GEOARCHAEOLOGICAL APPROACH OF ASSESSING THE LEGACY POLLUTION OF CIVIL WAR BATTLE FIELD: A CASE STUDY OF BATTLE OF THE CRATER OF VIRGINIA

The Battle of the Crater was a significant event between Union and Confederate forces during the American Civil War in Petersburg, Virginia. Desperate for progression, Union forces created a secret tunnel reaching Confederate picket lines in July of 1864. After completion the tunnel was filled with 8,000 lbs. of gunpowder and exploded, killing about 300 Confederate soldiers on impact. This explosion was followed by Union soldiers charging to the opposing force with the expectation of a weakened barrier but was instead met with a large crater and wall left from the explosion, giving confederate forces an uphill advantage and led to almost 5,300 casualties on both ends.

The purpose of this study is to analyze the geological and archaeological effects caused by the underground explosion during the Battle of the Crater. The intention of the present research is to indicate a disturbance produced by the explosion by examining and tracing the geochemical signatures of legacy pollution from soil samples collected from and surrounding the crater.

The soil was collected by inserting a 1-inch diameter probe into the ground with permission from the director of the Petersburg Battlefield Museum. Sections were bagged and labeled in accordance with soil color and texture for a total of 18 samples. Portions of the samples were then prepared for elemental analysis by X-ray Fluorescence (XRF) analyzer and Field Emission Scanning Electron Microscope (FE-SEM) at the Nanomaterials Core Characterization Facility of Virginia Commonwealth University.

XRF data gives evidence of a geochemical signature left in the soil from the explosion and battle. There is an obvious spike of lead (Pb) and arsenic (As) concentrations in samples retrieved from the crater (samples C1-C10 with C1 as top soil sample). The 38.6 ppm lead concentration in C8 may be attributed to the initial explosion that would have uprooted lower and upper soil in the creation of the crater. Samples C5 and C6 both have a lead concentration of approximately 25 ppm which could signify the battle succeeding the explosion where lead ammunitions were used by both the Union and Confederate soldiers. More analyses should be completed to better understand the elemental soil composition left by the Battle of the Crater.