Techniques employed:

Resistivity
Magnetic Susceptibility
Magnetometry

Client: David Sabin

Geophysical surveying carried out by Stratascan helped David Sabin, who was Stratascan's Archaeological Project Manager at the time, carry out research at a Romano-British villa site in South Warwickshire. The site was initially located by David in 1998 after a programme of fieldwalking in the area. Tesserae collected from the field surface indicated the presence of a mosaic floor that was being heavily disturbed by ploughing. A 'rescue' type excavation was carried out in September 2002 with help from the Association of Roman Archaeology in order to assess and record any surviving mosaic floor.

The importance of this site became obvious as a largely intact but very heavily disturbed mosaic was discovered. The area is approximately 4.5m x 4.5m This becomes only the second site in Warwickshire to have had an intact mosaic floor recorded. Further assessment of the site was required in order to help the landowners manage and protect the archaeology. From the distribution of material located by fieldwalking it was initially thought that the archaeology was contained within a relatively small proportion of the field. Geophysics was used as an attempt to define the villa building and any associated structural remains within the immediate vicinity. Resistivity was considered the most suitable technique for locating any surviving wall footings and excellent results were obtained from a survey carried out in October 2002.

The Pillerton Priors mosaic. Photograph © Luigi Thompson

The resistivity survey has revealed an L shaped building and shows internal walls giving a good indication of the internal layout of the villa. There are few anomalies outside of the building that can be identified although a wide linear feature to the south may be the location of a palaeo-channel.

With such a large area to survey it was decided to use magnetic susceptibility as a reconnaissance technique following up with detailed magnetometry targeted on areas with high readings. Currently this surveying is ongoing but there are already some useful results.

Approximately half of the field has been surveyed with magnetic susceptibility and areas of high magnetic enhancement around the known position of the villa have been targeted with detailed magnetometry. The magnetic susceptibility survey was carried out using 10m centres with detailed magnetometry collected at 0.125m centres along traverses 1m apart.

From the results so far an area of high magnetic enhancement corresponds well with the position of the villa and within the immediate vicinity of the building. Areas of high magnetic enhancement towards the south of the field appear to produce an almost linear response that correlates with a wide linear anomaly located by resistivity. The origin of the feature is unknown but may be a palaeo-channel.

Detailed magnetometry targeting an area over the villa has produced interesting results that improve understanding of the development of the site and help to develop ideas about activity within the immediate vicinity of the villa building. Resistivity and magnetometry results have provided complementary details of the archaeology at this site without further need for excavation.