ELECTROMAGNETIC SURVEY TO LOCATE GRAVES AND OTHER INTERESTING ARCHAEOLOGICAL FEATURES

Near-surface geophysical found their place in archeology studies over the past several decades. During this investigation, exploratory electromagnetic mapping was done at two archeology sites in an attempt to locate graves with reasonable results. The area of Happy Valley, Oswego County, NY was settled and farmed until government reforestation program was carried out in the 1930’s, thereby requiring the inhabitants to be relocated. One of the sites in Happy Valley, includes small grave sites, possibly family plots, with potentially numerous unmarked graves. Near the village of Canton, NY in St. Lawrence County, the 19^th century poorhouse included a burial ground with ore than 500 graves. The poorhouse was destroyed in the 1970’s and much of the grave yard was forgotten. A renewed interest to preserve the site included possibly locating hundreds of unmarked graves of people that lived at the poorhouse. Preserving the historical value of both of these sites has included archeology investigations, and electromagnetic surveys were completed to aid in this endeavor. Both investigations deployed a GSSI EM 400 Profiler with 5, 10 and 15 kHz signals run simultaneously. Data was collected by walking survey at a rate of two readings per second and tracked with GPS with the transmitter and receiver oriented horizontal. Conductivity maps were produced for each site revealing a variety of anomalies with conductivity range of 10’s of mS/m. At both sites, rows of higher conductivity anomalies occur within an overall back ground low conductivity. These rows of anomalies are interpreted as individual graves at Happy Valley, however, at the Canton site larger anomalies may represent multiple trench graves. These exploratory maps were later used for GPR targeting, and geospatial location of possible graves.