Geophysics in support of industrial archaeology in a challenging environment: Shade iron furnace, Pennsylvania, USA

Abstract

AbstractThe value of geophysical methods in investigating iron furnaces in North America (of which several hundred exist) has so far been poorly evaluated. We report on the magnetic gradiometer and electrical resistivity surveys conducted at the Shade iron furnace, Pennsylvania, USA, together with results from ground‐truthing excavations. We find that (i) numerous useful data sets could be recorded despite challenging field conditions; (ii) reconnaissance gradiometer and resistivity data yield complementary information allowing large‐scale site reconstruction; (iii) high‐resolution resistivity data reflect archaeologically valuable site lithologies with decimetre‐scale accuracy; and (iv) extreme absolute background values (several hundred nT) of, and spatial contrasts (several hundred to > 1000 nT) in, the gradiometer data are common owing to the presence of much burnt material and iron artefacts. We conclude that geophysical investigations of iron furnaces in North America may yield spatially extensive subsurface information of substantial archaeological value, which is impossible to obtain using traditional archaeological survey methods alone. Copyright © 2004 John Wiley & Sons, Ltd.