Abstracts with Programs - Geological Society of America

as geology, ecology, biology, and resource conservation. With such a wide variety of educational
opportunities, this ecosystem brings together students and researchers from many branches of
science.
This study was conducted as a service learning project to collect diatom samples from Glen
Helen, to relate the diatom species to water chemistry data, and to provide teaching materials for
the numerous education activities taking place in Glen Helen. Permanent slides will be made from
samples collected from water, macrophytes, and sediments. Diatoms will be identified, sketched,
and photographed to develop a teaching set of diatom identification for the Glen Helen area that
will be published as a handbook for use in the Glen Helen educational activities. The diatoms
will provide an additional layer of data to complement the ongoing water chemistry study being
conducted by Wright State University and Antioch College students.
28-19 BTH 19 Brinkmann, Sarah [218522]
DIATOM COMMUNITIES NEAR ACID MINE DRAINAGE AT GREEN VALLEY LAKE, WEST
TERRE HAUTE, INDIANA
BRINKMANN, Sarah, BRAKE, Sandra S., and STONE, Jeffery, Department of Earth and
Environmental Systems, Indiana State University, Terre Haute, IN 47809, sbrinkmann@
sycamores.indstate.edu
Green Valley Lake is located in West Terre Haute, Indiana, near an abandoned coal mine. Acid
mine drainage (AMD) leaching from the site of the abandoned mine has impacted this area for
almost 55 years. Seasonally, the pH of effluent streams drops as low as 3 in some areas. Elevated
levels of SO , Fe, Al, and heavy metals occur in streams (and groundwater) that may contaminate
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Green Valley Lake.
Diatoms are a golden-brown algae with a siliceous skeleton; they are an important primary
producers that are abundant and typically well-preserved as fossils in most lake systems. To
explore the environmental impact of AMD on this system, we sampled the lake plankton and
sediments for fossil diatoms, which are known to be highly sensitive to acidity in lakes and
streams. The purpose of this study is to analyze the spatial distribution of diatoms in the lake and
sediments. Samples were collected from the plankton and sediment from 11 locations around
the lake. Our hypothesis is that diatom diversity should increase away from areas of riverine
discharge into the lake. Results from this study will help determine how AMD has influenced
the structure of the diatom community in the lake and provide a baseline measurement for the
modern lake system so that the long-term resilience of these communities can be analyzed in
future studies.
28-20 BTH 20 Smart, Saundra M. [218589]
INFLUENCE OF DIATOM DIVERSITY IN AN INDIANA STREAM IMPACTED BY ACID MINE
DRAINAGE
SMART, Saundra M., STONE, Jeffery, and BRAKE, Sandra S., Department of Earth
and Environmental Systems, Indiana State University, Terre Haute, IN 47809, ssmart1@
sycamores.indstate.edu
Acid mine drainage (AMD) associated with the abandoned Green Valley coal mine site in West
Terre Haute, IN, discharges into West Little Sugar Creek (WLSC), a nearby natural stream.
The area has been impacted by AMD for nearly 55 years, denoting WLSC as one of Indiana’s
most contaminated water systems. Despite various remedial efforts, AMD still discharges into
WLSC, where pH drops to as low as 3. The acidic effluent and stream water contains elevated
concentrations of SO , Fe, Al, and trace elements, many of which exceed state and federal
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surface water quality standards. Local aquatic life is adversely impacted by the high acidity and
high concentrations of dissolved constituents. Downstream of the mines site, metal concentrations
decrease and pH increases due to dilution from surface water runoff and groundwater discharge
into the stream.
To assess the environmental impact of AMD on the ecology of the WLSC stream system, this
study evaluates changes in diatom species upstream and downstream of the discharge zone.
Diatoms were selected because of their abundance in most water systems, high diversification,
and siliceous frustules, the latter of which is often preserved in sediment. Diatoms are known
to be highly sensitive to environmental changes, such as toxic metal concentrations and acidity.
We hypothesize that the low pH and highly toxic conditions of WLSC will decrease species
diversification downstream. Specifically, we examine changes in riverine diatom communities
downstream from the discharge site to determine how far downstream the influence of acid
mine drainage persists and to establish a baseline for seasonal fluctuations to help evaluate the
resilience of these communities.
28-21 BTH 21 Burns, Anastasia Marie [218664]
EVALUATION OF FACTORS INFLUENCING NITRATE CONCENTRATIONS IN GROUNDWATER
IN EAU CLAIRE COUNTY
BURNS, Anastasia Marie, UW-Eau Claire, 1824 1/2 Brackett Ave, Eau Claire, WI 54701,
burnsam@uwec.edu and GROTE, Katherine R., Geology, University of Wisconsin-Eau
Claire, 105 Garfield Ave, Eau Claire, WI 54702
In Eau Claire County, about 6.4% of private wells have nitrate concentrations exceeding
the Enforcement Standard (ES) of 10 mg/L. This project investigates whether high nitrate
concentrations can be correlated to geologic and hydrologic parameters or to land management.
If such correlations are found, they can be used to develop a risk assessment map for Eau Claire
County that could be used to predict areas that are at an elevated risk for nitrate contamination.
To aid in this study, the Eau Claire County Health Department provided nearly 6,000 nitrate
concentrations from groundwater samples acquired in private wells over a period from 1999 to
2004 and again from 2005 to 2009. Using GIS, these data sets were joined to maps of depth
to bedrock, depth to water table, soil texture, soil taxonomy, geomorphology, and land use. The
resulting data sets enabled correlations to be made between these parameters and nitrate
concentrations, and to observe how these correlations changed with time between the two data
sets. The factors which appeared to have the most impact on nitrate concentrations were land
use, depth to the water table, and depth to bedrock. Agricultural land typically had the highest
nitrate values, although the nitrate concentrations in urban areas increased significantly with time.
Areas with higher bedrock tended to have higher nitrate values, while areas with shallow water
tables had lower average nitrate values.
To better investigate the factors controlling nitrate contamination, combinations of factors that
independently appeared to influence nitrate concentration were considered. These analyses
helped to show which combinations of natural and anthropogenic conditions were most likely
to result in high nitrate concentrations. Although analysis of different combinations of factors is
ongoing, the areas which seem most likely to have high nitrate concentrations are rural areas with
intermediate water tables (5-50 ft beneath the surface), highly developed (more urban) areas with
shallow bedrock, and areas with both shallow bedrock and shallow water tables.
SESSION NO. 28
28-22 BTH 22 Peters, Carl E. [218462]
GEOCHEMICAL ANALYSIS OF HEAVY METALS IN SEDIMENTS SURROUNDING THE
BAUTSCH-GRAY MINE SUPERFUND SITE, JO DAVIESS COUNTY, ILLINOIS
PETERS, Carl E., Geology Department, Augustana College, 639 38th Street, Rock Island, IL
61201, carlpeters09@augustana.edu
Mining operations at the Bautsch-Gray lead mine site, located near Galena, IL, for the last
eighty-six years have resulted in elevated levels of lead, zinc, and arsenic within the surface
materials surrounding the mine property. Although remediation began in September of 2010
with the removal of 2600 m3 of contaminated soil from the mine site and neighboring residential
properties, there has been continued migration of mine tailings. This has prompted a need to
better understand the extent of contamination in the properties surrounding the mine tailings,
at depth, and within particle sizes of mine tailings. A total of 29 surface soil samples, six depth
samples, and two grain size analysis samples were taken from properties west, northeast,
north, and south of the mine site. Samples were analyzed for heavy-metal contamination with an
X-Ray Fluorescence spectrometer (XRF). Of the 29 surface samples, three samples exceeded
Environmental Protection Agency (EPA) regulatory limits for heavy-metals in soils, and 24
samples exceeded background levels for heavy-metals. The highest concentrations of lead, zinc,
and arsenic contamination were measured at 510ppm, 3024ppm, and 100ppm respectively.
No migration of heavy-metals was seen to occur downward through the soil profile, suggesting
that transportation of contaminants is occurring primarily due to runoff directly from the mine
tailings. From this research it was determined that heavy-metals have continued to migrate into
the properties west and north of the mine, with lead, zinc, and arsenic levels still exceeding EPA
regulatory limits and background levels.
28-23 BTH 23 Krehel, Austin W. [218634]
WIND STEERING AND SEDIMENT TRANSFER ASSOCIATED WITH STORMS IN A BLOWOUT
DUNE AT SAUGATUCK HARBOR NATURAL AREA, MICHIGAN
KREHEL, Austin W., Geological and Environmental Sciences, Hope College, Holland,
MI 49423, austin.krehel@hope.edu, YURK, Brian, Department of Mathematics, Hope
College, PO Box 9000, Holland, MI 49422-9000, and HANSEN, Edward C., Geological and
Environmental Sciences, Hope College, 35 E 12th Street, Holland, MI 49423
The effects of 8 extratropical cyclones on wind directions, wind speeds, sand erosion, and
sand deposition were studied in a blowout dune in the Saugatuck Harbor Natural Area on the
southeastern shore of Lake Michigan during Fall, 2010 and Spring and Fall, 2011. The blowout
is on the limb of a parabolic dune isolated from the beach by an established foredune ridge. It is
53m long, 8 m high, SE trending and opens to the northwest with two notches on the western
limb. Wind speeds and directions were measured with anemometers and wind vanes at 6 different
localities within the dune while erosion and deposition were measured with an array of 211 pins.
Regional wind directions at a high angle (E, NE, S, SSW) to the opening of the dune, led to
bifurcated flow of relatively low velocity winds within the trough, which can sweep sand out of the
trough and deposit it in the northwest notch. Regional winds at a lower angle to the dune opening
(WSW, W, NW, N), were steered up the axis of the trough with the loss of wind energy increasing
with increasing steering angle. These winds are associated with erosion along the trough axis
and deposition on the southern outer slope. Winds with a strong westerly component are also
funneled through the notches leading to scoring along the inner limbs of the dune and deposition
within the trough and eastern outer limb. The exact response of a dune to a given storm is the
result of a complex interplay between wind direction, which depends on cyclone track, and local
topography.
28-24 BTH 24 Salzwedel, Mitchell [218651]
THE EFFECT OF LONG-TERM LAND USE CHANGES ON SOIL ORGANIC CARBON IN
SOUTHERN WISCONSIN
SALZWEDEL, Mitchell and DOLLIVER, Holly A.S., Department of Plant and Earth Science,
University of Wisconsin-River Falls, 410 S. 3rd St, River Falls, WI 54022, mitchell.salzwedel@
my.uwrf.edu
Transformation of undisturbed Wisconsin prairies to agricultural soils has resulted in a loss
of soil carbon. Tillage of agricultural soils exposes soil organic matter (SOM) to oxygen, and
the carbon in SOM will oxidize to the atmosphere. Soil carbon greatly improves the physical,
chemical, and biological properties of the soil. Equally as important, carbon locked in the
soil does not impact carbon concentrations in the atmosphere, which contributes to global
climate change. The objective of the study was to quantify the amount of organic carbon in
undisturbed versus agricultural soils. A total of six paired sites were selected for this research.
Undisturbed soils were classified as areas that have not been disturbed for 50+ years. In all cases
disturbed and undisturbed areas were less than 100 meters apart and sampled at three depth
intervals: 0-10 cm, 10-40 cm, 40-100 cm. Total organic carbon was on average 44.3% lower in
agricultural versus undisturbed soils. Data from the depth intervals also shows that differences
in carbon concentrations between undisturbed and agricultural soils were most significant in the
40-100 cm interval (57% higher in undisturbed) compared to the 0-10 cm interval (22% higher
in undisturbed). This data supports that a tremendous amount of carbon has been lost to the
atmosphere due to land use conversion.
28-25 BTH 25 Hein, Jordan A. [218760]
QUANTIFYING BANK EROSION AND CHANNEL SEDIMENTATION ON THE TORCH, RAPID
AND GRASS RIVERS IN NORTHERN LOWER MICHIGAN
HEIN, Jordan A. 1 , KENDALL, Anthony D. 2 , and BUDD, Blaze M. 2 , (1) Department of
Geological Sciences, Michigan State University, 206 Natural Science Building, East Lansing,
MI 48823, heinjord@msu.edu, (2) Department of Geological Sciences, Michigan State
University, 206 Natural Sciences Bldg, Michigan State University, East Lansing, MI 48824
Rapid sedimentation and bank erosion have steadily reduced the navigability of the rivers in the
Chain of Lakes watershed in Northern Lower Michigan during the last several decades. Historical
documentation indicates that these rivers were once deep enough for steamboat travel, but now
are all but impassable by even shallow draft watercraft. Beyond the navigational issues presented
by sedimentation, bank erosion threatens property and water access. This study focuses on three
rivers: the Torch, the Rapid, and the Grass. Each of these rivers have been affected by dramatic
anthropogenic changes during the last 150 years, including extensive land cover change, channel
modification, and base level changes via damming the terminal lake on the Chain.
Here we present work that quantifies bank erosion over the last eight decades via aerial
and satellite imagery analysis, along with the current channel bottom depths via bathymetric
measurements. This work demonstrates that significant changes have occurred, and continue to
occur, to bank positions. Sections of the river with the most bank change are also the shallowest,
indicating that the channel continues to evolve toward a new dynamic equilibrium. We illustrate
how sections with the least change are those that have had the most active management, and
2013 GSA North-Central Section Meeting 63