VIRTUAL FIELD WORK AT THE WHALEBACK ANTICLINE: MEASURING FOLD GEOMETRY IN A WEBGL-BASED GAME

Folds are spectacular geologic structures but measuring and representing fold geometry in 3D can be challenging for students, especially with regards to stereographic representations of folds. Bear Valley Strip Mine (Shamokin, PA) is a popular destination for structural-geology field trips for its well-exposed fold train; however, access to the site has evolving limitations. To extend the educational opportunities at the strip mine to a broader student group, we are designing a first-person-perspective game in which the user can explore the mine with classic field tools (geodetic compass, map, jetpack) to measure bedding attitude and create stereonet plots of poles to bedding. The game is still under development, but this summer, students at the University of Washington used the primary components of the game in an assigned remote field exercise as part of a virtual field course.

We are building the game in Unity3D, an agnostic gaming engine, with a Structure-from-Motion-derived polygonal model of the strip mine as the primary terrain. We published the game to WebGL, a platform supported by standard web browsers, to provide the greatest accessibility to our students remotely. After short presentations on fold geometry and a brief refresher on stereonets, the students received a link to the game and a related assignment. With the game’s tailored measurement and plotting tools, the students generated three deliverables: a map of the folds with bedding attitudes and fold axes on an orthophoto of the strip mine; a profile of the bedding surface interpolated across covered sections; and stereonets of poles to bedding and best-fit fold axes along three scanlines. The assignment also included tasks involving objective descriptions, the observations of meso-scale structures, and assessment of the quality of the strike-and-dip measurements. Ultimately we aim to produce a game with robust data-collection tools and limited narrative that will open a multitude of pedagogical opportunities for geology instructors.