| Abstract: | Contamination of groundwater from point and nonpoint sources (such as landfills, feedlots, agricultural chemicals applied to fields, and septic systems) is a recognized problem in the karst area of southeastern Minnesota. The US Geological Survey, in cooperation with the Minnesota Department of Natural Resources and the Legislative Commission on Minnesota Resources, Began a study in October 1987 to improve the understanding of local groundwater flow through karst terrain in southeastern Minnesota. The objectives of the study are to: (1) describe the orientations of systematic rock fractures and solution channels of the Prairie du Chien Group of Ordovician-age carbonate rocks in southeastern Minnesota, and, if possible, to define the principal and minor axes of these orientations; and (2) evaluate the effect of fractures and solution channels in the Prairie du Chien Group on the local flow of groundwater. Groundwater in the Upper Carbonate aquifer regionally flows toward the periphery of the aquifer and locally flows into streams and bedrock valleys. The hydraulic gradient in this aquifer generally is greatest near areas of groundwater seepage to streams. Regional groundwater flow in the Prairie du Chien-Jordan aquifer generally is to the south and east in much of Fillmore and Houston Counties and in the southern parts of Olmsted and Winona Counties. Groundwater seepage to selected streams was evaluated by current-meter measurements of downstream gains or losses of streamflow and by an experimental approach based on radon activity in streams. The activity of radon in groundwater ranges from two to four orders of magnitude greater than the activity in surface water; therefore, groundwater seepage to streams generally increases the in-stream radon activity. (Lantz-PTT) |
| Genre: | USGS Numbered Series |
| ProdID: | 20713 |
| Citation Author: | Ruhl, J. F. |
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| Citation Language: | ENGLISH |
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| Citation Phsyical Description: | 2 p. :ill. ;28 cm. |
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| Citation Publisher: | U.S. Geological Survey, Dept. of the Interior, |
| Citation Series: | Open-File Report |
| Citation Series Code: | OFR |
| Citation Series Number: | 89-253 |
| Citation Search Results Text: | Flow of ground water through fractured carbonate rocks in the Prairie du Chien-Jordan Aquifer, southeastern Minnesota; 1989; OFR; 89-253; Ruhl, J. F. |
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| Citation Year: | 1989 |
| Type: | citation/reference |
| Text: | Flow of ground water through fractured carbonate rocks in the Prairie du Chien-Jordan Aquifer, southeastern Minnesota; 1989; OFR; 89-253; Ruhl, J. F. |
| URL (THUMBNAIL): | http://pubs.usgs.gov/of/1989/0253/report-thumb.jpg |
| URL (DOCUMENT): | http://pubs.usgs.gov/of/1989/0253/report.pdf |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
| Publisher: | U.S. Geological Survey, Dept. of the Interior, |
