Seasonal calcite precipitation dynamics were investigated at a calcareous fen (Vernon Marsh) in Mukwonago, Wisconsin. Calcareous fens are fed by groundwater in contact with dolomite, CaMg(CO3)2. As such, plant life in these fens has adapted to growing in the presence of high calcium and alkalinity. For each five-week sampling episode over the summer and fall, marble tiles were placed at a groundwater discharge area and at ten locations downstream. The tile mass gained or lost was used as an indicator of calcite precipitation or dissolution. Additionally, measurements of alkalinity, pH, CO2, dissolved O2, conductivity, and water temperature also were taken to understand the fen's surface water geochemical characteristics. Preliminary data suggests that in summer months there is calcite precipitation which corresponds with CO2 exolution and increases in pH as you move downstream from the discharge source. In colder temperatures we expect to measure calcite dissolution.

Calcite precipitation and geochemistry in a calcareous fen

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.