2014 Undergraduate Research Day

Floodplain Contamination Caused by Historical Lead Mining, Big River, SE Missouri

Liesel Benecke
Ozarks Environmental and Water Resource Institute & Biology
Faculty Advisor: Dr. Robert Pavlowsky

The Big River is located in southeastern Missouri and drains the Old Lead Belt, a historic lead (Pb) mining area which was a global producer of Pb worldwide from 1869 to 1972. Past and ongoing releases of mining wastes to the Big River have resulted in the contamination of floodplain deposits with toxic levels of Pb along 170 kilometers of the Big River from Leadwood, Missouri to its confluence with the Meramec River. This study links historical mining pollution sources to large-scale contamination of the Big River by evaluating the spatial patterns of Pb contamination in floodplain soils. X-ray Fluorescence and stratigraphic analysis of the <2mm sediment fraction was used to examine downstream trends and vertical profiles of Pb in floodplain cores. This study quantifies downstream trends of mining-related Pb contamination, evaluates the variations in background Pb levels within pre-mining aged sediments in comparison to contaminated sediments, and links specific mining areas to variations in Pb profiles in floodplain cores. The amount of Pb storage in floodplains along the Big River is extensive and may approach one-third of the Pb wastes produced in the Old Lead Belt.

Bank Erosion Assessment of Wilson Creek in Springfield, Missouri

Felix Corrodi
Geography, Geology, and Planning
Faculty Advisor: Dr. Robert Pavlowsky

Wilson Creek watershed has been affected by both urbanization and grazing agriculture which has destabilized the channel in several segments as indicated by eroding banks and incised channels. To address this problem, the City of Springfield and local watershed groups have partnered to rehabilitate riparian forest areas and stabilize eroding banks by fencing out cattle and planting trees. This study reports on a long-term study of bank stability along a segment of Wilson Creek where riparian improvements have occurred in order to monitor improvements in channel stability. Bank stability and channel form was assessed at 18 sites along a 1 km segment of Wilson Creek about 3 km downstream of the city limit. Geomorphic assessment and monitoring of the Wilson creek was conducted to estimate the rate and extent of current channel erosion and to track future bank erosion using erosion pin arrays. Results will identify and explain patters of bank erosion along Wilsons Cree and this information will be used to evaluate the chances for stream bank recovery in the future.

Physical and Geochemical Characteristics of Agricultural Soils from Southern Jamaica

Michael Jahnke
Geography, Geology, and Planning
Faculty Advisor: Dr. Robert Pavlowsky

Developing sustainable agricultural systems requires knowledge of soil properties and the use of this information to improve soil fertility and farming practices. In south-central Jamaica the climate is tropical to temperate, dependent on location relative to the mountain elevation. Farmers need to adapt to problems caused by increased drought frequency and limited water supplies over the past decades. This study determines the physical and chemical properties of three soil profiles collected from one farm. Core locations vary slightly due to landform and moisture conditions. Soil samples collected at 10-15 cm intervals are analyzed for pH, metals, texture, organic carbon, Munsell color, porosity, and water-holding capabilities. These results will be used to aid in fertility assessments and to help support climate change studies in the region.

Geochemical Properties of Burlington-keokuk Limestone Residuum, Greene County, MO

Alex Olive
Geography, Geology, and Planning
Faculty Advisor: Dr. Robert Pavlowsky

Residual soils overlying surficial bedrock will have unique geochemical characteristics depending on the age and composition of the parent material. The purpose of this study is to obtain the geochemical properties of residual soils overlying the Burlington-Keokuk Limestone in Greene County, Missouri. The Burlington-Keokuk is a marine sedimentary rock deposited during the Mississippian Period, and is composed of calcium-bearing carbonate minerals. The Burlington-Keokuk underlies the majority of the county and is known for karst topography with numerous sinkhole and caves found within the formation. A total of 53 samples were collected at 6 sites from 10-150 cm above exposed bedrock along road cuts. Samples were dried at 60°C, disaggregated by mortar and pestle, and sieved to <2mm. Geochemical properties were collected by X-Ray Fluorescence analyzer. Samples will also be analyzed for inorganic/organic carbon and grain-size characteristics. The results of this study will be included in database housing information on local soil characteristics that can be used for future projects.

Mining Chat Contributions to the Big River in St. Francois County, Missouri

Jennifer Witt
Ozarks Environmental and Water Resources Institute & Geology
Faculty Advisor: Dr. Robert Pavlowsky

Mining chat is composed of blue-gray dolomite fragments in the very fine-to medium-gravel size range. It was created as a waste product of gravity separation during lead ore milling in the Old Lead Belt in St. Francois County, Missouri. Erosion and slope failure released chat to the Big River until 2012 when remediation was completed. This study determines the relative contribution and spatial distribution of chat in present-day channel sediments along a 37 km segment of the Big River from Leadwood to Bonne-Terre, Missouri. Sediment samples were collected at 81 sites over 400 m intervals from channel bars. Each sample was sieved into three different size fractions (2-4 mm, 4-6 m, and 8-16 mm) and sorted according to lithology (chert/natural sediment, dolomite chat, and coal/slag). Mining chat percentage within the 4-6 mm and 2-4 mm bar sediment fraction averages 18%-24% from Leadwood to the Desloge pile, 36% and 50% from Desloge to Turkey Creek below Bonne-Terre, and 18% and 41% from Turkey Creek to Highway E bridge, respectively. Dolomite percentages in the 8-16 mm fraction were lower. Historical mining in Missouri has left sediment legacy in the Big River that will probably last for centuries.