Prepared and Published with the Support of COUNTY ATLAS SERIES ATLAS C-11, PART A MINNESOTA GEOLOGICAL SURVEY THE MOWER COUNTY BOARD OF COMMISSIONERS AND THE MINNESOTA DEPARTMENT OF NATURAL RESOURCES, DIVISION OF WATERS Plate 6—Sand and Gravel Resources D.L. Southwick, Director and Bedrock Resources

R 18 W 93°00' R 17 W R 16 W 92°45'

56 1 6 6 1 6 1 R 15 W R 14 W 92°30'

er 16 iv R ek UDOLPHO Cre 7 oot k R ree 8 1 PLEASANT C y Waltham re VALLEY a C Sargeant 1 63 INTRODUCTION TO PLATE T 104 N The maps on this plate reflect only geologic criteria. Urban de- son 90 in ch b velopment and zoning laws obviously have a major impact on the n o a R Br availability of resources for mining. However, a map that attempted to SARGEANT T 104 N take these factors into account would soon be outdated. That kind of

C rapidly changing demographic information is best portrayed and man- e

d a WALTHAM aged with a computerized Geographic Information System (GIS). 218 r 20 RACINE For additional information on the geologic resources of Mower 1 County, see Mossler (1998). North 31 R 36 31 31 EXPLANATION TO THE iv 56 36 31 36 31 36 36 e Racine r SAND AND GRAVEL RESOURCES MAP

No r INTRODUCTION th R o b 6 6 Sand and gravel are mostly used for road construction, as in road base, 6 LANSING e 1 1 6 1 Lansing 1 rts Creek 6 1 43°45' 7 Bear 43°45' in mix for concrete and bituminous pavements, and on unpaved roads. It also 2 Fork is used in general construction. The potential sand and gravel resources shown DEXTER Creek on the map are secondary resources, chiefly because they contain less than 35 Brownsdale 2 percent gravel-size material. In addition to sufficient thickness and gravel content, and minimum of cover, a relatively wide range in size from sand to k ee gravel is desirable in a deposit, because different size mixtures are required for Cr k ar different uses. Sandy recent alluvium (map unit Qas on Plate 3) is not shown l Cree GRAND e Wo f MEADOW B as a potential resource on this map because it is generally gravel poor, and its position along rivers where the water table is close to the land surface makes Ramsey South Fork Mill Pond Creek T 103 N extraction impossible without pumping, dredging, or use of a dragline. Eolian T 103 N Deer RED ROCK Dexter Grand sand (map unit Qe on Plate 3) is not shown because it lacks gravel. Two 16 Meadow 16 physical properties also provide information on the suitability of sand and k 16 e 20 e gravel deposits as resources. They are (1) the content of spall materials, which Mur r phy C C are rock particles that will cause a pop-out in hardened concrete or bituminous re e k pavement, and (2) the resistance of aggregate to abrasion, which is determined

ins FRANKFORD by the Los Angeles Rattler (LAR) method. Data used in compiling this map b b D o were obtained from Minnesota Department of Transportation gravel-pit Maple View sheets. 8 36 DESCRIPTION OF MAP UNITS AND SYMBOLS 31 31 31 14 36 31 36 31 36 Areas shown in color are considered to have potential for aggregate resources, but reliable subsurface information is very limited beyond the confines of 16 90 Elkton existing pits. 1 6 6 1 6 1 6 1 6 1 Outwash of the New Ulm Formation—Dominantly gravelly sand 90 ek and sand, with generally only thin and scattered beds of gravel re r C (map unit Qno on Plate 3). Shale grains are present and may ee ver 3 D Ri limit the use of some deposits for concrete. However, total spall content is likely less than most other deposits in Mower County 3 Root due to a lower iron-oxide content. LAR values may also be Austin 56 somewhat better in New Ulm outwash, despite the shale con- Branch tent, because the outwash has fewer weathered-rock clasts than O 7 r c other deposits in the county. In general, shale content decreases h 105 South a 3 r T 102 N d CLAYTON T 102 N and locally derived weathered-rock clasts increase from west

C AUSTIN

r and north to south down the Cedar River. e

e MARSHALL k BENNINGTON Wisconsinan alluvium—Dominantly gravelly sand and sand; generally coarsens upwards; gravel beds in most deposits are in 3 the upper 10 feet (map unit Qs on Plate 3). Intervals containing more than 35 percent gravel compose on average less than 10 4 percent of a typical deposit, and they are absent in many.

Varco er Deposits having more-than-average gravel content are present Rose v er WINDOM i er iv Creek 4 4 R iv along a tributary of the Little Cedar River east and northeast of R R a R o w s Creek o a Adams, and along the Upper Iowa River in the vicinity of Le e I w r Io e Roy, where sand and gravel fills a narrow valley cut into the 218 p 31 ar 36 d 36 31 36 31 36 31 p 36 31 e U bedrock. A high water table limits the depth to which many C deposits can be conventionally mined. Upland sand and gravel—Dominantly gravelly sand and sand, 56 7 Qbs Qes

6 1 6 1 6 nch with interbeds of gravel, silt, and till (map units , , and 1 a 6 1

6 r 1 e tl Qrs on Plate 3). Although significant percentages of gravel are B it L h Adams t present in some deposits, iron-oxide cement and clay-coated r

o

N grains, in addition to fine-grained sediment interbeds, can 5 reduce the value of the deposit. Many of the smaller deposits are Taopi less than 20 feet thick. This unit includes small deposits of the 5 LE ROY 11 Ostrander Member of the (Plate 2) in 7 eastern Mower County. The Ostrander gravels generally have U p p a substantial component of iron oxide, clay, and chert pebbles. er Little LYLE 5 5 T 101 N NEVADA T 101 N Gravel pit—Active and intermittently active; inactive.

LODI Cedar Esker—Sinuous ridge of sand and gravel along Murphy 56 105 Creek, northwest of Maple View (sec. 20, T. 103 N., Iowa 14 R. 18 W.). The esker was deposited under glacial ice W R by meltwater of the Des Moines lobe. Borings made o iver o d b by the Minnesota Department of Transportation indicate ur y C R O i reek v that this deposit is better than most in the county because t er ter 6 Creek 6 6 parts of it contain beds greater than 20 feet thick that have greater than 35 percent gravel. Other similar Lyle Le Roy narrow deposits may exist in the vicinity of Murphy 31 31 36 7 36 31 Creek, but these may be covered by 10 feet or more of 31 36 31 36 36 till; also, they likely have a high-water table. 43°30' 43°30' 93°00' R 18 W R 17 W R 16 W 92°45' R 15 W R 14 W 92°30' Compiled 1997 Digital base modified from 1990 Census TIGER/Line Files SCALE 1:100 000 Cartography by Joyce Meints and Philip Heywood of U.S. Bureau of the Census (source scale 1:100,000); 1 0 12345 MILES Graphic design by Philip Heywood county border files modified from Minnesota Department of Transportation files; digital base annotation by Minnesota 1 0 12345 6 7 8 KILOMETERS Geological Survey Universal Transverse Mercator Projection, grid zone 15 1927 North American Datum SAND AND GRAVEL RESOURCES

By Gary N. Meyer

1998 MOWER COUNTY

° R 18 W 93 00' R 17 W R 16 W 92°45'

EXPLANATION TO THE BEDROCK RESOURCES MAP 56 1 6 6 1 6 1 ° R 15 W R 14 W 92 30' CARBONATE-ROCK RESOURCES er Carbonate-rock quarries—Active; inactive. The locations 16 iv R ek UDOLPHO Cre of some quarries mentioned in older reports could 7 oot k not be identified. R ree 8 1 PLEASANT C y NC Quarry that formerly produced natural cement used in Waltham re VALLEY a mortar. C L Quarry that formerly produced rock burned for lime. 1 Sargeant 63 T 104 N S Quarry that formerly produced speciality products, e.g., flux, mineral food, and poultry grit. son 90 in ch b n o DH M-4 Location of drillholes sampled for chemical composition a R Br B of carbonate rock—Approximately located. SARGEANT T 104 N

C CH-M-5 Location of section of exposed quarry wall sampled for e

d

a WALTHAM chemical composition of carbonate rock. 218 r 20 RACINE Fe 1 Primary Carbonate-Rock Resource—A primary resource meets the following criteria: North 1. Bedrock is generally less than 10 feet below land surface. The 31 R 36 31 31 iv 56 36 31 36 31 36 36 e Racine areas were compiled from Minnesota Geological Survey data on r bedrock outcrops, water-well and soil-borings data, soil maps of

No r the U.S. Soil Conservation Service, and estimation of the areal th R o 6 extent of shallow subcrop as inferred from topographic maps. 6 b 1 6 1 LANSING 1 erts 1 6 Lansing Creek 6 1 2. Laboratory tests indicate that the resource has acceptable physical 43°45' 7 Bear 43°45' 2 Fork and chemical properties for aggregate. Creek 3. Resource is inferred to have sufficient thickness (25 feet of more) Brownsdale 2 DEXTER for economic development. Many areas mapped as shallow bedrock are likely to have high water tables, making them less economically k viable. ee DH M-4 Cr eek ear Wolf Cr GRAND B Lithograph City Formation—Area underlain by as much as MEADOW 50 feet of lithographic limestone and dense dolostone having Ramsey South Fork minor thin shale partings. Unit becomes progressively Mill Pond reek T 103 N eer C T 103 N RED ROCK Dexter Grand D thinner toward northern margin of mapped area. 16 Meadow 16 Spillville Formation—Area underlain by as much as 75 feet

k of dolostone and calcareous dolostone. The unit is thinnest 16 e 20 e Mur r near the northern and western margins of where the Spillville phy C C re is mapped as a primary resource. e k

ins FRANKFORD b Secondary Carbonate-Rock Resource—Bedrock is inferred to be 10– b Maple View D o 25 feet below land surface but may be shallower in some areas.

8 Lithograph City Formation—The formation is about 20 to 36 25 feet thick in areas mapped. The upper lithographic 31 K 31 14 36 31 36 31 36 31 limestone member is absent due to erosion; therefore, the formation in these areas is less desirable as an aggregate 16 90 Elkton resource. Spillville Formation—In southerly parts of where the Spillville 6 1 6 1 6 1 6 1 6 1 90 is mapped as a secondary resource, where the formation ek re is adjacent to the overlying Pinicon Ridge Formation, nearly r C ee er the full thickness of the Spillville may be available for D Riv 3 development. Along its northern margins, and along Bear

Root Creek, where the Spillville is in proximity to the underlying 3 , the Spillville is very thin and may Austin 56 Branch be absent. Stewartville Formation—The formation is inferred to lie at O 7 r c shallow depths (25 feet and less) at the mapped location; h South a 105 r MG-88-27 3 T 102 N d CLAYTON T 102 N however, it may be covered by a variable thickness of the

C AUSTIN r

e shaly , and the surficial water table

e MARSHALL k NC BENNINGTON may be high. Tests done in neighboring counties indicate that the formation should have acceptable physical properties 3 CH-M-2 for aggregate. 4 Other Carbonate-Rock Resources—Mapped only in areas where depth

Varco er to bedrock is estimated to be 10 feet or less. These resources Rose v er DH M-2-1 WINDOM i er iv Creek 4 4 R iv may not be suitable for most uses due to substandard physical R R a R o w s Creek o a properties. DH M-2-2 e I w r Io e 218 p 31 ar 36 Coralville Formation and upper part of the Little Cedar d 36 31 36 31 36 31 p 36 31 e U C Formation—The upper Coralville has numerous shale beds and partings; the basal 15–20 feet is principally dolostone, 56 7 but may be too thin to be economical and has marginal

6 1 6 1 6 nch 1 a 6 1

6 r 1 e test values. The uppermost Little Cedar also has shaly tl B it L beds and unsatisfactory physical properties. h Adams t r o Lower part of and Pinicon Ridge

N 5 Formation—These units abrade easily and have extremely Taopi high insoluble residue contents. 5 LE ROY 11 7 FILLMORE COUNTY IRON DISTRICT U p p er Fe Former open-pit iron mine. Little LYLE 5 5 Boundary of property leased by mining company where T 101 N NEVADA T 101 N LODI economic quantities of iron ore were extracted.

Cedar 56 105 CLAY RESOURCES Iowa 14 MG-8C-35 K Former open-pit mine in claystone. W R o iver o d b MG-8C-35 Samples from shallow auger holes—Samples provide ur S y C R O i reek v information on texture, clay mineralogy, rock type, t er ter 6 Creek 6 6 CH-M-5 B and color. Le Roy Area underlain by Cretaceous claystone and clayey Lyle siltstone at depths of less than 25 feet. 31 31 36 7 36 31 31 36 31 36 36 L 43°30' 43°30' ° R 18 W R 16 W ° R 15 W R 14 W ° REFERENCE CITED 93 00' R 17 W 92 45' 92 30' Compiled 1997 Digital base modified from 1990 Census TIGER/Line Files SCALE 1:100 000 Cartography by Joyce Meints and Philip Heywood Mossler, J.H., editor, 1998, Contributions to the geology of Mower of U.S. Bureau of the Census (source scale 1:100,000); 1 0 12345 MILES County, Minnesota: Minnesota Geological Survey Report of county border files modified from Minnesota Department of Graphic design by Philip Heywood Transportation files; digital base annotation by Minnesota Investigations 50. 1 0 12345 6 7 8 KILOMETERS Geological Survey Universal Transverse Mercator Projection, grid zone 15 Every reasonable effort has been made to ensure the accuracy of the factual data on which this 1927 North American Datum map interpretation is based; however, the Minnesota Geological Survey does not warrant or guarantee that there are no errors. Users may wish to verify critical information; sources include both the references listed here and information on file at the offices of the Minnesota Geological Survey in St. Paul. In addition, effort has been made to ensure that the interpretation conforms BEDROCK RESOURCES to sound geologic and cartographic principles. No claim is made that the interpretation shown is rigorously correct, however, and it should not be used to guide engineering-scale decisions without site-specific verification. By John H. Mossler

1998

©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 MOWER COUNTY, MINNESOTA