From Bureau of Economic Geology, The University of Texas at Austin (www.beg.utexas.edu).
For more information, please contact the author.

AAPG Annual Convention, Calgary, Alberta, Canada, June 19–22, 2005

Taking Turbidite Outcrops to the Next Level: 3-D Visualization, Characterization, and Interpretation of Analogs Using LIDAR Technology

David Jennette, Florence Bonnaffé, David Pyles, Renaud Bouroullec, and Mark Tomasso

Lidar (light detection and ranging) is part of an emerging digital toolkit that improves the rapid, quantitative characterization of outcrop geology. Recent advances in acquisition, processing, handling, visualization, and interpretation provide improved data capture and analysis methods when compared with traditional photograph-based or hand-held global positioning system (GPS) methods. Outcrop faces are readily placed into navigable 3-D volumes that can be examined immediately in the field and later interpreted on a workstation or computer. A virtual world is at hand as digital photos are routinely draped onto digital terrain models. Simply put, we can ask questions and seek answers from the outcrop at a pace and accuracy that were not previously possible.

Ongoing examinations of well-studied turbidite outcrops such as the Capistrano of San Clemente, California, the Brushy Canyon of West Texas, the Ross Sandstone of Ireland, and the Tabernas Basin of Spain are providing new perspectives of classic analog exposures. We can conduct 3-D interrogation of the outcrop by positioning ourselves in an infinite number of “virtual” vantage points and observe relationships not visible or apparent while on foot. Time-significant horizons, lithofacies, and faults are interpreted directly onto the laser-generated point clouds, similar to the interpretation of 3-D seismic data. Horizons can be projected from the outcrop onto arbitrary planes that are oriented normal to paleocurrents, giving true cross-sectional geometries instead of apparent relationships. The value of this work is realized with the integration of these data into 3-D models using the Gocad integration environment.