced by leakage from the confining beds. The 120-foot aquifer is considered the best known source of ground water In the area. The city of Redwood Falls has used this aquifer for its water supply since August 1955 and, in 1960, pumped about 106 million gallons from it. The water level in the aquifer had stabilized by late 1956; considerable additional water probably can be obtained from the aquifer. Although the 70-foot aquifer is not as extensive or as thick as the one at 120 feet, large amounts of water probably can be obtained from this aquifer also. The 200-foot aquifer is narrow, elongate, and irregular in form and appears to be very permeable only locally. Chemical analyses show that water from the glacial-drift aquifers is primarily of the bicarbonate type, is hard, and contains an excessive amount of iron. In places water from the Precambrian bedrock is much softer than water from the drift.

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USGS1964

Geology and ground-water resources of Nobles County, and part of Jackson County, Minnesota

The area described in this report is in southwestern Minnesota, about 130 miles southwest of Minneapolis and St. Paul. It includes; Nobles County and the western tier of townships in Jackson County, a total of 864 square miles. Worthington, the Nobles County seat, is the largest city in the area, having a population of 9,015 persons (1960 census). Farming is the leading occupation, and food processing is the major industry. Critical water shortages have occurred in several parts of the area. The climate is characterized by mild, subhumid summers and relatively long, severe winters. Mean monthly temperatures range from 15.1 °F in January to 73.3 °F in July. The mean annual precipitation is 26.75 inches. The crest of the Coteau des Prairies, a broad highland belt, traverses Nobles County from northwest to southeast. Three glacial end moraines and their associated ground moraines trend south to southeast across the area. Altitudes range from about 1,820 feet on the crest of the coteau in the northwestern part of the area to about 1,390 feet above mean sea level in the Jack and Okabena Creek valleys in the northeast. The Mississippi-Missouri River drainage divide crosses the area from north to east. The Gary outer end moraine trends southeast through central Nobles County. East of this moraine the land is poorly drained and contains numerous lakes and swamps; west of this moraine the land is well drained and contains few, if any, undrained depressions. Within the area, granite and Sioux Quartzite of Precambrian age are overlain by Cretaceous strata, except locally in the northeast and northwest parts of the area where the quartzite is directly overlain by glacial drift. The Cretaceous strata are composed of interbedded shale, siltstone, and sandstone. The surface of the area is composed of Pleistocene deposits of glacial drift and some thin, patchy deposits of Recent age. Bedrock is not known to crop out in the area. The drift ranges in thickness from about 150 feet in the southwest and northeast corners to about 500 feet on the highest part of the Coteau des Prairies. The Precambrian granite is not a source of ground water in this area. The Sioux Quartzite yields moderate supplies in adjacent counties to the north and west, but because of its sporadic occurrence it does not constitute an important water source in this area. The Cretaceous sandstone units are a secondary source of ground water and yield adequate supplies 'to at least 24 farm wells, which range in depth from 283 to 586 feet below land surface. The primary source of ground water in the Nobles-Jackson County area is the glacial drift. Buried outwash deposits supply water to 7 of the 10 municipalities and to most of the farms in the area. Two Worthington city wells, completed in a buried outwash deposit underlying East Okabena dry lake bed, were tested for short periods at 500 gallons per minute. The estimated coefficient of transmissibility for the aquifer at one of the wells was 70,000 gpd (gallons per day) per ft. The buried outwash deposits may occur anywhere within the drift from about 15 feet below land surface to bedrock which is as much as 500 feet below land surface. The outwash ranges from a fraction of a foot to more than 25 feet in thickness where permeable; below the water table it generally will supply ample quantities of water to properly constructed wells. Surflcial outwash deposits fill the valley bottoms and form the terrace deposits associated with the present-day drainage channels. The thicker, more extensive, and continuous deposits occur in the proglacial stream channels that drained the fronts of the ice sheets rather than in those channels that now drain the backs of the moraines. The surflcial outwash deposits generally are made up of sand, gravel and some silt and clay, and range in thickness from 0 to more than 60 feet; they range in width from a few feet in the narrow tributaries to about one mile in the larger stream valleys. Four municipalities and many farms obtain part or all of their water supplies from surficial outwash. An Adrian municipal well, completed in this source, was pumped at a rate of 400 gpm. At the confluence of two streams which drain Ocheda Lake in southeastern Nobles County, the sand and gravel section is more than 60 feet thick in places. Results of a pumping test here showed an average coefficient of transmissibility of 150,000 gpd per ft. Coefficients of transmissibility may be as much as 500,000 gdp per ft in the thickest part of the deposit if the permeability of the sand and gravel is uniform. Recharge to the surflcial outwash deposits is relatively rapid; it is slower to the buried outwash deposits where the descending water must percolate through till of low permeability before entering the aquifers. The quality of water in the Precambrian crystalline rocks, the Cretaceous strata, and the buried Pleistocene aquifers is poor. Chemical analyses of 22 water samples showed that dissolved solids ranged from 1,100 ppm (parts per million) to 3,050 ppm. Water from the surficial outwash deposits is good by comparison; dissolved solids in water from these aquifers ranged from 425 to 870 ppm.

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USGS1963

Two pollen diagrams from southeastern Minnesota: Problems in the regional late-glacial and postglacial vegetational history

Kirchner Marsh and Lake Carlson are located 3 miles apart in Dakota County about 15 miles south of Minneapolis in the St. Croix moraine, which was formed by the Superior lobe during the Gary phase of the Wisconsin glaciation. During the Mankato phase that followed, the Des Moines lobe advanced to within a few miles of the sites. The region today is in a mixed-oak forest, with a maplebasswood forest 15 miles to the west and a re-entrant of the prairie on the sand plain south of the moraine. The general limit of coniferous trees is about 50 miles northeast of the sites, although outliers, especially of Pinus strobus, may be found along the Mississippi Valley a few miles to the east. One sediment core 12-13 m long from each site was analyzed for pollen content at 5-25-cm intervals. Diagrams based on percentage of total pollen (trees, shrubs, wind-pollinated herbs) show essentially identical sequences at the two sites, starting with the late-glacial phase of ice retreat. The diagrams have been subdivided into pollen zones according to the A-B-C sequence introduced by Deevey for New England. The late-glacial pollen record starts at Kirchner Marsh with a short Picea-Cyperaceae-Gramineae phase (Zone K), believed to represent a spruce parkland. Its C-14 date of 13,270 BP and the stratigraphy indicate a pre- Two Creeks and post- Gary correlation. Apparently the Kirchner site did not become established as a lake until this time owing to persistence of dead ice in the moraine. The absence of pollen of specific tundra indicators and the presence of pollen of such thermophilous plants as Fraxinus, Quercus, Corylus, Ambrosia, Humulus, and Typha latifolia imply that the climate was cool rather than cold. Zone A-a, which follows, correlates with the Two Creeks interstade. It is marked by the dominance of Picea, with appreciable percentages of Fraxinus and Ambrosia and with minor amounts of other thermophilous plants and the normal boreal associates of spruce like Betula, Larix, and Salix. Zone A-b, starting 12,050 C-14 years ago, correlates with the Valders ice advance. It is represented at both Kirchner and Carlson and shows the withdrawal of Fraxinus and Ambrosia and the slight rise of Artemisia. Except for the absence of pine in the late-glacial assemblage the vegetation implied by these three zones seems to have its closest modern counterpart in the southern fringe of the Boreal Forest of the Riding Mountain region of southwest Manitoba. It is concluded that pine did not migrate southward with the spruce during the Wisconsin glaciation, at least in the western Great Lakes region, and was thus eliminated from this region. During the lateglacial phases of ice retreat, herbs and spruce pioneered on the deglaciated terrain; pine did not follow until the destruction of the spruce forest at the end of the late-glacial phase. Zone B introduces postglacial time. It represents the time of rapid Vegetational succession following the deterioration of the spruce forest. Simultaneous maxima of Betula, Alnus, Fraxinus, and Abies occurred 10,230 years ago at Kirchner Marsh. These were followed rapidly by a Pinus maximum and then a rise of Ulmus, Quercus, and other deciduous types, dated as 9300 years ago at the correlative site of Madeha. This succession may represent differential rates of migration from refuges south and east of Minnesota . Deciduous trees dominate the C Zones. Zone C-a shows Ulmus and Ostrya /Carpinus followed by Quercus; it probably represents principally a mesic maple-basswood forest changing to oak. Zone C-b represents the advance of prairie into the region at the expense of the oak woodland or savanna. The large and abrupt fluctuations in the curves for Ambrosia-type and Chenopodiineae, especially at the Carlson site, may record encroachment of annual weeds onto intermittently dried lake bottoms. C-14 dates place Zone C-b between 7100 and 5100 years ago. In Zone C-c the Quercus again dominates until the abrupt increase in Ambrosiatype and Chenopodiineae that marks the time of forest clearance and land settlement 50-75 years ago.

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USGS1963

Geology and hydrology of the Elk River, Minnesota, nuclear-reactor site

The Elk River, Minn., nuclear-reactor site is on the east bluff of the Mississippi River about 35 miles northwest of Minneapolis and St. Paul. The area is underlain by about 70 to 180 feet of glacial drift, including at the top as much as 120 feet of outwash deposits (valley train) of the glacial Mississippi River. The underlying Cambrian bedrock consists of marine sedimentary formations including artesian sandstone aquifers. A hypothetically spilled liquid at the reactor site could follow one or both of two courses, thus: (1) It could flow over the land surface and through an artificial drainage system to the river in a matter of minutes; (2) part or nearly all of it could seep downward to the water table and then move laterally to the river. The time required might range from a few weeks to a year, or perhaps more. The St. Paul and Minneapolis water-supply intakes, 21 and 25 miles downstream, respectively, are the most critical points to be considered in the event of an accidental spill. Based on streamflow and velocity data for the Mississippi River near Anoka, the time required for the maximum concentration of a contaminant to travel from the reactor site to the St. Paul intake was computed to be about 8 hours, at the median annual maximum daily discharge. For this discharge, the maximum concentration at the intake would be about 0.0026 microcurie per cubic foot for the release of 1 curie of activity into the river near the reactor site.

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USGS1963

Ground-water exploration and test pumping in the Halma-Lake Bronson area, Kittson County, Minnesota

The Halma-Lake Bronson area covers about 80 square miles in the northwestern corner of Minnesota. It is a relatively featureless poorly drained glacial drift plain which slopes gently to the west about 10 feet per mile. The plain is interrupted by sand dunes and by beach deposits of Glacial Lake Agassiz. In the northeastern part of the area, the glacial drift rests on Preeambrian crystalline basement rock; throughout the rest of the area the drift is underlain by shale, limestone, and sandstone of Ordovician age, and probably by shale and limestone of Cretaceous age. Information from 75 test holes showed that, except for minor amounts of surficial swamp sediments, eolian sand, and alluvium, the area is underlain by a'bout 320 to 420 feet of glacial drift. The most important aquifers are the relatively coarse-grained glacial outwash deposits that constitute part of the drift. The principal aquifer is a series of outwash deposits, ranging in thickness from 0 to about 280 feet, that fill a north-south trending valley cut in the underlying relatively impermeable drift. The deposits in this buried valley have an average thickness of about 130 feet in an area about 8 miles long and 3 miles wide, and are considered as a hydrologic unit. The main source of ground-water recharge is precipitation on the part of the area underlain by the principal series of outwash deposits; evapotranspiration accounts for most of the discharge. The sandy texture of the soil and the flat topography are particularly conducive to recharge, and there is extremely little surface runoff. The average depth to the water table is about 8 feet below land surface. Although the regional slope of the water table is probably to the west, locally the gradient is toward Lake Bronson and South Branch Two Rivers. Pumping tests of the outwash deposits in 2 parts of the buried valley indicate that the average coefficients of transmissibility were about 80,000 gpd per ft and about 50,000 gpd per ft. The field coefficients of permeability were about 800 and 300 gpd per sq ft, respectively. About 65 billion gallons of ground water is estimated to be in storage in the area underlain by the principal aquifer. There are no large ground-water developments in the area. The average depth of farm wells and the few municipal wells is about 25 feet. Chemical analyses of water from the principal aquifer show that the water is primarily of the bicarbonate type. The water is hard, and contains high iron Concentrations. Most wells yield water that is softer and less mineralized than ground water from the adjacent area to the west. Large quantities of water suitable for most industrial purposes are available in the Halma-Lake Bronson area. Yields of 1,000 to 2,000 gpm could probably be obtained from wells located by an adequate program of exploratory drilling and test pumping.

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USGS1963

Geology and occurrence of ground water in Lyon County, Minnesota

Lyon County is in southwestern Minnesota, mostly within the drainage basin of the Minnesota River. The basement rocks in the area consist largely of Precambrian granite and quartzite. These are overlain locally by flat-lying Upper Cretaceous strata composed of thick sections of soft dark-bluish-gray shale and some thin beds of loosely consolidated sandstone. The Cretaceous strata are more than 500 feet thick near the center of the county but gradually pinch out toward the northeast and southwest against the highs of the Precambrian bedrock surface. Glacial drift overlies the Precambrian and Cretaceous rocks and forms the surface of the area. The drift consists largely of till and ranges in thickness from about 10 feet in the north and northeast to approximately 550 feet in the southwest. The most prominent surflcial glacial deposits are five southeast-trending end moraines, two of which are associated with, and parallel to, relatively extensive belts of outwash. Recent deposits averaging less than 20 feet in thickness overlie the glacial drift in stream valleys. The principal aquifers in Lyon County are glacial-melt-water deposits of sand and gravel, and sandstone of Cretaceous age. The underlying Precambrian rocks and the Recent alluvium are of only local importance as water sources. Melt-water deposits composed of stratified clay and silt as well as sand and gravel occur in channels having surficial expression, in buried channels having no direct surface expression, and as small isolated bodies within the till. Well logs of test holes show that the buried melt-water channels are generally parallel to the surflcial channels. However, melt-water deposits are not necessarily confined to the area beneath the surflcial channel but may extend laterally 1 mile or more beyond its limits. Sand and gravel are commonly interbedded with other melt-water materials. They range in thickness from 10 to 75 feet, are usually less than 1 mile in width, and may be as much as 8 miles in length. Although these aquifers are extensive, they underlie less than 10 percent of the county area. In most places, water from the drift is obtained from small isolated bodies of sand and gravel within the till. Water in the glacial drift is usually very hard (more than 500 parts per million) and low in chlorides (less than 50 parts per million). Drift wells generally yield from 2 to 30 gallons per minute; however, in areas where wells tap melt-water-channel deposits, sustained yields of as much as 500 gallons per minute are obtained. The sandstone beds of Cretaceous age occur between the Precambrian bedrock surface and an altitude of 825 feet as a basal sandstone, between altitudes of 890 and 1.020 feet, and between altitudes of 1,050 and 1,160 feet. Water-well data, supplemented by test drilling, show that each of these stratigraphic intervals is developed only in the county. The sandstone beds are of low permeability and are usually less than 2 feet thick, but they may be more than 20 feet thick in places. Water from these aquifers range in quality from soft (less than 60 parts per million) to very hard (more than 500 parts per million) and may contain excessive amounts of chloride (500 to 2,000 parts per million). Wells tapping rocks of Cretaceous age usually yield 2 to 7 gallons per minute, but in areas where the sandstone beds are thicker or hydrologically interrelated with aquifers of other geologic units, yields of as much as 75 gallons per minute have been obtained. Large quantities of ground water are available from melt-water channels in the county. Moderate quantities, adequate for domestic and small industrial needs, are available from many of the small isolated deposits of sand and gravel in the till. Small quantities of ground water, adequate only for domestic supply, generally can be obtained from Cretaceous sandstone.

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USGS1963

Geology and ground-water conditions in the southern part of the Camp Ripley Military Reservation, Morrison County, Minnesota

The southern part of the Camp Ripley Military Reservation, in central Minnesota, includes an area of about 20 square miles. This investigation was conducted to assist the U.S. National Guard Bureau in locating adequate water supplies for expansion and standby needs. Bedrock in the area consists of Precambrian phyllite which is equivalent to the Virginia slate. The area is covered largely by Pleistocene deposits in the form of moraines, ice-contact features, outwash plains, and the valley train of the Mississippi River. Almost all the surface deposits consist of outwash-plain and valley-train sediments that are generally permeable. Test drilling and an electrical-resistivity survey indicate that the post area, in the southeast part of the reservation, is underlain by about 50 to 115 feet of glacial drift. The west side of the post area is underlain by a bedrock valley filled in part by permeable glaciofluvial deposits in which there is a narrow, highly permeable channel deposit of sand and gravel. Aquifers of this type are probably the most important source of ground water in the area, although substantial quantities of water also may be obtained from other types of glacial aquifers. Properly constructed and developed wells tapping the channel deposits should yield 2,000 to 3,000 gallons per minute, or more. Recharge to the aquifers in the reservation is derived from the downward percolation of local precipitation. Most recharge occurs during the spring breakup when accumulated winter snows melt and during the warmer months when the heaviest rains occur. Sufficient water is stored in sands and gravels in the area to support substantial water-supply developments for several years, even without normal recharge. The water is harder than is desirable for domestic uses, and it is relatively highly colored, probably owing to the presence of iron. Otherwise, the water is satisfactory for most domestic purposes as it contains only about 250 parts per million of dissolved solids.

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