The geochemistry of dissolved inorganic carbon in a surficial groundwater aquifer in North Inlet, South Carolina, and the carbon fluxes to the coastal ocean |
| |
| Authors: | Wei-Jun Cai Yongchen Wang WS Moore |
| |
| Institution: | 1 Department of Marine Sciences, The University of Georgia, Athens, GA 30602, USA
2 Department of Geological Sciences, University of South Carolina, Columbia, SC 29208, USA |
| |
| Abstract: | We report measurements of pH, total dissolved inorganic carbon (DIC), total or titration alkalinity (TAlk), Ca2+, Mg2+, sulfate, and sulfide data at the seawater-freshwater interface in a shallow groundwater aquifer in North Inlet, South Carolina. These measurements and a diagenetic modeling analysis indicate that the groundwaters at North Inlet are mixtures of seawater and freshwater end-members and are seriously modified by carbon dioxide inputs from organic carbon degradation via SO42− reduction across the entire salinity range and fermentation and CaCO3 dissolution in the low-salinity region. DIC and TAlk are several times higher than the theoretical dilution line, whereas Ca2+ is slightly higher and SO42− is somewhat lower than the dilution line. Partial pressure of CO2 in the groundwater is extremely high (0.05 to 0.12 atm). These deviations are consistent with theoretical predictions from known diagenetic reactions. Estimated groundwater DIC fluxes to the South Atlantic Bight from either the surficial aquifer (via salt marshes) or the Upper Floridan Aquifer (direct input) are significant when compared to riverine flux in this area. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
