USING GROUND PENETRATING RADAR FOR GEOARCHAEOLOGICAL INVESTIGATIONS IN WNY

Ground penetrating radar (GPR) is a geophysical tool with many applications including subsurface geology, engineering, environmental studies, and archaeology. GPR sends pulses of electromagnetic waves into the subsurface where they interact with differences in electrical properties to create a 2D view of the subsurface. Resulting radargrams reveal subsurface features such as stratigraphic layers, buried foundations, utility lines, lost burials, etc. Additionally, by collecting data in a precise grid pattern, a 3D data block can be created by combining the parallel 2D views and allowing interpolation by GPR processing software. The resulting 3D visualization usually allows better interpretation of subsurface features compared to individual 2D profiles.

In this project, GPR data were collected using a GSSI SIR-3000 system over a large area at Old Fort Niagara in Youngstown, NY, in order to map subsurface features associated with past buildings. Eight grids of data were collected and combined into one large 3D data block covering approximately 3,000 square meters within the fort walls. The data block was analyzed and compared to historic maps of fort buildings to aid interpretation. Comparison of depth slices of data to historic maps from different time periods over the last 300 years enabled a more complete interpretation of the area. Mapped features in this study include stone foundations of past buildings, previous topography associated with a seawall, and possible locations of trash pits and hearths. Data were collected over 4 days in the summer of 2014 and are being used to assist the Buffalo State Archaeological Field School in planning excavations for the summer of 2015.

GPR was also used at two local cemeteries to assist in ongoing restoration projects at the sites. Data were collected in a total of 13 grids at the two cemeteries to generate 3D views of the subsurface and to map lost burials. In conjunction with total station data collected by the Buffalo State Archaeological Field School, dozens of lost burials were located and will be commemorated with markers. Interpretations made while collecting data located several buried headstones that have now been re-earthed. At both cemeteries and at Old Fort Niagara, GPR proved to be an invaluable tool for collecting data in areas that required a non-invasive survey method.