THE STRUCTURAL GEOLOGY MAPPING CHALLENGE: AN EVOLVING TOOL FOR ONLINE GEOSCIENCE EDUCATION

The Structural Geology Mapping Challenge is a highly interactive game-like activity that leverages the Google Earth application program interface (API) to present students with opportunities to develop skills in recognizing and mapping geological structures in the field. Students fly to an instructor-generated location in Google Earth where they can translate, rotate, and scale a semi-transparent plane in order to fit it to the map traces of planar structures. The fit of the plane to a flat-iron is particularly striking. It makes the three-dimensionality of the structure ‘pop-out.’ The planes orientation is linked to an interactive great circle on a stereographic projection that floats over the Google Earth window. Students can drag the pole to the great circle in order to see the effects o the ground.

The challenge for students in our current version is to estimate bedding at several points around a fold in Big Horn Basin, WY. Student estimates of strike and dip are auto-scored by the computer, which calculates the cross-product of the poles to student and instructor bedding planes. Students are awarded medallions based on closeness of these estimates. After fitting bedding planes, students fit a great circle through the poles to bedding in order to determine the fold axis and they fit a plane to hinge points of successive beds to pin down the axial plane. Finally, students can fit bézier curves to periclinal fold cross sections and long sections. This is important to teach the lesson that inclined folds do not plunge uniformly forever. Guerrilla testing is scheduled for Spring 2015 and initial results will be reported.