PRELIMINARY LOSS-ON-IGNITION DATA FROM CRYSTAL LAKE, OHIO

Crystal Lake located in Medway, Ohio (39°N 53’, 84°W 01’), is an 11 meter deep kettle lake, formed during the Wisconsinan glacial event, close to the glacial ice boundary. Lake sediment cores extending from 1130 to 2000 cm below the lake surface were collected in 2008. Loss of ignition (LOI) is a method used to estimate the amount of organic matter and carbonate in the sediment. The results from an LOI analysis, of the upper levels of the core indicate a high frequency variation in the percentage of organic material in the sediment (1200-1550cm) of 4 to 18% with an average of five to six fluctuations per meter. Previous studies of gastropod and diatom species indicate lake level change; perhaps these lake level changes affected the percentage of organic material. The current investigation includes: 1) LOI analysis of the remaining sediment (1650-2000cm), to determine if the variations continue or change in older sediments 2) radiocarbon dating of a wood fragment found at 1302cm 3) collaboration with researchers who are trying to understand the modern trophic status and groundwater system of the lake. Continued research at this site will enrich the overall understanding of the sedimentary history of the lake, while also shedding light on the paleoclimate of southwestern Ohio during the last glaciation.