USING ANALOG MODELING TO MEASURE STUDENT COMPREHENSION

The MAT 5315 course for in-service teachers working on a Master's degree at the University of Texas at El Paso (UTEP) is the 5th class in a 6 course series designed to increase geoscience content knowledge. As such, it is intended to build on a solid knowledge base from earlier classes and, with that assumption, the students were given a series of questions about the nature of the Franklin Mountains in El Paso. Although they had an earlier summer field course that covered the Franklin Mountains in great detail, they did not show much understanding of the major structural elements, lithologies, or how the mountains had formed. After discussing several mechanisms and critical observations, the students were given a demonstration of how sand might be used to model the mountain formation and simulate some of the observations. They were then given some colored sand and a variety of tools and boxes to try to recreate some of their ideas about how the mountains had formed. The results were very innovative and included:

1. A simple horizontal compression of flat sand layers to form folds 2. The down-dropping of one side of layered sand to simulate a monocline with a hidden normal fault 3. The inflation of a plastic bag beneath the layered sand to produce the effects of magma intrusion.

The first model, horizontal compression of the sand, was similar to the initial demonstration but the other two models were clearly drawn from what the students had learned previously about the history of the mountains. The mountains do include active normal faults and intrusive rocks but the students had completely forgotten the steeply dipping sedimentary rocks (clearly visible from any part of the city) that make up most of the mountain range. I assume the reason for that is that their only field class thus far had emphasized the igneous and metamorphic rocks that were the professor's particular interest. The students' exposure to sedimentary rocks, stratigraphy, and basic structural geology was limited to classroom lectures because those courses had to be taught at night to accommodate the in-service teachers' schedule. It is clear that the one field class had been far more educational than all of the lecture courses the teachers had taken. The final class in the sequence is a field class that focuses on the sedimentary history and should help in the students' understanding.