Prepared and Published with the Support of COUNTY ATLAS SERIES THE BOARD OF COMMISSIONERS, GOODHUE COUNTY, MINNESOTA, AND ATLAS C-12, PART A MINNESOTA GEOLOGICAL SURVEY THE MINNESOTA DEPARTMENT OF NATURAL RESOURCES, DIVISION OF WATERS Plate 2—Bedrock Geology D.L. Southwick, Director

M STRATIGRAPHIC COLUMN ISSISSIPPI RIVER

EXPLANATION FOR STRATIGRAPHIC COLUMN Hydrostratigraphic Group, Character Natural Ð LITHOLOGY Formation, Lithology DAKOTA CO DAKOTA Csf Gamma Log Miller, R.T., and Delin, G.N., 1993, Field observations, preliminary Compo- Perme-

REFERENCES CITED Member in feet Oolites Series nent ability Increasing count Thickness

model analysis, and aquifer thermal efficiency: U.S. Geological Survey LIMESTONE System or Alexander, C.E., 1990, Anion analysis of selected wells and springs: Map Symbol Low High G Glauconite Oronoco dye trace study: Report to Olmsted County, 101 p. Site Professional Paper 1530-A, 55 p. Prosser Ogp 70 report on file at the Minnesota Pollution Control Agency. Mossler, J.H., 1987, Paleozoic lithostratigraphic nomenclature for DOLOSTONE Ph Phosphate pellets Limestone Alexander, E.C., Jr., Huberty, B.J., and Anderson, K.J., 1991, Final Minnesota: Minnesota Geological Survey Report of Investigations Cummings- SANDY Algal domes; stromatolites Ogc 70- 36, 36 p., 1 pl. (folded insert). Group ville report for Olmsted County dye trace investigations of the Oronoco Galena 75 Runkel, A.C., 1996a, Geologic investigations applicable to ground-water T. 114 N. T. 114 N. Burrows Formation sanitary landfill: Prepared by Donohue and Associates for Olmsted SANDSTONE County. Site report on file at the Minnesota Pollution Control Agency. management, Rochester metropolitan area, Minnesota: Minnesota ÐCig North BEDROCK GEOLOGY 60- Lake Pebbles Decorah Shale Od Barr Engineering Co., 1996, Dakota County groundwater model summary Geological Survey Open-File Report 96-1, 33 p.; 4 oversize pls. on 7 SHALY 65 sheets, scale 1:24,000. Flat-pebble conglomerate report: 90 p. + figs., tbls., and appendices. Site report on file at the Platteville Fm Opl 10-15 ÐCe SILTSTONE Minnesota Pollution Control Agency. Runkel., A.C., 1996b, Bedrock geology of Houston County: Minnesota ÐCmt Cross-bedded (festoon) Glenwood Fm Ogw 5-15 Ph Crain, W.E., 1957, The areal geology of the Red Wing quadrangle: Geological Survey Open-File Report 96-4, technical report, 11 p.; 3 Vermillion By Cross-bedded (planar to St. Peter Minneapolis, University of Minnesota, M.S. thesis, 105 p. oversize pls., scale 1:100,000. Clear SHALE Os PrairieÐCig tangential) MIDDLE ORDOVICIAN Sandstone Sansome , C.J., 1986, Origin and configuration of the present-day land Lake Delin G.N., and Woodward, D.G., 1985, Hydrogeologic setting and the A' Vugs (commonly filled with 100-115 surface, Goodhue County, Minnesota: Corvallis, Oregon State Anthony C. Runkel Hummocky cross-strata potentiometric surfaces of regional aquifers in the Hollandale coarse calcite) Ð Sturgeon Embayment, southeastern Minnesota, 1970–80: U.S. Geological Survey University, Ph.D. dissertation, 144 p. + appendices. Cj Lake Dolomitic Breccia; breciated Setterholm, D.R., Runkel, A.C., Cleland, J.M., Tipping, R., Mossler, Willow Water-Supply Paper 2219, 56 p. D Contact marks a major erosional Os 36 31 1998 River Delta Environmental Consultants, Inc., 1992, Annual ground water J.M., Kanivetsky, R., Hobbs, H.C., 1991, Geologic factors affecting U K-bentonite bed (altered volcanic surface 92°45' Member Ops monitoring report to the Minnesota Pollution Control Agency for Ray's the sensitivity of the Prairie du Chien-Jordan aquifer: Minnesota R. 16 W. ash bed

North Star Truck Stop, Lakeland, Minnesota: Delta Report no. 11- Geological Survey Open-File Report 91-5,18 p. Os River 160-180 Sloan, R.E., 1964, The Cretaceous System in Minnesota: Minnesota ÐCj Island HYDROSTRATIGRAPHIC CHARACTER 92-002, sec. 3.1.3 on p. 3. Site report on file at the Minnesota 316 1 6 New T C R O P E X P O S D I N U

Geological Survey Report of Investigations 5, 64 p. 6 Formation Shakopee Richmond Pollution Control Agency. ÐCsf COMPONENTS Mixed carbonate and clastic Stone, D.J., 1980, The geology of the Upper Dunleith Formation (Prosser Opd Freeze, R.A., and Cherry, J.A., 1979, Groundwater: Englewood Cliffs, Goose R. 15 W. Fine clastic (very fine sand- rocks N.J., Prentice Hall, 604 p. Member, Galena Formation) of Middle Ordovician age in southeastern Lake Hagar stone, siltstone, or shale) Frey, M.G., 1937, Geology of the Red Wing District: Minneapolis, Minnesota: Duluth, University of Minnesota, M.S. thesis, 84 p. 18 ÐCj Fracture or solution feature City Visocky, A.P., Sherrill, M.G., and Cartwright, K., 1985, Geology, Member University of Minnesota, Minneapolis, M.S. thesis, 36 p. WELCH ÐCig PIERCE CO Shale

61 Prairie du Chien Group Kanivetsky, R., 1988, Bedrock hydrogeology, pl. 5 in Balaban, N.H., hydrology, and water quality of the Cambrian and Ordovician Systems RELATIVE PERMEABILITY Opd LOWER ORDOVICIAN LOWER ed., Geologic atlas of Olmsted County, Minnesota: Minnesota in northern Illinois: Illinois State Geological Survey and Illinois Coarse clastic (quartzose 105-200 ÐCe sandstone) High (aquifer) Coon Geological Survey County Atlas Series C-3, scale 1:100,000. State Water Survey Cooperative Groundwater Report 10, 136 p. Ops Oneota Dolomite Valley Wall, D.B., and Regan, C.P., 1994, Water quality and sensitivity of the Os Ops Kanivetsky, R., and Walton, M., 1979, Discussion accompanying Carbonate rock Member Prairie du Chien–Jordan aquifer in western Winona County, Minnesota: Os Opd Low (likely confining unit) Kanivetsky, R., Hydrogeologic map of Minnesota, bedrock T. 113 N. T. 113 N. Cj 30- hydrogeology: Minnesota Geological Survey State Map Series S-2, St. Paul, Minnesota Pollution Control Agency, Water Quality Division, Jordan Sandstone 100 11-page insert. 65 p. + appendices. ÐCe St. Lawrence 40- Wenck and Associates, Inc., 1997, Phase II detailed site investigation ÐCmt Libra, R.D., and Hallberg, G.R., 1985, Hydrogeologic observations from ÐCig Ð Formation 50 Ð Cig report and phase III work plan for the hydrogeologic investigation of Opd Ce River multiple core holes and piezometers in the Devonian-Carbonate aquifers D ° G the proposed Red Wing ash disposal facility expansion: Prepared for ÐCig U D 92 30' Ð in Floyd and Mitchell Counties, Iowa: Iowa Geological Survey Open ÐCmt Cig Northern States Power Company: p. 1–36. Site report on file at the Os Welch ÐCsf U G File Report 85-2, p 1-20. Reno ÐCj R. 14 W. Member Csf Miller, R.T., 1984, Anisotropy in the Ironton and Galesville Sandstones Minnesota Pollution Control Agency. D WISCONSIN R. 13 W. G Cannon Opd ÐCj U near a thermal-energy storage well, St. Paul, Minnesota: Ground Wacouta MINNESOTA B' G Bay ÐCmt Ð Water, v. 22, p. 532–537. Ce 165-175 ÐCsf ÐCj ÐCe ÐCsf ÐCsf Tomah Mbr ÐCsf Red Wing 31 Opd Ops 36 Lake Pepin Birkmose

36 ÐCig 31 Formation Franconia 36 G 31 Ops 31 Wacouta Wacouta Beach Member Creek Opd WACOUTA Ironton and Gales- 50- DAKOTA CO R. 17 W. Spring Cr D Cig U ville Sandstones 65 Os ÐCj Brook ÐCj 20 Ops Opd G Cr Pine Cr CANNON FALLS 1 Ð 1 6 PEPIN CO 1 6 6 1 6 Cig

Os Creek G 6 ÐCj ÐCe ÐCj Ops Eau Claire Ops VASA FEATHER STONE Bullard ÐCsf ÐCmt Ce Os Formation Od River ÐCj Os Old 120-140

58 61 Frontenac Opd ÐCe 93°00' Belle 1 Ð UPPER CAMBRIAN Cannon 63 Cig Trout Hay D T. 112 N. R. 18 W. Opd Frontenac ÐCsf Lake ÐCig U

Byllesby Opd Os 19 FLORENCE Ops Os Ð ÐCe Csf 5 2 Ogw Opd Ð Ð Vasa Ops Cj Csf 56 Os Opd 44°30' Mt. Simon Cannon Falls Cmt ° ÐCigCr Sandstone 44 30' Os HAY CREEK Wells Opl Os Ð ÐCig Ogw Csf ÐCsf Ops Creek Opl as 250 As much 19 ÐCsf Hay Creek Ops 8 Od

D

Opd Ops T I O NS W N A S U B C R O P M D E S H O DAKOTA CO DAKOTA ÐCj U Od Proterozoic rocks T. 112 N. Os Opd ÐCj Ops Creek STANTON Os Stanton Prairie Ops Sugarloaf Central Ogs Os Creek Point Os Os Ogw Creek Ogp ÐCsf ÐCmt Os 25 Opl 31 36 U Opd ÐCe 31 31 31 31 36 D Ð ÐCig Ogw 36 31 1 36 36 Ce 52 36 Ops Ops DESCRIPTION OF MAP UNITS RICE CO RICE Opl 3 Wells Ops Ogp White Os R. 13 W. 92°15' Prosser Limestone—Very fine grained, thin- and crinkly bedded limestone; dolomitic Ogw WABASHA CO Ops Rock Ð near top. Fossils form thin coquina layers. Distinguished from Cummingsville For- Butler Creek Ogc Hay Csf Clear Os 1 6 1 6 1 6 1 6 1 6 Ops mation below by near-absence of shale interbeds. As much as 70 feet thick. Ogp Ogc Od Ops Cummingsville Formation—Interbedded limestone and shale. Shale is green-gray, cal-

careous, thick bedded in lower part. Limestone is fine grained, fossiliferous, thin and Creek Od River Ogc crinkly bedded. Unit presents a sawtooth profile in exposure owing to the inter- Ogp GOODHUE Opd Creek bedding of weathered, soft, recessive shale and hard limestone. Unit thickness, 70–75 Os Ogc Ops Os ÐCj Ogw Od BELLE CREEK feet. Opl Opl Ogw Table 1. Hydrostratigraphic components of Paleozoic strata in Goodhue County. Od Decorah Shale—Green-gray shale with thin interbeds of fossiliferous limestone. Fer- 6 Ops ruginous oolites at top. Unit thickness, 60–65 feet. 14 COMPONENT DESCRIPTION CEMENTATION PERMEABILITY Belle ÐCj T. 111 N. Os Opl Platteville Formation—Fine-grained, fossiliferous, thin- to medium-bedded limestone; Od Ogc Fine clastic Very fine grained sandstone, Strong to moderate Low to very low LEON Os T. 111 N. siltstone, and shale sandy at base. Thin shale beds are most common in upper part. Contacts with units Opl above and below are gradational. Unit forms prominent ledge where it caps small 1 Coarse clastic Fine- to coarse-grained sandstone Mostly uncemented High to very high Ogw Os 9 9 WARSAW Sogn D (quartzose) (98% quartz) plateaus. Unit thickness, 10–15 feet. Od Ogw Ogp U Carbonate Limestone or dolostone; minor shale Strong Moderate to high where fractures Glenwood Formation—Sandy, green-gray shale containing phosphatic grains as much as Dennison 9 BELVIDERE and sandstone and solution features are present one centimeter in diameter. Thin, quartzose, fine- to coarse-grained sandstone inter- U Mixed carbonate Interbedded siltstone, very fine to Friable to strongly High to low, depending on dominant beds are common. Unit thickness, 5–15 feet. Ogc D Os Goodhue Opd and clastic very coarse grained sandstone cemented rock type Od 2 Os St. Peter Sandstone—Mostly very fine grained to medium-grained, poorly cemented Ogc Ops sandstone. Lacks structure or, less commonly, shows subtle cross-stratification, Ogc Ogc Opl Ops Cannon especially in uppermost part. Some intensely burrowed, pale-green shaly intervals. U Grain size becomes progressively finer upward in lower half, coarser upward in upper Od D half. A shale bed as thick as one foot in lower three feet of formation extends 31 31 36 36 31 36 31 36 36 31 Os D laterally at least across the northern part of county. Possible unconformity along basal Ogp U U Ops Os 16 D Bellechester Opd 16 contact. Commonly exposed along steep hill slopes that are held in place by caps of Platteville Formation. Unit thickness, 100–115 feet. Od Hader B 92°30' R. 14 W. Os 58 Ops Shakopee Formation—160–180 feet thick. 6 6 1 6 Little 1 Ogp 6 1 Willow River Member—Thin- to medium-bedded dolostone, sandstone, sandy dolostone, 1 INTRODUCTION The coarse clastic (quartzose) component is a mostly uncemented, moderately sorted Ogp Ops and minor amount of shale. As much as 150 feet thick. The map on this plate shows bedrock that is exposed at the land surface or lies to well-sorted, fine- to coarse-grained sandstone composed of about 98 percent quartz. Plug-sample tests indicate it has high to very high permeability and porosity due to its New Richmond Member—Quartzose sandstone as much as eight feet thick overlying 56 directly beneath unconsolidated deposits of Cretaceous and Quaternary age. The bedrock Opl Ogw intraclastic, oolitic dolostone and sandy dolostone. Basal contact is a disconformity. geologic cross sections show the bedrock formations from a third dimension, as they would relatively large, well-connected, intergranular pore spaces. Wells drawing water mostly from this component typically pump about 2–20 feet per day, indicating a moderate to high As much as 50 feet thick. 52 Os appear along the side of a trench cut 1200 feet below the land surface. The geologic WANAMINGO Od conductivity (Miller, 1984; Setterholm and others, 1991; Miller and Delin, 1993; Runkel, Opd Oneota Dolomite—105–200 feet thick. Od formations are very thin relative to their areal extent and would be only one-tenth as thick 1996a). Hager City Member—Dolostone and silty dolostone as much as 115 feet thick in as shown on the sections if no vertical exaggeration were used. The map and cross sections The carbonate rock component consists of limestone or dolostone with minor amounts medium to thick, irregular, tabular beds. Most beds are internally structureless or T. 110 N. are based on field mapping of outcrops, water-well records, engineering borings, drill faintly laminated, and have relatively minor vuggy porosity. Some beds have algal T. 110 N. Ogc of shale and sandstone. Fractures and solution features formed through karst processes are Aspelund cuttings, and geophysical logs (see Plate 1, Data Base); geologic studies by Frey (1937), lamination and are stromatolitic and vuggy, with secondary porosity and calcite Crain (1957), Sloan (1964), Stone (1980), and Sansome (1986) were also consulted. Where the principal influence on porosity and permeability, because porosity of the rock matrix is ZUMBROTA negligible. Permeability, therefore, varies substantially from place to place, depending on mineralization. Os Opd bedrock is buried by more than 100 feet of unconsolidated deposits (see Plate 5 for depth to Coon Valley Member—Interbedded sandstone, sandy dolostone, and minor amount of 246 the size, extent, degree, and interconnections of fractures and solution features, and on the bedrock), the geology is necessarily generalized because data on bedrock type and depth shale; member thickness, 20–85 feet. Lower contact is an unconformity, which is Od Ogc scale of the method used to determine it (Libra and Hallberg, 1985; Visocky and others, D are sparse. U 1985). In most places where such features are well developed, the component has moderate directly overlain by a poorly sorted sandstone bed containing pebbles of Precambrian River Os Bedrock is the consolidated sandstone, limestone, and shale that are exposed on the rocks that are as much as two centimeters in diameter. Od to highly conductivity, 1–40 feet per day (Delin and Woodward, 1985). However, in places Wanamingo MINNEOLA 10 steep bluffs along the Mississippi River and its tributaries, in rock quarries, and along Cj Jordan Sandstone—Sandstone consisting of a coarsening-upward sequence of two HOLDEN North Fork where fractures and solution features are few, such as where carbonate rock is deeply North Od roadcuts in Goodhue County. The rocks form distinguishable layers that are given formal distinct facies: (1) quartzose facies of mostly friable, yellow to white sandstone, and Opl Fork buried by younger bedrock, the component can have very low conductivity, even at a large Opl Os names like Jordan Sandstone, Decorah Shale, and St. Lawrence Formation (Mossler, 1987). (2) feldspathic facies of very fine grained sandstone, siltstone, and shale. About 30– Zumbro Forest scale (Libra and Hallberg, 1985; Visocky and others, 1985). Ogw Mills Zumbro The characteristics of each formation in Goodhue County are given in the Stratigraphic 100 feet thick. Od 60 The mixed carbonate and clastic component is composed of interbedded siltstone, Column and Description of Map Units. Csf St. Lawrence Formation and Franconia Formation. 31 31 36 31 Ogw 31 very fine to very coarse grained sandstone, sandy dolostone, and shale (Setterholm and Od 36 Creek 36 36 The bedrock layers were deposited as sediments in a shallow sea that covered southeastern Creek Opd others, 1991; Runkel, 1996b). The degree of cementation varies; beds of medium- to St. Lawrence Formation—Tan to gray, well-cemented, thin- to medium-bedded silty Zumbrota River Minnesota and the surrounding region 520–350 million years ago. Some unconsolidated dolostone and siltstone; thin shale beds. Dolostone contains variable amounts of clay, clay and sand of Cretaceous age (about 100 million years old) have been described in coarse-grained sandstone are typically friable, but very fine to fine-grained sandstone and Os 57 Cr siltstone commonly are strongly cemented. This component of mixed rock types varies silt, sand, and glauconite. Thin to medium beds of very fine grained sandstone are Kenyon Ogp 1 Goodhue County (Sloan, 1964), but mappable units of such sediments were not found in common, particularly in upper 20 feet. Unit thickness, 40–50 feet. 6 1 6 Ogc 1 6 Bitter markedly in permeability from bed to bed. Weakly cemented, coarse-clastic sandstone 1 6 the course of this study. Very small, isolated pockets of Cretaceous sediments (derived 60 Ops beds are likely to be highly permeable. The more strongly cemented, finer grained, clastic Franconia Formation—Mostly glauconitic, feldspathic, very fine to fine-grained Spring Shingle 60 from weathered Paleozoic bedrock) may be present in depressions like sinkholes. Such sandstone; green and gray shale and pink or tan, sandy, glauconitic dolostone. Intra- Pearl beds have low permeability (Setterholm and others, 1991). These finer grained clastic beds pockets were once mined for pottery clay, and their likely locations are shown on Plate 6, clasts and burrow mottling are common. Generally coarser grained and more poorly Ogp form the bulk of the component, and meager pumping data indicate a lateral conductivity Ogw Opl Geologic Resources. about one-fifth that of the coarse clastic (quartzose) facies (Runkel, 1996a). cemented than St. Lawrence. About 160–175 feet thick. Od Opl Os Reno Member (upper 90–100 feet)—Very fine grained to fine-grained glauconitic Creek Ogp Ogc The density and connection of fractures vary laterally and vertically and can markedly Ogw 11 USES OF THE MAP affect the hydrologic behavior of each of the components. Fractures and the connections sandstone interbedded with siltstone and shale. ° The bedrock geologic map provides some of the basic information needed for oversight 10 44 15' Tomah Member (medial 40 feet)—Interbedded, very fine grained sandstone, siltstone, 44°15' 1 of natural resources like ground water and minerals in Goodhue County. Information on among them are most abundant where bedrock is at or within 100 feet of the surface. 52 and shale; minor amount of glauconite. This member is finer grained and has more Ogp Opl PINE ISLAND bedrock is also used to prepare related geologic maps, such as Thickness of Quaternary Clastic components like heterolithic, very fine grained sandstone, siltstone, and shale have 56 shale than adjacent members 12 CHERRY GROVE Sediments (Plate 3), Bedrock Topography (Plate 5), and Geologic Resources (Plate 6). The low to very low intergranular permeability. Where near the surface, they may be orders of Birkmose Member (basal 30 feet)—Very fine grained to fine-grained sandstone; abun- water within the bedrock formations is perhaps the most important resource of all, and magnitude higher in conductivity, because a substantial component of flow is along fractures. Od Dry Run Conversely, some carbonate units may have a relatively low conductivity and act as confining dant glauconite. Dolomite cement and sandy dolostone beds are common. T. 109 N. understanding how the various bedrock types convey or impede the flow of ground water is Ogc ROSCOE Cig Ironton Sandstone and Galesville Sandstone—Fine-grained to very coarse grained T. 109 N. imperative. Water-bearing attributes of the rocks are used with other information on ground units where they are covered by younger bedrock and have little secondary porosity (Libra KENYON Opl Creek quartzose sandstone. Total unit thickness, 50–65 feet. 11 Roscoe Opl water to define the aquifers and confining units depicted in the hydrogeology plates of Part and Hallberg, 1985; Visocky and others, 1985). Additionally, flow along fractures may Ironton Sandstone—Ironton is more poorly sorted than Galesville and has coarser sand- B of the atlas. The likelihood of sinkhole formation and the sensitivity of ground water to dominate, even in the coarse clastic (quartzose) component, which has high intergranular Ogc Ogw Ogw stone beds. Substantial shale and siltstone form thin interbeds or a matrix in poorly Od contamination are also determined in part by the bedrock geology. permeability where it lies near the surface. 13 Os sorted sandstone. White, brown, or black shell fragments are locally common in Devlin Ops Delineation of Aquifers and Confining Units Zumbro Ops HYDROSTRATIGRAPHY upper 10–15 feet. Subtle disconformity in middle of Ironton is capped by pebbly, Os Fork River The coarse clastic (quartzose) and karstic carbonate rock components likely contribute coarse to very coarse sandstone bed. Above this bed, grain size of Ironton becomes Skyberg Hydrostratigraphic components are distinguished and characterized by their porosity Middle Pine most of the yield to water wells developed in Paleozoic strata. The fine clastic component finer upward and passes transitionally into the Franconia Formation; below this bed, Creek No.Opl Br. and permeability, which are the fundamental controls on ground-water movement. Porosity can potentially yield moderate quantities of water, particularly where it is fractured near the 31 36 31 36 Island 36 grain size becomes finer downward. 36 31 is simply the open spaces in a rock, such as cracks, voids, and tiny pore spaces. Permeability surface. More importantly, it acts as a confining unit that separates coarse clastic and Ogc Opd Ogp 31 Galesville Sandstone—Fine to coarse grained, well to moderately sorted; minor amounts RICE CO Opl Od WABASHA CO pertains to the relative ease with which a rock can transmit a liquid through these open Os Os karstic carbonate aquifers (Wenck and Associates, Inc., 1997). The mixed carbonate and of shale, siltstone, and very fine grained sandstone beds. Lower one-third locally A R. 17 W. spaces. The conductivity of a rock, also discussed below, is the rate at which water can DODGE CO 93°00' R. 18 W. 92°45' R. 16 W. DODGE CO OLMSTED CO R. 15 W. OLMSTED CO clastic component contains individual beds that can yield moderate quantities of water, but intertongues with feldspathic, very fine grained sandstone of underlying Eau Claire SCALE 1:100 000 move through it. Digital base modified from 1990 Census TIGER/Line Files GIS compilation and cartography by where greater than 10 feet thick, it apparently also acts as a confining unit (Setterholm and Formation. of U.S. Bureau of the Census (source scale 1:100,000); 1 0 12345 MILES Joyce Meints and Philip Heywood Hydrostratigraphic Components others, 1991). Unfractured carbonate rock can also serve as a confining unit (Visocky and Ce Eau Claire Formation—Commonly interbedded sandstone, siltstone, shale; thin to county border files modified from Minnesota Department of others, 1985; Alexander and others, 1991; Barr Engineering, 1996). Transportation files; digital base annotation by Minnesota 1 0 12345 6 7 8 KILOMETERS The Paleozoic bedrock in Goodhue County consists of four distinct hydrostratigraphic medium-thick beds. The sandstone is very fine grained to fine grained, tan, variably Geological Survey components, which have been defined and characterized in studies elsewhere in southeastern Two of the most widely used aquifers in Goodhue County, the Franconia-Ironton- glauconitic, laterally stratified, hummocky stratified or bioturbated. Siltstone is tan to Universal Transverse Mercator Projection, grid zone 15 Minnesota (Setterholm and others, 1991; Miller and Delin, 1993; Runkel, 1996b). The Galesville and the Prairie du Chien–Jordan and are not single, hydraulically connected gray, laterally stratified or bioturbated. Shale is gray to greenish-gray. Gray to black 1927 North American Datum components are (1) fine clastic, (2) coarse clastic or quartzose, (3) mixed carbonate and aquifer systems as previously believed (Kanivetsky and Walton, 1979). Pumping tests shell fragments are common. Unit coarsens upward, with shale and siltstone replaced clastic, and (4) carbonate. A clastic rock is a sedimentary rock composed principally of (Miller, 1984; Delta Environmental Consultants, Inc., 1992; Miller and Delin, 1993) and in abundance upsection by sandstone. Uppermost 10–20 feet is mostly very fine broken fragments derived from pre-existing rocks. The stratigraphic position of these carefully collected measurements of local static-water levels (Delta Environmental Consultants, grained sandstone and siltstone. About 120–140 feet thick. components relative to the formally defined groups, formations, and members of the Paleozoic Inc., 1992; Wenck and Associates, Inc., 1997) clearly indicate that water in the upper part Cmt Mt. Simon Sandstone—Mostly white to yellow, fine- to coarse-grained, friable, B Bellechester Quaternary B' Ops of the Franconia is hydraulically separated from water in the lowermost Franconia, Ironton, 1200 Ops deposits 1200 rocks is shown in the Stratigraphic Column. Porosity and permeability were determined quartzose sandstone. Scant subsurface data indicate that the Mt. Simon is as much as Opd Ops through laboratory tests of plug samples and hydraulic testing of water wells in southeastern and Galesville formations. Some fractured, carbonate-cemented rock in the lower part of 250 feet thick. The top of the Mt. Simon is marked locally by a thin "rusty" Ops Ð 1000 Cj Wells 1000 the Franconia where it is at or near the surface is a source of many springs in the county Opd Opd Minnesota, including Goodhue County. sandstone that contains iron-coated, fine to coarse sand grains and abundant black Opd Creek Miss. River ÐCj ÐCj and is perhaps the only highly permeable conduit for ground water within the Franconia. 800 ÐCsf 800 The fine clastic component consists of very fine grained sandstone, siltstone, and shell fragments. Beds of variegated shale, siltstone, and feldspathic, very fine grained ÐCsf ÐCj (Lake Pepin) ÐCsf shale in thin to medium-thick beds that are strongly to moderately cemented. The component The Prairie du Chien–Jordan aquifer is also two distinct aquifers, an upper carbonate sandstone are common, particularly in the upper two-thirds of the formation. Pebble ÐCig Ð 600 ÐCe Ð Csf ÐCig Quaternary 600 Cig deposits has low to very low relative permeability, several orders of magnitude less than that of the aquifer and a lower, quartzose aquifer, which are separated by an intervening confining ÐCe conglomerate or pebbly sandstone is common in the lowermost 100 feet of the ÐCe unit composed of the mixed clastic and carbonate component. Hydraulic separation of the 400 ÐCmt ÐCe ÐCmt 400 coarser grained sandstone of the coarse clastic (quartzose) component. Vertical conductivity formation. Elevation in feet Elevation in feet is low to very low in the fine clastic component, commonly 0.001–0.00001 (10-3–10-5) feet carbonate and quartzose aquifers is indicated by several lines of hydrologic evidence gathered Proterozoic rocks, undifferentiated—Samples from a few deep water wells that 200 200 per day for interbedded, very fine sandstone and shale (Miller and Delin, 1993), and as low in Goodhue and adjacent counties, including potentiometric data (Kanivetsky, 1988; Alexander penetrated the entire Mt. Simon beneath the city of Red Wing indicate that the rocks SEA SEA as 0.0000001 (10-7) feet per day for units composed almost entirely of shale (Freeze and and others, 1991), pumping tests (Barr Engineering, 1996), and ground-water chemistry beneath the Mt. Simon include buff to tan quartz arenite of the Hinckley Sandstone LEVEL Vertical exaggeration x 10 LEVEL Cherry, 1979). Horizontal conductivity in interbedded sandstone and shale is typically (Alexander, 1990; Setterholm and others, 1991; Wall and Regan, 1994). and arkosic red sandstone, shale, and siltstone of the Fond du Lac Formation. more than 100 times greater than vertical permeability (Miller, 1984; Setterholm and others, A 1991; Miller and Delin, 1993). A' DESCRIPTION OF MAP SYMBOLS 1400 North Fork 1400 US 52 Geologic contact—Approximately located; generally concealed. Quaternary deposits Zumbro River Quaternary Belle Ogp Ogp Ogp Ogc Creek Ogp deposits Ogc 1200 Opl Od Ogw Opl 1200 Ogc Ogc Od Ogc Minn. 19 Os Opl Opl Os Os Quaternary Ops Ops U Fault—Approximately located; generally concealed. U, upthrown side; D, down- Od deposits US 61 1000 Od Cannon 1000 Ops River Miss. D thrown side. GOODHUE COUNTY Os Os Os Ogw Ops Opd River 800 Ops Ogw Ops Opd 800 Ops Opl ÐCj Opd ÐCj AA'Line of section. Opd Quaternary 600 ÐCsf 600 ÐCsf deposits ÐCj ÐCj ÐCsf 400 ÐCig 400

Elevation in feet Elevation Ð Ð Csf Ð Csf Ð Every reasonable effort has been made to ensure the accuracy of the factual data on which this map interpretation is based; however, Csf Ð Ce in feet Elevation Cig Ð Cig the Minnesota Geological Survey does not warrant or guarantee that there are no errors. Users may wish to verify critical information; 200 ÐCig 200 ÐCmt sources include both the references listed here and information on file at the offices of the Minnesota Geological Survey in St. Paul. ÐCe ÐCe SEA ÐCmt SEA In addition, effort has been made to ensure that the interpretation conforms to sound geologic and cartographic principles. No claim LEVEL ÐCmt LEVEL is made that the interpretation shown is rigorously correct, however, and it should not be used to guide engineering-scale decisions 200 Vertical exaggeration x 10 200 without site-specific verification.

©1998 by the State of Minnesota, Department of Natural Resources, and the Regents of the University of Minnesota The University of Minnesota is an equal opportunity educator and employer GEOLOGIC ATLAS OF GOODHUE COUNTY, MINNESOTA