Keele Research Repository

Graveyards and cemeteries around the world are increasingly being designated as full. There is growing requirements to identify burial space or to exhume and re-inter if necessary. Near-surface geophysical methods offer a potentially non-invasive target detection solution, with additional soil sampling analysis to provide ground truth information; however there has been lack of research to identify optimal detection methods. This study has collected multi-frequency (225 MHz – 900 MHz) ground penetrating radar, electrical resistivity, electromagnetic induction and magnetic susceptibility surface data over different burial scenarios (ancient, old and modern burials). Surveying ancient burial sites revealed they can be geophysically detectable even after 650+ years of burial, given optimum local soil type and depositional environment conditions. Surveying old and modern burials indicate that progressively older burials are more difficult to detect but complicated by local soil type. Different geophysical techniques were optimal in different sites, which therefore suggests a multi-technique approach should be utilised by survey practitioners. Graveyard geophysical targets included the grave soil above graves themselves, the grave contents, brick-lining (if present) and grave soil water that can be all detectable from background levels. Grave markers were also identified not to always be located where burials were positioned. Buried cadaver decomposition releases elements into the surrounding soil, which can significantly change the local site geochemistry. Resulting elevated element levels, associated with cadaver decomposition, can assist in identifying burial location(s), when compared to background levels and temporally vary. These included inorganic elements, pH and conductivity. Potassium, sulphate, sodium and phosphate were also identified as potential grave markers, which also showed strong correlation coefficients with grave soilwater conductivity values. Background elemental concentrations were consistently low and were controlled by rainfall.