Booth, Colin J.
M.S. (Master of Science)
Department of Geology
Hydrogeology--Illinois--De Kalb County||Hydrogeology--Illinois--Kane County||Dolomite--Illinois--Kane County||Dolomite--Illinois--De Kalb County
The Galena-Platteville Dolomite is present at the bedrock surface in north-central Illinois, where it is part of the Upper Bedrock Aquigroup (UBA). It is overlain by the Silurian Dolomite and Maquoketa Confining Unit in northeastern Illinois, where it is part of the Midwest Bedrock Aquigroup (MBA). This study evaluates the hydrogeology of the Galena-Platteville in an area where it makes the transition from the UBA to the MBA. Packer test and potentiometric data were collected at 33 test holes drilled to evaluate the geologic feasibility of siting the proposed Superconducting Super Collider (SSC) in a tunnel within the Galena-Platteville in DeKalb and Kane Counties, Illinois. Additional potentiometric data were obtained from domestic water wells in DeKalb County. These packer test and potentiometric data, along with examination of the recovered core, were used to: determine the nature and occurrence of groundwater in the Galena-Platteville; determine groundwater flow directions and rates through the Galena-Platteville; evaluate previously published hypotheses regarding the Galena- Platteville; and evaluate the role of the Galena-Platteville within the hydrostratigraphic setting of northern Illinois. Study results indicate that permeability and porosity within the Galena-Platteville is related to the development of a sucrosic texture in the dolomite. This porous texture appears to contribute significantly to the groundwater storage capacity of the Galena- Platteville by increasing porosity, while imparting a moderate permeability in the range of 10⁻⁶ to 10⁻⁵ cm/s. Fracture permeability is locally in the range of 10⁻⁴ to 10⁻³ cm/s. The Galena-Platteville reflects a denser texture where it is a limestone, having a hydraulic conductivity of less than 10⁻⁶ cm/s. Groundwater flow through the Galena-Platteville, where it is part of the UBA, follows the topographic trend of the bedrock surface. Groundwater flow converges toward the Troy and Rock Bedrock Valleys, where it discharges to the underlying Ancell Aquifer. Thick sections of the Galena-Platteville serve as a confining unit for the MBA where the Maquoketa Confining Unit is absent. Heavy pumping from underlying sandstone aquifers influences the Galena-Platteville in northeastern Illinois. In Kane County the Maquoketa Confining Unit limits recharge resulting in partial dewatering of the Galena-Platteville.
Schumacher, David A., "The hydrogeology of the Galena-Platteville dolomite in DeKalb and Kane counties, northeastern Illinois" (1990). Graduate Research Theses & Dissertations. 5836.
ix, 173 pages
Northern Illinois University
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