Mapping fractures in 3D from airborne LiDAR: comparison with field mapping

We tested whether public high-resolution airborne LiDAR data could be suitable for structural geology applications by comparing fracture orientation measurements on Virtual Outcrop Models (VOMs) to field measurements from the same outcrops. We found that the fundamental requirement for taking full advantage of such data is good bedrock exposure, which is also dependent on lithology. Whenever this requirement is satisfied, VOM measurements are comparable to field measurements. VOMs can help considerably in both reducing the time it takes to collect measurements, and in expanding the area in which measurements can be collected without adding significantly to the time budget. They are also especially useful in remote regions and at high elevations, where access is more difficult and yet good exposures are more likely to be found, and they should always be used when planning field work. At present  the main limitations, apart from LiDAR coverage not yet existing in places, are due to the hardware and software capabilities needed to create and especially to analyze VOMs.