Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN><SPAN>The general model of Illinois ground-water hydrology depicts water infiltrating from the surface along the flanks of the basin and moving downdip, basinward over time (Selkregg and others, 1957; Mandle and Kontis, 1992; Young, 1992a, b). Several authors indicated that formation waters in the St. Peter Sandstone in the southern Illinois, western Kentucky area are highly mineralized (Meents and others, 1952; Hoholick, 1980; Cartwright and others, 1981), which indicates that the formation waters have resided in the formation for extended periods. On the basis of flow paths depicting ground-water flow in the St. Peter Sandstone to the central Illinois Basin that are typically more than 200 mi, and St. Peter Sandstone formation waters that are highly mineralized, we infer that fluid residence times are long, more than 10,000 yr. for southern Illinois and western Kentucky.</SPAN></SPAN></P><P><SPAN /></P></DIV></DIV></DIV>
Copyright Text: Cartwright, K., Gilkeson, R. H., Griffin, R. A., Johnson, T. M., Lindorff, D. E., and DuMontelle, P. B., 1981, Considerations in hazardous waste disposal in Illinois: Illinois Geological Survey, Geological Note GN 94, 20 p.
Collinson, C., Sargent, M. L., and Jennings, J. R., 1988, Chapter 14: Illinois Basin region, in Sloss, L. L., ed., The Geology of North America, v. D-2, Sedimentary Cover—North American Craton: U.S.: Decade of North American Geology: Geological Society of America, p. 383–426.
Hoholick, D. J., 1980, Porosity, grain fabric, water chemistry, cement, and depth of the St. Peter Sandstone in the Illinois Basin: University of Cincinnati, Master's thesis, 72 p.
Mandle, R. J., and Kontis, A. L., 1992, Simulation of regional ground-water flow in the Cambrian-Ordovician aquifer system in the northern Midwest, United States: U.S. Geological Survey, Professional Paper 1405-C.
Meents, W. F., Bell, A. H., Rees, O. W., and Tilbury, W. G., 1952, Illinois oil-field brines, their geologic occurrence and chemical composition: Illinois Geological Survey, Illinois Petroleum No. 66, 38 p.
Selkregg, L. F., Pryor, W. A., and Kempton, J. P., 1957, Groundwater geology in south-central Illinois—a preliminary geologic report: Illinois Geologic Survey, Circular 225, 30 p.
Young, H. L., 1992a, Summary of ground water hydrology of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: U.S. Geological Survey, Professional Paper 1405-A, 55 p.
___________ 1992b, Hydrogeology of the Cambrian-Ordovician aquifer system in the northern Midwest, United States: U.S. Geological Survey, Professional Paper 1405-B, 99 p.