1. Department of Geological and Environmental Sciences and the Mallinson Institute for Science Education, Western Michigan University, Kalamazoo, Michigan 49008;
2. Department of Physics, Astronomy, and Geosciences, Towson University, Towson, Maryland 21252;
3. The Mallinson Institute for Science Education, Western Michigan University, Kalamazoo, Michigan 49008;
4. Department of Geological and Environmental Sciences, Western Michigan University, Kalamazoo, Michigan 49008