T234 Urban and Suburban Lakes: Paleorecords of Human Impacts and Opportunities for Geoscience Education

Wednesday, 12 October 2011
8:00 AM - 12:00 PM
Room M100DE

STUDENT ASSIGNMENTS FOR WORKING WITH LAKE SEDIMENT CORES

Paper number: T234-12
Program: Technical Sessions
Time: 10:45 AM – 11:00 AM

Authors

Abstract

Lake Sediment Coring has been used as a teaching and learning tool with high school and upper-level undergraduate students. For students involved with the coring process (which we have undertaken during the winter), the students experience the reality of ‘extreme’ field conditions, the need to use and apply simple but essential math, simple engineering, geographic location skills, field note-taking skills, and field sample organization, as well as the thrill of retrieving sediment cores. At the Middle and High School level students focus on lab work that involves visual description, and evaluation of the detrital components, especially the diatoms. Middle- and High-School student assignments include summarizing their diatom data in a blog post (http://andrill-alcove.blogspot.com/).

At the undergraduate level a variety of assignments are tied to the coring. These include initial selection of sample sites in the context of the question being posed; this involves use of the Minnesota DNR ‘Lakefinder’ website (http://www.dnr.state.mn.us/lakefind/index.html), and review of latitude and Longitude (and conversion to/from decimal degrees) and topographic map reading. Preparatory work also includes evaluation of sediment data from nearby water wells, which requires use of the MN County Well Index (http://www.health.state.mn.us/divs/eh/cwi/index.html), construction of topographic profiles, and plotting and correlation of sedimentary units. Use of available surficial geology maps is also integrated into preparation for coring. The preparatory work, which also includes basic reading on limnology, allows students to make some reasoned predictions about the cores that will be extracted. Follow-up Lab work involves a trip to the Core Lab at the Limnological Research Center (http://lrc.geo.umn.edu/laccore/) to split and process the core, which is followed up by visual description and logging, grain-size analysis of selected intervals, and smear slide making and evaluation. Each student takes responsibility for one core or portion thereof, and each student has responsibility for producing a Lake Core report in which they integrate and interpret all the data, to tell the sedimentary history for the lake, and if possible, answer the research question posed.