ANALYSIS OF THE RECLAMATION OF THE SUGAR RIDGE STRIP MINE REGION FROM LAKE SEDIMENTS

Ashby Lake and Arm Pit are two small reclaimed aquatic systems now located in the Sugar Ridge Fish and Wildlife Area in Winslow, Indiana. The region was formerly part of a coal strip mine, leased by the Amax Coal Company in 1964. The region was eventually donated to the Division of Fish and Wildlife in 1980 and has since been reclaimed and is now a wildlife area used primarily for fishing and hunting. In 2014, we collected two short (>1 m) sediment cores from the center of these two lake systems to explore the potential impact of acidic drainage on this system, and to assess the effectiveness of the reclamation process on water quality over the past several decades. Both cores were sampled at a 0.5-cm sample resolution to analyze changes in fossil diatom assemblages, major/minor element concentrations, and detailed phosphorus geochemistry. Diatoms are particularly sensitive biological indicators of acidity in aquatic systems and are commonly used to evaluate potential changes in water quality over time. Changes in the elemental concentrations will be evaluated by hand-held XRF and ICP-OES to determine heavy metal loads resulting from past mining activities and ongoing acidic drainage. A sequential extraction technique will be employed to elucidate sedimentary phosphorus associations to assess how the nutrient status of the lake has changed over time. Together these geochemical proxies will be used to explore landscape/watershed/lake interactions. Combining the geochemical and fossil diatom assemblage results will allow us to reconstruct the temporal variability in biogeochemical cycling of nutrients and metals within this aquatic system.