Abstract:
We have developed a problem-solving lab exercise using real IODP data and graphic correlation to address planktonic community change at the Eocene-Oligocene boundary. This stratigraphic interval represents a time of dramatic global cooling, but the change is expressed in different ways and to different degrees at different locations in the world's oceans. The question the students are asked to address is whether observed changes in taxonomic composition across the Eocene-Oligocene boundary are global or local responses to changes in oceanic and atmospheric circulation. First, students were introduced to graphic correlation, a quantitative biostratigraphic technique that incorporates data from many local sections into a composite reference section. Second, students were taken to the core repository of the Integrated Ocean Drilling Program on the campus of Texas A&M University to examine the Eocene-Oligocene boundary in a series of cores from the Indian and Pacific Oceans. Some cores show virtually no lithological change at the boundary, whereas others show dramatic changes in rock type. Finally, students were asked to download biostratigraphic data from the IODP on-line Janus database from the same cores that they had measured and use them to create a composite global reference section. Using their own observations of the cores, the results of their graphic correlation of the real data, and additional information they were provided by IODP scientists during their field trip to the repository, students addressed the global versus local nature of biotic change at the Eocene-Oligocene boundary. Evaluations from students will assess the effectiveness of this exercise and reflect the value of integrating technology in geoscience curriculum.