Pond Sediment: Unlocking Puzzles of the Past
These activities were inspired by a research project using historical plant data to understand the impacts of industrialization in the 18th and 19th centuries on pond plant communities.
Historical plant data is gathered through the analysis of plugs of sediment ("cores") collected from the bottom of ponds. Sediment layers form on pond bottoms as soil washed into ponds settles through the water. Plant "macrofossils" (i.e., seeds and leaves) that have also sunk to the bottom are incorporated into the sediment and preserved. Macrofossils allow researchers to identify which species were present in Miller Woods ponds as far back as 3000 years ago! Since sediment cores are youngest at the top and oldest at the bottom, researchers can use macrofossils' locations to estimate their relative ages. Detailed element-isotope dating techniques can also be used to figure out the exact age of any particular sediment layer.
Some of these activities are focused on understanding how researchers use sediment sampling to gather historical data. Others are focused on the data itself, namely the changes in plant species that occurred after European settlers arrived approximately 150 years ago. Since that time, railroad development and the building of steel mills disturbed the Miller Woods ponds, leading to dramatic changes in plant community composition.
Activities are based on hands-on and interactive web experiences with data collected from two sediment cores in 2010.
Teacher Resources
Activities
Interactive core: Website