Journal of the Minnesota Academy of Science Journal of the Minnesota Academy of Science

Volume 49 Number 1 Article 3

1983

Identification and Characterization of Three Glacial Tills in Identification and Characterization of Three Glacial Tills in

Kandiyohi County, Minnesota Kandiyohi County, Minnesota

Allan G. Giencke United States Department of Agriculture

Richard O. Paulson United States Department of Agriculture

James R. Crum University of Minnesota, St. Paul

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Recommended Citation Recommended Citation Giencke, A. G., Paulson, R. O., & Crum, J. R. (1983). Identification and Characterization of Three Glacial Tills in Kandiyohi County, Minnesota. Journal of the Minnesota Academy of Science, Vol. 49 No.1, 7-9. Retrieved from https://digitalcommons.morris.umn.edu/jmas/vol49/iss1/3

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I dent if ication and Characterization of Three Glacial Tills in Kandiyohi County, Minnesota

A LLA G . GlE CKE,* RICHARD 0. PAULSO , ** AND JAMES R. CRUM ***

ABSTRACT - During the course of the Kandiyohi Co., Minnesota, soil survey, three dif­ferent glacial tills were recognized and separated from what was formerly thought to be one homogeneous glacial till. Tile first glacial till is from the Des Moines Lobe ice advance. It has a fine-loamy particle size, friable consistency, and appreciable amounts of Cretaceous shale fragments. The oven-dry bulk density ranges from 1.3 to 1.5 glee. The second glacial till is from the Wadena Lobe ice advance. It has a coarse-loamy particle size, friable consistency, oven-dry bulk density of 1.5 to 1.7 glee, and small amounts of Cretaceous shale fragments. The third glacial till is thought to be pre-Wisconsin. Evidence suggests th is till was buried and later thrust to the surface during the advance of the Wisconsin Age ice lobes. This "older" till, tentatively named " Kandiyohi ", has a fine particle size, firm or very firm consistency, and appreciable amounts of fine, rounded shale fragments. The oven-dry bulk density ranges from 1.7 to 2.0 glee. The inherent properties of the soils formed in each glacial till affect use and management. Therefore, a different catena of soils is mapped on each of the three glacial tills.

INTRODUCTION

During the first few years of a soil survey, the properties of many soils are described and measured on samples from the modal si tes co provide a basis for the mapping-un it kgend to be used in the survey area. In Kandiyohi county (Fig. 1), a deta iled study of the stratigraphy and range of characterist ics of glacial till was incorporated into chis investigative part of the survey co determine if major geomorphic areas consisted of one homogeneous glacial till, as existing literature suggested, or if there were contrasting tills within these geomorphic areas.

Figure 1. Location of Kandiyohi county within Minnesota

The lowest lying (elevation = 1100 feet) geomorphic area in this study was the Olivia till plain (Fig. 2) formed by the Des Moines Lobe advance during the Wisconsin Age (1). This till plain is nearly level co gently undulating; local relief is commonly 2 co 8 feet. The next higher ( = 1200 feet) geomorphic area in th is study was the Alexandria Moraine Complex (Fig. 2), formed by an advance of the Wadena Lobe during the Wisconsin Age (2,3,4). This terminal moraine is typically rolling to steep wi th a local relief of IO to 40 feet . The highest lying ( = 1250 feet) geomorphic area is a part of the Alexandria Moraine Complex D (Fig. 2). It is gently und•J lating to hi lly with local relief of 5 to 25 feet. Its mode of formation is not clearly understood. Evidence suggests this glacial rill is much older than the Wisconsin Age. Deep borings suggest this till was buried and lacer thrust to the surface by Wisconsin Age ice advance (5). This t ill is proposed as the "Kandiyohi" t il l.

METHODS AND MATERIALS

When characterizing soils, the most commonly-used measures are: a) Particle-size D istribution (6), b) Organic Carbon, c) pH (6), d) Calcium C arbonate Equivalent, e) Bulk Density (6), D Coarse-fragment Analysis, and g) Engineering Tests. (8).

Particle-size distribution, bulk density, course-fragment analysis, and engineering tests provided the best indication of differences between the glacial t ills in Kandiyohi county and are discussed in this paper.

• U.S. Dept. Agriculture, Soil Conservation Service, WIiimar, Minn. • • U.S. Dept. Agriculture, Soil Conservation Service, St. Peter, Minn. • • • Dept. of Soil Science, University of Minnesota, St. Paul, Minn. Journal of, V0lume Forty-nine, No. I , 1983/84

The engineering tests can be grouped into three general categories: (I) Consistency Tests and Indices (Liquid Limit and Plasticity Index), (2) Moisture-Density Tests (Maximum Density and Optimum Moisture Content), and (3) Engineering Classification (AASHT O Class, G roup Index, and Unified Class) (Table 1).

The consistency tests correlate co the particle-size distribution

7

. ,.._

"" "" '\. OUTWASH "" ~ ' .... Sunburg ' / - - /

- - ' .,,,,,.-11111 ~ ' /

I I I'\,

"l L, --....i .,._

' I"-. .....,

• Spicer

~, r111 ~-,-~

,._ .,._ .... . 1 , -f':'twa rer

Pennock I I 1.~ (..:... . I I I I e_

Willmar • tKandiyoh i I

~

' ,_

Lake Lillian •

24 miles -------~ £IIIJ7 OLIVIA TILL PLAIN (Des Moines Till) ~ ALEXANDRIA MORAINE COMPLEX (Wadena Till) ,ffl±V ALEXANDRIA MORAINE COMPLEX (Kandiyohi Till)

Figure 2. Major geomorphic areas and glacial till bodies under Investigation - Kandiyohi County

of a soil. Clayey materials generally have high liqu id limits and poor engineering properties. Sandy soils (low clay content) generally have low liquid limits and good engineering properties.

During road and other construction projects it is best for the soil materia l to be compacted to a maxi mum to develop the best engineering properties of the material. The optimum moisture content in Table I represents the proper moisture content at which the maximum density can be achieved with construction equipment.

The engineering community has developed classification systems for soil materia ls relati ve to their construction qua lity. The American Association of State Highway and Transpor­ta tion Officials (AASHTO) developed a system of soil classification based upon the observed field performance of soils under highway pavements. Under thi system, soils with imilar load-carrying capacities are grouped together, with the A-1 class rating best :ind A-7 the poorest.

The Group Index is a function of he liquid limit, the plasticity index, and the amou nt of material passing a number 200 sieve (8). A group index of zero indicates a good subgrade material and an index above 20 indicates a poor subgrade material.

The Unified Class ification i another system developed for soil materials. This system is based on plasticity - compre~ibi lity characteri~tics for those soils where ·ilts and clays affen the behavior (8).

B

The samples analyzed from the three glacial ti lls in Kandiyohi county were collected from sites widely distributed within each of the geomorphic areas (Fig. 2) to provide a range in charac­teristics. The characterization analyses were done by the Soil Survey Laboratory, Minnesota Agricultural Experiment Station, St. Paul, Minnesota. The engineering tests were performed by the Minnesota Department of Transportation, St. Paul, Min­nesota.

GEOGRAPHIC AREAS

Olivia Till Plain., The Des Moines Lobe till in this geomorphic area is characterized by a fine-loamy particle size (Fig. J), friable consistency, and appreciable amounts of platy Cretaceous shale fragments. An average of 10 till samples shows the texture to be loam with about 40 percent sand, 36 percent silt, and 24 percent clay (Fig. 3). The bulk density of oven-dry samples above a dep­th of 60 inches ranged from 1.3 to 1.5 glee. Engineering test results are summarized in Table I.

These data indicate an intermediate engineering quality com­pared to the Alexandria moraine till and the Kandiyohi till. The real value of these data , in rhi study, is in observing the separation of the three tills. Engineering properties, and therefore the interpreta tions applied to soils, arc in many cases used to define soil series. The soil developed on these glacial till behave differently and have the accompanying d ifferent inter­pretations for agricultural drainage, septic tank adsorption fields, crop suitability, build ing site development, and other com­ponents of Soil Survey Reports.

Alexandria Moraine Complex (Wadena Till) . The Wadena Lobe till in this geomorphic area has a coarse-loamy particle size (Fig. J). The till is friable to very friable and has very few (if any) fragments of C recaceuu · ~hale. A n analysis of IO till samples shows the texture to be fine sandy loam with about 59 percent and, 28 percent ilt, and 13 percent clay (Fig. 3). The oven-dry

bulk densi ties above a depth of 60 inches ranged from 1.5 to 1. 7 glee. Engineering test data indicate that these soils are rather well suited for use as construction material (Table !). One unusual feature of this till is that it has relict mottles in a random and unpredictable pattern that do not reflect a present-day moi ture regime.

Table 1. Engineering test data for samples taken from the type locat ion of each till. These analyses run by the Min­nesota Department of Transportat ion.

Alexandria Des Moines moraine lobe Kandiyohi

Analysis Till Till Till

Liquid Lim it 27 38 59

Plasticity Index 6 15 28

AASHTO Class A-4 A~ A-7

Group Index 0 7 28

Max. Density 120.4 109.5 95.1

Opt. Moisture 13.9 17.6 27.6

Unified Class SM -SC CL CH

11,c Minnc;;m a Accidemy ofScienc~

0\\ Clay

VERY FIN,_ CLAYEY

FINE­

CLA7~;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;.,__...,;;=;._._::.,__.,,;;,;;;;;,,:,._;;,:~-·

FINE- I LOAMY

\ ---- - ----"--------1. FINE­SI LTY 1· _________ .., ____ ..,.. ____ .. .._ ___ _ \ \

Loam .,,_ COARSE­~ SILTY

\ 100 percent sand 0

'---SANDY-----> '---- COARSE-LOAMY _ ____ __.

Figure 3. USDA Textural Triangle. Grain size distribution of Des Moines t ill ■ , Wadena ti ll • , and Kandiyohi till.A.. FINE-LOAMY, etc. is the family texture class as described in Soil Taxonomy. Samples were analyzed by the Minnesota Agricultural Experiment Station.

Alexandria Moraine Complex (Kandiyohi Till). The Kandiyohi till is characterized by a fine-clayey particle size (Fig. 3). The con­sistency is firm to very firm, and there are appreciable amounts of fine rounded Cretaceous hale fragments. An analysis of IO till samples shows the average texture to be clay loam with about 24 percent sand, 39 percent silt, and 37 percent clay (Fig. 3). Oven·dry bulk densities from samples above 60 inches ranged from 1.7 to 2.0 glee. Engineering test data indicate that this material is very poor for use as a construction material (Table 1). 17-,e high clay content and high bulk densities make this a very difficult material to work with.

DISCUSSION · Tills and Kindred Soils. In a soil survey report, individual

soils are separated by mapping different soil series to allow for dif• fering interpretations for use and management. Because the inherent phy ical properties of each till unit are different, it was necessary to identify and map a separate catena f soil series for each glacial till. Most of the soils formed in the Des Moines Lobe till have a fine•loamy particle size. These soi ls are in the Swanlake, Ves, Lester, Nicollet, ormania, Canisteo and Web• ter series. Most of the soi ls formed in Wadena L be till have a

coarse•loamy particle ize. These soils are in the Sunburg, Wadenil, Koronis and Grovecity series. ln the Kandiyohi till, most of the soils have a fine particle size. These soils are in the Arkton, Guckeen, Ki lkenny, Marna and Brownton series.

Soil science and soil survey mapping are closely related to

geomoq hology and geology. To better understand variations in soil serie , one must understand their differences in geological formation . However, it is not within the scope of, nor intent of, this report to present the complete geomorphology of these tills. The authors have identified and characterized differences in the nature and properties of the three major glacial till hodie. in Kandi yohi County, based on Soil Survey information and engineering test data. Mnny questions still exist a to the

Journal of, Vdume Forcy•nine, o. I, 1983/ 84

stratigraphic relationship of these three ti lls. I the Kandiyohi till a "pre•Wisconsin" till? Was the Alexandria Moraine covered by ice from the Des Moines Lobe? These uestions merit further tudy. Meanll'hile, differentiation of "Knndiyohi" till is a

sign ifirnnt step toward gremer understanding of the geomor• phology nnd geology of this part of the glacimed area of Min• nesota.

REFERENCES I. Marsch, Charle L. 1972. Quaternary geology of south•

western Minnesota. ln P.K Sims and G.B. Morey (ed.) Geology of Minnesota: A Centennial Volume. pp. 548-560. Minnesota Geological Survey, St. Paul, MN.

2. Wright, H.E., Jr., 1962. Role of the Wadena lobe in the Wisconsin glaciation of Minnesota: Geo!. Society America Bull., V. 73.100.

3. Wright, H.E., Jr., 1972. Quaternary history of Minnesota. In P.K. Sims and G.B. Morey (ed.) Geology of Minnesota: A Centennial Volume. pp. 5l5•547. Minnesota Geological Survey, Sc. Paul, MN.

4. Wright, H .E., Jr., 1972. Physiography of Minnesota. ln P.K. Sims and G.B. Morey (ed.) Geology of Minnesota: A Ceo• tennial Volume. pp. 561•578. Minnesota Geological Sur• vey, St. Paul, MN.

5. Crum, J.R. 1983. Personal communication. 6. Soil Conservation Service. 1972. Soil survey laboratory

methods and procedures for collecting soil samples. Soil Survey Investigations Report o . 1. U.S. Dept . Agr. Soil Conservation Service, Washington, D .C. 66 pp.

7. Allison, LE. and C.D. Moodie. 1965. Carbonate. In C.A. Black et al. (ed.) Methods of Soil Analysis, part 2. Agron. 9:1379-1396. Am. Soc. of Agron., Madison, WI.

8. The Asphalt Institute. 1978. Soils manual for the design of asphalt pavement structures. Manual Series no. 10, Asphalt Institute Building, College Park, Maryland. 238 pp.

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