Prairie Research Institute University of Illinois at Urbana-Champaign
Assorted Illinois State Geological Survey publications that focus on various topics in Champaign County and surrounding areas.
David L. Reinertsen, Dwain J. Berggren, John P. Kempton, and Paul DuMontelle, 1977
Special Report 6 Geologic Cross Sections of Quaternary Deposits Across the Manlove Gas Storage Field Area, Champaign County, Illinois
Andrew J. Stumpf. 2018. 7 pp., including 2 fold-out cross sections
Special Report 6 was developed by the Illinois State Geological Survey to assist the Prairie Research Institute’s Natural Gas Working Group (NGWG), the Illinois Environmental Protection Agency (IEPA), and other stakeholder groups in understanding the local geologic deposits in northwestern Champaign County. The cross sections depict the geologic materials encountered between the land surface and the buried bedrock surface. These are the first detailed representations of Quaternary deposits that overlie the Manlove gas storage field.
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INHS B35-02: The Fishes of Champaign County, Illinois, During a Century of Alterations of a Prairie Ecosystem
$10.00 Close out sale $1.00 Authors: Larimore, R.W. and P.B. Bayley; T.E. Rice and C. Warwick, eds. 1996; 130 pages.
Geologic Cross Sections Across the Mahomet Bedrock Valley, Champaign, Ford, McLean, Piatt, and Vermilion Counties was developed in the process of building a three-dimensional geologic model of the Mahomet aquifer. These detailed illustrations provide a window into the subsurface of this part of east-central Illinois that was not possible before. The cross sections depict the geologic materials encountered between the land surface and the bedrock along specific lines, or transects, across the Mahomet Bedrock Valley. The sequences shown of clayey sediment, interpreted as till and glacial lake sediment, and glacial sand and gravel capture the complex history of deposition and erosion of at least three main episodes of glaciation during the Quaternary Period. This map will be an important resource for people in the region who study or manage the underground water supplies, especially those involved in modeling groundwater flow, estimating water supplies, or evaluating water quality.
Special Report 7 Water Quality in the Mahomet Aquifer: Chemical Indicators of Brine Migration and Mixing
Samuel V. Panno and Walton R. Kelly, 2020 Print on Demand
Bedrock formations within the Illinois Basin contain concentrated brines with unique chemical fingerprints that can be used to identify the geologic ages of formations from which the brines originate. Using chloride/bromide mass ratios, it is possible to identify the source of errant brines that may have entered wells screened within an aquifer. Recent questions about the origin of methane gas entering wells screened within the Mahomet aquifer may be addressed if the gas is associated with even a minute amount of a telltale brine. Here we present a methodology for identifying the source of brines seeping into the Mahomet aquifers. This is possible because chloride concentrations and chloride/bromide ratios within the eastern half of the Mahomet aquifer are extremely low (about 1 mg/L and 100, respectively). For comparison, today’s rainwater and snowmelt typically contain less than 0.2 mg/L of chloride, with chloride/bromide mass ratios of about 100. Basin brines can have chloride concentrations of more than 100,000 mg/L and chloride/bromide mass ratios ranging from 200 to 800. Consequently, the seepage of brine into the Mahomet aquifer should be traceable to its formation of origin by using chloride/bromide ratios.
Steven E. Brown, Jason F. Thomason, and Kisa E. Mwakanyamale. 2018. 25 pp.
The Future of Science of the Mahomet Aquifer aims to show that the science of the Mahomet aquifer is a serious issue of public concern. To conserve this valuable water resource for present and future generations, we must accelerate scientific understanding of the aquifer by developing far-sighted strategies and implementing technologies that would reveal aquifer details broadly. Part 1 of this circular makes the argument that we still lack an adequate understanding of the complex geology and hydrogeology of the aquifer. Part 2 describes the results of a workshop hosted by the Prairie Research Institute on June 28, 2017, which brought together researchers and stakeholders to discuss, list, and consider the most relevant topics regarding groundwater in the aquifer. Part 3 lays out a bold path forward to gain a comprehensive understanding of the complex geology and hydrogeology of the aquifer: large-scale scientific mapping of the subsurface via helicopter-borne time domain electromagnetic geophysical surveying.
By S.V. Panno, K.C. Hackley, E. Mehnert, D.R. Larson, D. Canavan, and T.C. Young. 2005. 51 pp.
This report summarizes the results of research undertaken by ISGS hydrogeologists and isotope geochemists on behalf of Illinois-American Water Company. Over a period of three decades, the company had observed progressive decreases in the specific capacities of most of its high-capacity wells screened in the Mahomet aquifer at Champaign, Illinois. Based on the study results, encrustations on the well screens were likely to have been caused by iron-depositing bacteria producing biofilms on the well screens that trapped transported mineral fragments, clay minerals, and newly precipitated calcite crystals. This process was responsible for the decrease in specific capacity. The scientists suggested that inspecting well screens of other problem production wells in the aquifer and collecting and analyzing samples of any encrustation should yield valuable information about the nature of the encrustation that could help researchers and companies identify appropriate remediation techniques.
Surficial Geology of Rantoul Quadrangle
Stumpf, A.J., 2014, 1:24,000. Description: Three 36" x 30 " map sheets; sheet 1 contains map, 2 inset maps, and legends; sheet 2 includes 3 cross sections and legend; sheet 3 contains descriptive text with 6 figures.
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