VISUALIZING THE EVOLUTION OF FAULT SYSTEMS DURING PROGRESSIVE DEFORMATION

QuickTime movies produced from analog model experiments free students from trying to visualize a dynamic process using a static image and permit them to observe how fault systems behave and evolve during progressive deformation. A combination of a deformation apparatus based on a device described by McClay (1987), a digital video camera, and a Media 100 digital video editing system can produce a highly detailed, short duration movie of a complicated and lengthy experiment.

Individual frames from the movie provide a template on which students can identify the sequence of fault development, rotation of faults and sand layers, fault shape changes, and cessation of motion on some faults as they become inactive. Requiring students to document their observations, establish a chronological sequence of events, and explain in writing what happens during the experiment results in an increased awareness of the faulting process.

Students are asked to consider the following for their written description: Do structural elements maintain the same orientation during the experiment? Do any shape changes occur? Do all faults remain active throughout the experiment? Do all faults initiate with the same orientation? Do faults ever offset other faults? Do any features other than faults form? If time permits, it is especially instructive for students to compare fault evolution in experiments with different structural controls.

QuickTime movies, images, and an activity utilizing these resources are available at: http://serc.carleton.edu/NAGTWorkshops/structure04/activities/3861.html