Geophysical Investigation of River Dredge Material along the Savannah River, Jasper Co, SC Grant uri icon

abstract

  • Our goal is to determine the depth and spatial extent of river dredge spoils at a site adjacent to the Savannah River, Jasper Co., South Carolina. We will use electrical resistivity and ground penetrating radar surveys to estimate the depth and extent of the spoil materials. The geological characterization will ultimately help determine the depth at which archaeological surveys will be conducted, at depths directly below the spoil materials. Keith Seramur has been collaborating with the. Georgia Department of Transportation on projects characterizing site geoarchaeology. In this case, large amounts of river dredge material have prevented access to sites where potential archaeological artifacts are located. In order to determine the potential location of artifacts the thickness of river dredge spoil, where artifacts are unlikely, must be established. We will use electrical resistivity and ground penetrating radar surveys to estimate the depth and extent of the spoil materials. Three days of geophysical surveying will be conducted during the fall or winter months. Scheduling will be arranged with Keith Seramur. East Carolina University will provide at least one faculty member (Mike O'Driscoll or Dave Mallinson) and one graduate student to help with geophysical surveys. Depending on site accessibility the surveys will be conducted with an all-terrain vehicle or manually. We will estimate thicknesses of the dredged material from the land surface and provide estimates of depth at surveyed points. Both electrical resistivity and ground penetrating radar survey depth vary depending on the nature of the subsurface sediment, if the material is highly clay-rich and conducts electricity well, the depths of surveys may be limited. Typically in Coastal Plain settings electrical resistivity surveys can penetrate to 10m. We will conduct at least 3 (electrical resistivity and/or gpr) transects a day for 3 days and then interpret these data. Following interpretation we will return to the site with a geoprobe sediment sampling rig and drill confirmatory cores at select sites. The goal is to drill through river dredge materials to the native materials underneath. Geoprobing will confirm the depth of river dredge spoils and will collect continuous cores in the native materials that will be analyzed for microartifacts by Keith Seramur. After the initial geophysical surveys we will spend two days geoprobing. Locations of potential cores will depend on site accessibility and the interpretations of geophysical data. Based on the estimated thickness of river dredge materials (~8 m), we will aim to collect at least 4 cores/day with a focus on collecting sections from 8-12m depth. Based on two days of coring we aim to collect at least 8 cores, with a total core length of at least 10m. This study will help determine how accurate geophysical techniques are at estimating anthropogenic alterations to river floodplain systems. The maps generated will show how much river dredge material has changed the floodplain and how thick the deposits are. After determining how thick dredge spoils are, the samples collected underneath the spoils will show if the buried sites were potentially rich sites for archaeological artifacts.

date/time interval

  • August 2008 - July 2009