GEOGRAPHY OF SOILS AND GLACIAL GEOLOGY COMBINED …pfarrell/Soils/Field Trip HAndout 2017.doc  · Web viewAll soils developed on the same parent material (outwash), are of the same

REMINDERS FOR 2018 FIELD TRIP: BRING WATER JUGS TO FILL WATER BOTTLES FOR DRINKINGCHECK FOR SPARE TIRES ON VEHICLESBRING BIRD BOOK

GEOGRAPHY OF SOILS FIELD TRIP

DAY ONELearning Objectives:

1. Observe changes in soils along a slope transect (catena).2. Learn and gain practice in soil description and observation procedures, including new ones: pH, horizon boundaries, horizon and subhorizon designations.3. Learn how peat bogs form and how to describe and sample an organic (peat bog) sample.4. Observe landscapes (glacial lakes, moraines, outwash)

FIGURE ONE

First Soil Stop: CLOQUET FORESTRY CENTER (30 minute drive)

Materials needed:Field trip handout, lab book, pencil, and soil equipment: shovel, pH kit, compass, clinometer, spray bottles, distilled water, sand chart, hand lens, Munsell color chart, acid bottle, measuring tape, rags, GPS, sampling bags, Sharpies.

Cloquet Forestry Center 46°42’13”N, 92°3’26”W is located on deposits from the Superior Lobe of the ice sheet. The soil pits that we will be examining are in outwash deposits. (See Figure One). Outwash is sand and gravel that was deposited by meltwater from an ice sheet.

We will examine soil in four pits. All soils developed on the same parent material (outwash), are of the same age, have the same vegetation cover and have the same climate. The only difference in the four pits is their location on the slope and their proximity to the water table. The water table gets progressively higher in the soil profile as we move downslope. The summit position is high and dry, above the water table. The lowest slope position is sometimes inundated with water because it is at, or just above, the water table. If you continue down the slope, you will see a sphagnum bog. We have a catena of soils here, in four soil pits located along a slope.

ASSIGNMENT:Working in groups, choose a soil pit and slope position for your group. Choose one person to neatly record observations on a Soil Profile Description Sheet. Begin by completing the top of the sheet with general site information and be sure to include the slope position (summit, backslope, etc). For slope aspect, take the compass bearing from your site to the next lower site. Get a clinometer reading from the next lower site back to your site to get slope angle, if your site is on a sloping surface.

Clean one face of the soil pit with a shovel so that you can clearly see all of the horizons in the profile. Examine each different layer carefully. Whenever you see any kind of change in color, texture, structure, make it a new horizon/subhorizon, even if you are not sure of the letters to use. Follow the instructions in your lab book from the Field Observation and Soil Description Lab to describe soil properties and to name horizons and subhorizons. For each subhorizon, record the depth (e.g., 13 – 24 cm) and describe each soil property on the Soil Profile Description sheet.

Take a sample from each subhorizon. Label sample bags (with initials of group members, date, location, slope position, depth of sample, (e.g., 13-24 cm) . Sample size should be approximately 1 cup.

For pH determinations, carefully follow instructions with the meter and be sure to use DISTILLED water only. Before each new set of readings, be sure to calibrate the meter, as indicated in the instructions.

After you complete your soil profile information for your site, be sure to walk to each of the three other sites and observe the soils there, without doing the description.At our meeting at Itasca at the end of the day, you can exchange site information with all other class members, including the other members of your group. examine our description sheets and share profile information.

Each of you should answer the questions below for your Lab report on the field trip.

For Lab Report:A. Questions:1. What are the main differences that you observed in the soils described by your classmates for the four sites? Consider qualities such as: A horizon thickness, color of the surface horizon, changes in texture, changes in chroma values, presence or absence in RMF’s (redoximorphic features), significant changes in soil pH in the profiles?

2. For each of those differences, give an explanation.

B. Slope Profile: Use the information you collected from the field trip to draw a slope profile of the catena sequence. In your drawing, include a profile drawing of each soil pit site.

Second Soil Stop: PEAT BOG IN LAKE PLAIN OF GLACIAL LAKES AITKIN AND UPHAM (45 minute drive)

FIGURE TWO

Figure Two shows the extensive area in northern MN covered by the lake plain of these former glacial lakes. The resulting landscape is FLAT and poorly drained. Glacial Lakes Aitkin and Upham: Glacial history in

this region of MN is complex. Several advances from different lobes of the Laurentide Ice Sheet (Wadena, Rainy, Superior and Des Moines Lobes of ice) moved through this region. See Figure Three.

FIGURE THREE

Each lobe in each advance deposited moraines. One of the advances of the Superior Lobe left the Highland and the Mille Lacs moraines. The Highland moraine acted as a dam and water was ponded to form Glacial Lakes Upham I and Aitkin I. Later, the St. Louis sublobe (of the Des Moines Lobe) stagnated and Glacial Lakes Upham II and AitkinII formed . These lakes covered an extensive area of northeastern Minnesota. (See Figures Four and Five).

The lakes stood at several levels, and formed strandlines (beaches) at each level. The lake water also modified earlier deposits of till. On our drive to Floodwood and Jacobson, we traverse Upham and Aitkin beaches and wave-washed tills from this basin. Eventually, the lakes drained through St. Louis River around 9000 yrs. BP. You will notice numerous peat deposits on the lake plain, where closed depressions have filled with peat.

FIGURES FOUR AND FIVE

Peat Bog : Peat forms when organic material accumulates more rapidly than it is decomposed. These old, glacial lake basins are very flat and therefore very poorly drained. The wetness encourages anaerobic decomposition, which is relatively slow and not as efficient as aerobic decomposition. This slow decomposition rate has allowed organic deposits to accumulate here for thousands of years, creating deep, peat soils.

We will examine a core of peat from one of these closed depressions in the Arlberg bog. This peatland extends over 8900 acres. The peat soil here consists of 5-6 meters of peat above very fine sand of glacial lake origin. These soils have extremely low bulk densities (0.2 – 0.3 g/cm3) and high porosity (80%). The minerals in organic soils are tied up in organic compounds and are not plant-available, therefore only very specialized plants grow in peat bogs. Look for Black Spruce (Picea mariana), Labrador tea (Rhododendron groenlandicum), dwarf shrubs like blueberry (Vaccinium spp.), leather leaf , Sphagnum moss and Hypnum moss.

Important descriptive elements of organic soils are the botanical origin of the organic material (sphagnum, grasses, sedges, cattails, wood and leaf litter) and the extent of decomposition. A simple classification is:

Fibric (peat) <1/3 decomposed; >2/3 identifiable (Von Post H1 – H4)Hemic (mucky peat or peaty muck) moderately decomposed (Von Post H5 –H6)Sapric (muck) 2/3 decomposed; <1/3 identifiable (Von Post H7-H10)

A more detailed classification is given in the Von Post method (below). We will examine a core and use the Von Post method.

Materials: rags, peat sampler and handle and extension, field trip handout for taking notes, bulk density sampler, six sampling bags and marker, GPS.

Assignment:Learn the Von Post and simple (fibric, hemic, sapric) classification of peat. Take two samples (total for class) for bulk density, two samples for water content, and two samples for organic matter content (to be analyzed in later laboratory exercises). Label the bags with initials, date, site (“Arlberg Peat Bog”), depth of sample (e.g., 13 – 24 cm) , sample number and test that sample is collected for (e.g., bulk density sample 1, bulk density sample 2)

THE VON POST SCALE OF HUMIFICATION (source Ekono 1981)

Symbol Description

H1 Completely undecomposed peat which, when squeezed, releases almost clear water. Plant remains easily identifiable. No amorphous material present.

H2 Almost entirely undecomposed peat which, when squeezed, releases clear or yellowish water. Plant remains still easily identifiable. No amorphous material present.

H3 Very slightly decomposed peat which, when squeezed, releases muddy brown water, but from which no peat passes between the fingers. Plant remains still identifiable, and no amorphous material present.

H4 Slightly decomposed peat which, when squeezed, releases very muddy dark water. No peat is passed between the fingers but the plant remains are slightly pasty and have lost some of their identifiable features.

H5 Moderately decomposed peat which, when squeezed, releases very “muddy” water with a very small amount of amorphous granular peat escaping between the fingers. The structure of the plant remains is quite indistinct although it is still possible to recognize certain features. The residue is very pasty.

H6 Moderately highly decomposed peat with a very indistict plant structure. When squeezed, about one-third of the peat escapes between the fingers. The residue is very pasty but shows the plant structure more distinctly than before squeezing.

H7 Highly decomposed peat. Contains a lot of amorphous material with very faintly recognizable plant structure. When squeezed, about one-half of the peat escapes between the fingers. The water, if any is released, is very dark and almost pasty.

H8 Very highly decomposed peat with a large quantity of amorphous material and very indistinct plant structure. When squeezed, about two-thirds of the peat escapes between the fingers. A small quantity of pasty water may be released. The plant material remaining in the hand consists of residues such as roots and fibres that resist decomposition.

H9 Practically fully decomposed peat in which there is hardly any recognizable plant structure. When squeezed it is a fairly uniform paste.

H10 Completely decomposed peat with no discernible plant structure. When squeezed, all the wet peat escapes between the fingers.

B1 Dry peat

B2 Low moisture content

B3 Moderate moisture content

B4 High moisture content

B5 Very high moisture contentNote: The moisture regime of each peat sample is estimated using the above scale of 1-5 and symbol “B” (derived from Swedish blöthet = wetness).

Proceed to Continental Divide and JacobsonWe will proceed to Jacobson by continuing west on Highway 2, then turning onto Route 200. At approximately 4 miles after we turn left on 200 (around Mile Marker 197), we cross a continental divide between Great Lakes drainage and Mississippi drainage.

FIGURE SIX

DRIVE to Itasca State Park, UNIVERSITY OF MINNESOTA FIELD STATION : (about 2.5 hours)

THINGS TO NOTICE ABOUT THE LANDSCAPE AS WE DRIVE TOWARDS HILL CITY:

As we drive west, we continue through the expansive, flat lake basin. The peat bogs are evident by the expanses of black spruce trees which look like dead trees, but are actually alive and well. Eventually we approach Hill City, presumably so-named because of the relatively high relief in the Des Moines Lobe end moraine, the “Sugar Hills Moraine”,

in which Hill City lies. (See Figure Five).This high relief topography(steep hills with bogs or lakes between the hills) is typical of an end moraine landscape.

We enter Leech Lake Reservation before the town of Remer (home of Big Foot?????). You will notice Leech Lake on your right. As we drive, you can observe the rocky moraine landscape. We will pass the Northern Lights casino, one of three casinos operated by the reservation. Before we get to Itasca State Park, on Rte. 71, you can observe the large enclosed pile of pipeline pipes, waiting to be installed if the proposed new pipeline is approved by the Public Utilities Commission.

ITASCA STATE PARK

Itasca is the oldest state park in Minnesota. The park was established in 1891 to protect the drainage basin around the source of the Mississippi River (Lake Itasca) and virgin stands of red and white pine, 100-300 years old. Hunters were here 8500 years ago; the Dakota people were here 3000-350 years ago and the Ojibwe were here from approximately 300 ? years ago to today. The park used to be called Omushkos, the Ojibwe word for “elk”. The first white explorer called it Itasca as a combination of “veritas” and “caput”, Latin for “true head”. We will look at some interesting things in the park, including the headwaters of the Mississippi. Ozawindib, an Ojibwe guide brought Henry Schoolcraft to the headwaters in 1832 Mississippi Facts:

The Mississippi River flows 2,340 miles from Lake Itasca to the Gulf of Mexico.

The first 50 miles, navigable only by canoe, are the last vestige of the wild Mississippi.

It takes a raindrop approximately 90 days to travel from Lake Itasca to the Gulf of Mexico.

The river's watershed drains 41 percent of the continental United States, or between 1.2 and 1.8 million square miles.

Most of Itasca State Park is in the Itasca Moraine, an end moraine of the Wadena Lobe of ice.

DAY TWOLearning Objectives: 1. Learn about Glacial Lake Agassiz and the extensive lake plain landscape. Observe these lake clay soils.

2. Observe the extensive agricultural ditching of this region of Minnesota, draining what would otherwise be wetlands. 3. Observe and learn about the sugar beet harvest.4. Visit a beach ridge of Glacial Lake Agassiz and learn about beach ridge formation.5. Study the soil signature of a native grassland and describe a grassland soil. Practice soil description skills.6. Observe the characteristics of a typical forest soil.7. Learn the differences in till from lobes of ice with differing provenances.

FIRST STOP: Glacial Lake Agassiz clays near Ada, MN (Drive about 1.5 hours from Itasca)

After leaving Itasca, about 6-7 miles west of the Park Entrance, on Highway 71/200, we cross another Continental Divide (around mile marker 76-78), separating the Mississippi drainage from the Red River drainage.

As we leave Itasca and drive west towards Ada, we will pass through Wadena Lobe moraine deposits and then Des Moines Lobe moraine. As we approach Ada, you will notice the end of the hilly moraine landscape and the beginning of a vast, flat landscape, the lake plain of Glacial Lake Agassiz. See Figure SEVEN below. FIGURE SEVEN

Glacial Lake Agassiz was formed as the retreating ice, towards the end of the Wisconsin glaciation, blocked the northward flowing drainage towards Hudson Bay. During this time, the lake had multiple stages and multiple outlets. The maximum extent of this enormous lake is shown in Figure Eight below. The lake existed, in various sizes from 11,700 – 9400 years ago. Lake of the Woods and the Upper and Lower Red Lakes are remnants of this ancient, huge lake.

11,700 years ago, the Des Moines Lobe of ice melted back north of the continental divide, trapping meltwater between the ice to the north and the moraines to the south. The lake got deep enough to overtop the glacial till and cut a valley which is now occupied by Big Stone Lake.

Ada

FIGURE EIGHT

LAKE CLAY:In the former lake bed of this enormous lake, we can see deep lacustrine sediment of Glacial Lake Agassiz. Locally, these clayey soils are called “gumbo soils” because they are very sticky and gummy when wet. During dry periods, they dry out and develop deep cracks.

The lake sediments themselves form Vertisols in deep deposits of silty clay. The lake plain itself is extremely flat, with relief in some places only one inch per mile. Ditching in this region can be seen on the topo maps. Ditches remove water from the surface, which has led to productive agriculture, especially of sugar beets and small grains. But the ditching has increased peak flows to the Red River and may be partly responsible for severe flooding in recent years.

MATERIALS: Materials needed:

Field trip handout, lab book, pencil, and soil equipment for two groups: two shovels, two augers, spray bottles, distilled water, sand chart, hand lens, Munsell color chart, acid bottle, measuring tape, rags, GPS, sampling bags, Sharpies.. ASSIGNMENT: Working in two groups, auger as deep as you are able in this sticky clay soil and fill troughs to do a soil description. Remember to keep track of the depths using the auger hole. Record observations on a Soil Profile Description sheet.

Take samples of each horizon for later laboratory analysis.

SECOND STOP: Beach Ridge, Twin Valley Prairie(30 minute drive from Ada)

As the ice retreated North, the lake covered the land. As the ice advanced and retreated over several hundred years, the water level in the lake varied. At each constant level of the lake, beaches, sand spits and sand bars developed on the shore and near shore, just as they do in modern-day lakes. The waves of the lakes were moving and depositing moraine (till) deposits so the beaches are composed of sand and gravel. The beaches of this enormous lake are about 500 feet wide but only about 10-15 feet high. Today, they remain as very subtle rises on an otherwise very flat landscape, but the deposits in these subtle rises differ significantly from their surroundings.

The four major beaches in Minnesota of Glacial Lake Agassiz are :Herman Beach (the oldest) at elevation of 1,075 feet (formed about 12,000 years ago) Norcross Beach at elevation 1,040 ftTintah Beach at elevation 1,020 ftCampbell Beach at elevation 981 ft.

Dotted lines on the map below represent beach ridges.

FIGURE NINE

Twin Valley Prairie is a Nature Conservancy Preserve of 499 acres on a prominent beach ridge. The site is an important staging area for sandhill cranes. The site is considered a “biodiversity hotspot” because it contains species of both dry and wet prairies. According to the Nature Conservancy’s website, the “site was selected because it contains many of the plant communities found in abundance prior to agricultural expansion in northwestern Minnesota. The site has a narrow band of dry prairie only yards away from bulrush and cattail marshes, meeting the habitat needs of a wide variety of plant, insect and bird species… the Conservancy has reclaimed a former gravel pit, reseeded a portion of the preserve, that was formerly farmed, to native prairie species and removed numerous mature trees…Tree rows in the midst of open prairie provide habitat for predators such as raccoons, skunks and birds of prey, which can diminish the ability of grassland birds to successfully nest”.

We will observe the gravel and sand deposits in this beach ridge, without digging. Digging is prohibited in Scientific and Natural Areas (SNAs) without special permission.

Lunch at Ulen Wayside (15 minute drive from prairie)(Here we are able to examine Agassiz clay in the bank of Wild Rice River, a tributary of the Red River).

STOP THREE: PRAIRIE SOIL

(25 MINUTE DRIVE FROM Lunch Stop)

The remaining three stops on our field trip will look at the effect of vegetation on soils. We will study a prairie soil, a transitional soil, and a forest soil. All three of these soils we will see have the same parent material: Des Moines Lobe till. The differences that you will see in these three soils are due to vegetation changes.

There are many theories attempting to explain the abrupt transition in Minnesota from forest to prairie. These theories range from climate change to fire patterns to changes in topography. Prairie and forest vegetation have existed in Minnesota since the Pleistocene glaciation. The prairie/forest transition was very dynamic and ever-changing before European settlement. The changing border was dictated by the frequency and severity of fires and weather patterns. Several different kinds of communities existed along this transition zone, including brush prairie and savanna. (See Figure Ten).

Before settlement, the “Big Woods” (deciduous forest) , existing south and west of the Twin Cities, covered over 2 million acres in Minnesota. Currently the remaining acreage of the Big Woods is mainly comprised of the late-successional species of maple and basswood referred to as maple-basswood forest. The first trees to invade the prairies were oak, aspen and willow, followed later by elm.

Fires started by lightning and by American Indians were originally the primary obstacles to forest invasion into the prairie. Frequent fires spread easily over the prairie, killing most invading trees and shrubs, but were extinguished when they reached the moister forest regions. The prairie grasses would quickly regenerate after the burns. The large burr oaks were resistant to fire, and the willow and aspen regenerated quickly after burns at the transition. A later shift in climate to cooler, wetter conditions in the Big Woods likely ushered in the shift from oak and aspen to elm.

FIGURE TEN

Settlement of the transition area brought with it extensive fire control to protect buildings, crops, livestock, and the surrounding woodlands. Constructed railroads and highways served as fire breaks. This fire suppression has and continues to lead to the invasion of the forest into the remaining native prairie lands. Prescribed burning is now used to manage the remaining native prairies.

Prairie vegetation dominates landscapes to the west on Des Moines lobe ground moraine, which has relatively low relief. Here the landscape is complex and consists of beach ridges, inter-ridge complexes and lacustrine sediments. The topographically higher landscapes are dominated by forests and are composed of Itasca End Moraine (from the Wadena Lobe) and the Big Stone Stagnation Moraine (from the Des Moines Lobe).

ASSIGNMENT: The prairie soil that we will look at is a Mollisol, with the typical deep, dark, mollic epipedon (a HORIZON) characteristic of grassland soils. Working in groups, we will describe a prairie soil here.

MATERIALS: Field trip handout, lab book, pencil, and soil equipment: shovels, augers and extensions and couplings, soil troughs, pH kit, spray bottles, distilled water, sand chart, hand lens, Munsell color

chart, acid bottle, measuring tape, rags, GPS, sampling bags and markers.

ASSIGNMENT: Working in 2 groups, describe the prairie soil. Auger as deeply as you possibly can and fill troughs with your soil, keeping track of true depths by measuring the hole. Complete a soil profile description sheet for your group. Notice the deep A horizon and look very carefully for any changes in color, texture, structure that you can see as you auger, that may indicate a change in horizon/subhorizon. Take a sample from each subhorizon. Label the bags with your initials, date, site, and depth, e.g., 13-24 cm.

STOP FIVE: FOREST SOIL (ALFISOL) IN DES MOINES LOBE DEPOSIT (short drive)This alfisol formed in a forest in an area that has been dominated by forest vegetation for thousands of years. Note all the features of this soil that make it a forest soil: shallow A horizon, weak E horizon, Bt argillic horizon.

MATERIALS: shovel, Munsell, acid bottle, sand chart, hand lens, spray bottles

ASSIGNMENT: We will complete a Soil Profile Description sheet together as a class. Everyone should complete a sheet as we go through this exercise.

Return to Itasca State Park. (1 hour drive)

DAY THREELearning Objectives:

1. Compare Des Moines lobe till and Wadena lobe till due to their provenances. 2. Learn about the formation of drumlins and observe drumlins in the Wadena drumlin field.3. Do a catena study on the side of a drumlin, observing differences due to slope position and proximity to the water table.

STOP ONE: A DRIVING TOUR OF THE DRUMLIN FIELD(1.5 hour drive from Itasca)The Wadena drumlin field is in the Wadena lobe till. The provenance (or origin) of the Wadena Lobe is the Hudson Bay area of Canada. The stones in the Wadena till are limestone and granite. The till color is buff to yellowish brown and is coarse-textured with a lot of stones and boulders in it. The Des Moines Lobe had a provenance slightly west of the Wadena Lobe in Canada and contains shale in addition to limestone and granite. It is a more fine textured till with few boulders and a buff to yellowish brown color.

Drumlins are elongated hills of glacial till, like upside-down spoons, that form under the ice sheet and always occur in swarms, rather than as isolated individual hills. (See Figure Eleven). There are approximately 1200 drumlins in the Wadena drumlin field. The moving ice plastered the underlying sediment into these features. They are quite evident on the topographic map. The long axes of drumlins are oriented in the direction of ice movement, with the less steep side of the drumlin pointing in the direction of ice movement.

FIGURE ELEVEN

FIGURE TWELVE

FIGURE THIRTEEN

STOP TWO: Catena Study on the side of a drumlin (Ron and Sue Storbakken’s farm)The drumlins in the field we are visiting are composed of loose material that has been plastered into a very compact core. The bulk density of the core is very high, 1.9 – 2.0 g/ml. (For comparison, loamy soils have a bulk density of 1.1 – 1.5; concrete has a bulk density of 2.4). The core is encountered at approximately 4 – 5 feet below the surface (depth of frost). The core is so dense that it prohibits water penetration and creates a perched (raised) water table. In the spring, water seeps out of the side of the drumlin from this water table. The depth of redoximorphic features tells where the water is concentrated in the soil. We will examine a catena of soils on the slope of a drumlin. Moving downslope, the redox features are closer to the surface, the sediment becomes increasingly moist, and the texture changes because clay is moving downslope.

Materials: Field trip handout, lab book, pencil, and soil equipment: shovel, augers and extensions, pH kit, compass, clinometer, spray bottles, distilled water, sand chart, hand lens, Munsell color chart, acid bottle, measuring tape, rags, GPS, sampling bags and markers.

ASSIGNMENT:

Working in four groups, collect cores from four topo positions on the side of the drumlin. Core as deeply as you can and describe the core using a Soil Profile Description Sheet. Place your core samples in soil troughs. After all sites have been described, we will compare the four sites. Use soil description sheets to record your results. Take samples from each subhorizon and label bags carefully.

When you do the Lab Report, answer the following questions:

1. What changes in A horizon thickness, color and texture did you observe in the profiles? To what do you attribute these changes?

2. What changes in chroma values did you observe in the subsurface horizons ofthe profiles and how do you explain these changes?

3. What redoximorphic features did you observe in the profiles? How can youexplain their presence, depth or absence in the various landscape positions?

Drive back to UMD (2 hours, 40 minute drive)