Exhumation of Yagan's Head - The Geophysical Survey

The Geophysical Survey

In 1997, two brothers, Dr Martin Bates of the University of Wales, Lampeter and Dr Richard Bates of the University of St Andrews, were commissioned by the Home Office to conduct a geophysical survey of the grave site, with a view to exhuming the remains via an adjacent plot without disturbing any other remains.

The pair conducted surface surveys using ground penetrating radar and ground conductivity techniques. The ground penetrating radar yielded no information about the location of Yagan's head, as the highly disturbed graveyard soil contained many reflecting sources. However, the ground conductivity measurements showed an anomaly in the electromagnetic signature that it was thought might be caused by metal artifacts buried with the head. The apparent location of the remains confirmed the feasibility of accessing them via an adjacent plot.

A pit was then dug in an adjacent plot, to a depth of around six feet, and a vertical ground conductivity test was conducted from within the pit. This test failed to detect the anomaly recorded in the surface test, however the conductivity plot did show an anomaly at the centre of the grave, indicating that the grave was dug to its full depth of nine feet only at its centre. This suggested the burial of a small box, confirming the memory of the grave digger who claimed to have constructed a small box to house the buried remains.