USING SHALLOW GEOPHYSICS TO RECONSTRUCT HISTORIC INFRASTRUCTURE AT BENJAMIN HUBBARD HOUSE, WILKES COUNTRY, NORTH CAROLINA

The Benjamin Hubbard House near Moravian Falls, North Carolina is listed on the National Register of Historic Places as a well preserved 1778 side-gabled log house with additions in 1790’s and around 1870. This house represents pioneer life in western North Carolina and has remained within the Hubbard family. However, in 1937 most of the outbuildings and an addition on the rear of the house were removed due to their dilapidated condition. In our study, we investigated the area immediately surrounding the log house using ground penetrating radar (GPR) to detect evidence of these former structures. The targeted structures, integral to farm life during the period were identified from a sketch map drawn from memory by a descendent. The structures included a smokehouse, an ash hopper, a wash house, and the kitchen addition with a fieldstone chimney.

In November 2021, we collected 3 grids (9201ft²) along the north and west sides of the log house using a GSSI UtilityScan GPR System with a 350 mHz hyperstacking antenna. The GPR data were processed using GPR-Slice software for 3-D imaging. The data processing steps included correcting for time zero, applying an automatic gain control and a background removal filter. A rectangular area, 6 x 20 ft of high amplitude reflections on the GPR depth slices imaged the footprint of the wash house. Probing in this area determined that these reflections are from a gravel or stone floor. GPR profiles show a linear depression 2 ft wide, 8 ft long and about 1 ft deep extending off of the east side of the wash house. The sketch map shows an ash hopper for lye production east of the wash house. Two corner stones representing the south side of the smoke house were imaged on the GPR depth slice. The 8 x 25 ft footprint of the kitchen addition was observed by a discontinuous pattern of medium amplitude reflections. An isosurface rendering of the reflections and radar profiles on the east end of the addition clearly image the base of the former chimney. These features and additional radar anomalies will be further investigated using a magnetic gradiometer and direct-current electrical resistivity tomography to supplement our GPR imaging. This project illustrates the benefit of combining geophysics with historical archaeology to interpret the past.