Long Demonstrations, Set #1

Session #1 (Sunday 10:30) , repeated in Session #5 (Thursday 8:30)

---

L1A: Venus, Earth's Structural Sister: Investigations using radar imagery (Vicki Hansen, University of Minnesota, Duluth). Ever dream of an entire planet with ~100% structural exposure (no nasty sediments, biology, or obfuscating water)? Venus is the place! We'll use Magellan radar imagery (regular and synthetic stereo) to examine planet-scale structure- tectonic problems for classroom use. Concepts include remote data set interpretation, structure morphology and interaction, rheology, large-scale planet processes and more.

L1B: Physical Experiments Demonstrate the Relationship Between Strain, Stress, and Rheology (Basil Tikoff, University of Wisconsin). A major conceptual jump for many students in structural geology is making the connection between theoretical idealizations (stress, strain, rheology) and physical reality (rocks). Physical models are an excellent bridge in relating these two, because the boundary conditions and the material behavior are simplified. Further, the material deformation is directly observable, and a concept of progressive deformation is reinforced. This session will use an exercise that employing simple, hands-on physical models to provide an intuitive feeling for strain, stress, and rheology, and allows some quantification of these parameters.

L1C: Hypothesis Testing and Breakin' Rocks (Michelle Cooke, University of Massachusetts). In its coulomb criterion form, rock strength discussions can become bland and tedious. Analog devices can revive rock strength conversations by allowing students to witness real rocks break; furthermore, students can collect their own strength data to test self-developed hypotheses. This session will demonstrate a rock failure experiment and provide ideas for integrating rock strength hypothesis testing with Schmidt hammers, uniaxial compression rigs or rock core splitters into structural geology courses.

L1D: Using "An Introduction to Structural Methods" - An Interactive CD-ROM - In and Out of the Classroom (Tekla Harms, Amherst College). This session will explore innovative uses of this CD-ROM (available from Tasa Graphic Arts, Inc.) in support of teaching and learning in structural geology. Intended to supplement rather than replace conventional texts and lectures, this tool seeks to bring the best attributes of the medium to bear to enhance understanding in structural geology by supporting topics richly with color maps, 3D diagrams, and animations. Many of the resources on the CD are appropriate for classroom presentation, but the subjects covered are presented in an instructional format and include interactive exercises so that students can also use the CD for self-directed inquiry.

L1E: Composite session on fracture experiments with the following 6 short presentations:

• Fracturing Demonstration Using a Hydraulic Press (Jamie Harris, Millsaps College). This demonstration supplements investigation of the physical process of brittle deformation. A hydraulic press is used to fracture a core of the Yazoo Clay (Upper Eocene Jackson Group) of central Mississippi. The demonstration simulates a uniaxial compression test and allows students to measure shear plane orientations and determine the Coulomb coefficient for low-confining stress fracture experiments.
• Joint Development in Jello and Plaster (Zeshan Ismat, Franklin and Marshall College). No description available.
• Conjugate Fractures form in Clay (Paul Kelso, Lake Superior State University). A block of pottery clay deformed with a standard hydraulic rock trimmer produces beautiful conjugate fractures at approximately 30° to sigma 1. This activity is relevant to multiple discussions such as: 1) fracture orientation and principle stress directions, 2) conjugate fractures, and 3) Mohr-Coulomb failure. The demonstration can either generate initial discussion about the fracturing of materials or serve as a follow-up activity to drive home the point that the theory really does explain observations.
• Testing Anderson's Theory of Faulting—A Physical Experiment (Linda Reinen, Pomona College). A sandbox experiment demonstrating the formation of high angle normal faults. Helps students to visualize 3D stresses and enables them to predict fault type and attitude prior to the experiment. This experiment takes only a few minutes, so students see the results quickly.
• Cracking and Crumbling: Exploring Mechanisms of Dike Emplacement (Phillip Resor, Wesleyan University. The intrusion of dikes into the upper crust can be modeled as a pressurized crack in an elastic medium. In this exercise students analyze published geologic maps to explore the shape of basaltic dikes intruded into shales near Shiprock, New Mexico. Students are asked to assess how well the elastic model fits the mapped dike geometry and to hypothesize alternative intrusion mechanisms for areas where the elastic model appears inadequate.
• Demonstrating Normal Faults in Sand in a Shoe Box (Betsy Torrez, Sam Houston State University). Sandbox experiments have been used by structural geologists for decades to investigate the geometries and kinematic development of common classes of faults, as well as inversion structures. Sandbox models can be effective hands-on tools for introducing key concepts related to faulting in undergraduate structural geology classes. This session will provide step-by-step instructions on creating a sandbox model in a shoe box, a demonstration of normal faulting, and an overview of important concepts illustrated in the model.