| Abstract: | In west-central Florida, sections of the Upper Floridan aquifer system range in character from confined to leaky to unconfined. The confining unit is the Hawthorn Formation, a clay-rich sequence. The presence or absence of the Hawthorn Formation affects the geochemical evolution of the ground water in the Upper Floridan aquifer system. Mass-balance and mass-transfer models suggest that, in unconfined areas, the geochemical reactions are dolomite dissolution, ion exchange (Mg for Na, K), sulfate reduction, calcite dissolution, and CO2 exchange. In the areas in which the Hawthorn Formation is leaky, the evolution of the ground water is accounted for by ion exchange, sulfate reduction, calcite dissolution, and CO2 exchange. In the confined areas, no ion exchange and only limited sulfate reduction occur, and the chemical character of the ground water is consistent with dolomite and gypsum dissolution, calcite precipitation, and CO2 ingassing. The Hawthorn Formation acts both as a physical barrier to the transport of CO2 and organic matter and as a source of ion-exchange sites, but the carbonate-mineral reactions are largely unaffected by the extent of confinement of the Upper Floridan aquifer. ?? 1994. |
| Genre: | Article |
| ProdID: | 70017988 |
| Citation Author: | Wicks, C. M.; Herman, J. S. |
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| Citation End Page: | 155 |
| Citation Issue: | 1-4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Hydrology |
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| Citation Number Of Pages: | 17 |
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| Citation Search Results Text: | The effect of a confining unit on the geochemical evolution of ground water in the Upper Floridan aquifer system; 1994; Article; Journal; Journal of Hydrology; Wicks, C. M.; Herman, J. S. |
| Citation Start Page: | 139 |
| Citation Volume: | 153 |
| Citation Year: | 1994 |
| Type: | citation/reference |
| Text: | The effect of a confining unit on the geochemical evolution of ground water in the Upper Floridan aquifer system; 1994; Article; Journal; Journal of Hydrology; Wicks, C. M.; Herman, J. S. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sat, 1 Jan 1994 00:00 -0600 |
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