On the 26th of March, 2009, Adjunct Associate Lecturer Ian Moffat gave a seminar entitled the Geophysical Detection of Historic Graves. The seminar room was filled with forty-one (41) fellow academics and students from the Department of Archaeology.
The seminar focused on the effects of geology on current grave detecting methods such as the magnetometer and the ground penetrating radar. There are three divisions of burials or graves; the Indigenous, the Clandestine, and the Historic. Ian’s case studies were focused on the latter division which included the Selheim Cemetery (North Queensland), the Pioneer Park Cemetery (Adelaide), the Encounter Bay Cemetery, and the Meadows Cemetery (Adelaide Hills).
The Selheim Cemetery was the most successful of the four case studies with the rediscovery of all thirty previously ‘lost’ burials. Both the Pioneer Park and Meadows Cemeteries case studies produced good quality data but the amount of time used was a minor setback. Geology and its effect on burial data analysis was profound in both the Encounter Bay and Meadows Cemeteries. The heavy vegetation in Encounter Bay and the sandy conditions at Meadows Cemetery have deterred the geophysical survey process.
Some of Ian’s conclusions at the end of the seminar were:
- the magnetometer and EMI methods are greatly affected by the presence of surface metal
- decrease in line spacing of GPR data leads to substantial increase in the ability to detect burials effectively
- GPR is more effective in sandy locations than in clay (contrary to previous studies)
- the greater the number of trees on the site, the slower and less effective are the geophysical methods
Even though I do not have an archaeology background, Ian’s presentation was very organised and was not too difficult to comprehend. His research and conclusions were well-received with various questions and comments from at least eight people in the audience.