SUPPORTING ARCHAEOLOGICAL INVESTIGATIONS WITH NEAR SURFACE GEOPHYSICS AT THE HENRY WHITFIELD HOUSE IN GUILFORD, CONNECTICUT

Built in 1639 by the first minister and the leader of the founders of Guilford, the Henry Whitfield House in Guilford, Connecticut is the oldest stone house in the New England region of the United States. Designated a state historic museum in the late 1800s, archaeologists have been drawn to the site since the mid-1900s in search of archaeological history not only of the first settlers, but also of the Menuncatuck band of Quinnipiac from whom the land was bought by the settlers. Through the decades however, only a small area of the property where the house stands today has been explored and excavated. To support the on-going archaeological research at the site, we investigated the utility of non-invasive Ground Penetrating Radar as a tool to identify areas most promising for future excavations. The data were collected using 250MHz and 500MHz GPR transmitters in the known glacial till terrain of the site. GPR transects spaced at 25 and 50cm intervals and 1cm trace spacing covering a 20m by 3.5m experimental survey area running parallel to one of the exterior walls of the house was used for the study. Data revealed that maximum depth penetration of GPR in the geologic substrate is limited to ~2.5m, but the features in the 0-2m depth can be captured in sufficient detail. More importantly, patterns in the data including evidence of only a thin till horizon (<1m) and stratified deposits below it made the GPR data most useful by revealing areas where disruptions to natural patterns in these respective zones, possibly resulting from past anthropogenic or other disturbances are present. GPR data also revealed a prominent horizontal planar reflector within the stratified zone that is visible on several perpendicular transects, which when viewed in contrast to dominant natural stratification is suggestive of possible anthropogenic origin. Besides these useful insights we gained from the GPR data, we also discuss challenges of using GPR for archaeological research.