Extending Virtual Outcrop Geology into the Subsurface – Combining Terrestrial Laser Scanning and Ground Penetrating Radar at the Bridge of Ross, Co. Clare
Modern field methods of digital data acquisition can record surface geology in unprecedented detail, and allow spatially precise, photo-realistic virtual copies of the outcrop to be constructed. Terrestrial laser scanning (LIDAR) and differential GPS are key technologies. 3D visualisation of the virtual outcrop (using standard desktop computers or high-end immersive systems) helps to increase overall understanding of the sedimentary architecture and structural style of the outcrop. Furthermore, virtual outcrop data can be analysed in detail using picking techniques that are broadly analogous to interpretation of seismic data. This allows high resolution geological measurements to be derived directly from the virtual dataset, and when combined with traditional field observations, has given major new insights into of a wide range of quantitative sedimentary and structural attributes.
A disadvantage in using terrestrial laser scanning to build virtual outcrops is that LIDAR data is essentially non-penetrative. While imaging of the topographic surface is highly detailed, sub-surface geology can only be interpreted by interpolating into the outcrop. One strategy to overcome this limitation is to use Ground Penetrating Radar (GPR) to image the shallow sub-surface. We illustrate this combined approach with GPR and LIDAR data from outcrops at the Bridge of Ross, Co. Clare.