Geophysical survey at the 3 sites commenced using magnetometry investigating all available lands, with secondary EMI survey at select locations.
The 2 greyscale images below present part of the magnetometry results from geophysical survey of the Vicus site, to the west of an existing road (Greyscale 1), and at the south-eastern limit of the investigation area (Greyscale 2).
Magnetometry Greyscale 1
The 1st magnetometry greyscale details a dense linear arrangement of large posthole, pit and small ditch remains recorded along the route of the north-east/south-west Roman road. These anomalies detail just a small part of the Vicus settlement (which is now traversed by an existing road), and highlight remains of earthen buildings sited along narrow streets with outlying remains to the west. The route of the Roman road is discernible in the eastern portion of the greyscale as a channel of relatively ‘quiet’ magnetic north-east/south-west response. To the west and north-west shallow negative linear and meandering anomalies traversing the magnetometry results represent defences at the perimeter of a WW2 bunker.
A dense scatter of Roman pottery and roof tile fragments were recovered during previous fieldwalking across this part of the study area. No further surface visible remains of the Vicus were evident at the time of fieldwork.
Magnetometry Greyscale 2
The 2nd magnetometry greyscale highlights the linear remains of the north-east/south-west Roman road at the western edge of the existing road. The existing road has contributed large-scale magnetic interference, as has passing traffic, modern fencing and an existing dwelling. To the east part of a walled rectangular enclosure containing 1 clearly defined small building marks the location of a possible mausoleum or temple like structure. The enclosure is approximately 55m x 35m in diameter, and the small building it contains c.5m x 3m in size. The western portion of the walled enclosure lies beneath the existing road. Disturbance from more recent boundaries, fencing, and a dug-out modern access to the north-west also traverse the data set from this section of survey.
No surface visible expression of these buried remains was evident at the time this magnetometer survey was conducted.
The 2 greyscale images above detail just a small part of the entire magnetometer survey of the Vicus site. In its entirety the magnetometry highlights the Vicus remains actually extending c.850m along the route of the existing road and c.200m to the east and west.
The results from magnetometry and EMI are now being used by the client to assist the requirements of their ongoing project. As a means of identifying the exact location and extent of a till now largely un-investigated national monument in Flanders this magnetometer survey has proven highly successful. This success is largely due to the high resolution and precise positioning of the geophysical data collected during this project.
Instrumentation and methodology
6 sensor magnetometer cart system with GPS, 8-10cm sample interval, line/sensor separation 0.5m
Geonics EM38 conductivity meter combined with GPS, 8-10cm sample interval, line separation 0.75m
Positioning of all data in Belge Lambert 72 (20-40mm precision of position)
Loams (Aba1, Aca, Acp); sands (Zbx); clays (U-A-S).
Many thanks to both David Depraetere (VLM) and Elke Wesemael (ARON bvba), who provided invaluable support during both the course of the fieldwork and reporting for this project.