CREATING INTERACTIVE 3-D MODELS FROM GEOLOGIC MAPS AND CROSS SECTIONS USING GOOGLE SketchUp

The power of geologic maps and cross sections to portray the structure of a region is dramatically enhanced by software that can create interactive 3-D models, which can be rotated, panned, and zoomed by the user. I developed a methodology for creating virtual block diagrams from digital maps and cross-sections primarily using Google SketchUp. It is also essential to have an image-processing program, such as Photoshop, for cropping maps and cross-sections, and GIS software, such as Global Mapper, for preparing digital elevation models (DEM) for SketchUp.

The most effective 3-D models show how the maps and cross-sections connect at the topographic surface. The map can be segmented to give users the ability to ‘turn off’ individual portions of the surface to reveal cross-sections below. Such models help students and non-specialists visualize geologic structures, and provide experienced geologists with a valuable tool for assessing the validity of geologic interpretations.

Once a geologic map is draped on the DEM, SketchUp can aid in the creation of new geologic cross sections using traditional down-plunge and structure contour approaches adapted for a 3-D environment. This approach makes it possible to leverage the geologic information contained in geologic maps from regions with significant topographic relief. It also helps students effectively visualize the process of cross-section construction.