Utilizing Ground Penetrating Radar (GPR) to Detect Paleontological Features in Ash Beds

Ground penetrating radar (GPR) is a non-invasive method that has been successfully used in archaeological and forensic research. However, there has been little research on the application of GPR for similar field of study: paleontology. Previous studies have concluded that GPR can be a useful method in identifying bone assemblages in sand matrix soils; but there is no research on the detection capabilities of GPR bones encased in volcanic ash deposits. To address this, we tested high frequency (500 MHz and 1000 MHz frequency) GPR to detect the presence of Miocene age bone assemblages in fine Konservat Lagerstatte ash layer deposits at Ashfall Fossil Bed State Historical Park in Royal Nebraska. The goal of this research was to identify regions of potential bone bed assemblages in the unexcavated sections of the site areas for future excavation. Overall, the GPR frequency used within this survey was successful at detecting the interface between ash and sandstone layers. Areas of interest potentially containing animal skeletons are interpreted as the loss of reflector continuity and decrease in amplitude strength in the otherwise continuous and low-loss ash deposits. The ash/sandstone interface was identified by a characteristic loss of signal strength in the underlying, higher signal attenuation sandstone. Overall, the GPR was successful in imaging the subsurface paleostratigraphy as well identifying regions of interest that may contain the remains of prehistoric animal bone assemblages.