Geophysical Magnetometry Survey at Willowfields Energy Park, Kingston Bagpuize, Oxfordshire

The survey was undertaken using four Bartington Grad601 sensors mounted at 1m intervals onto a rigid carrying frame allowing for a 1m traverse interval. The system was programmed to take readings at a frequency of 10Hz (allowing for a 10-15cm sample interval) on roaming traverses spaced 4m apart in order to secure comprehensive coverage. The magnetometer system was linked to a Trimble R12 Real Time Kinetic (RTK) differential Global Positioning System (dGPS) outputting in NMEA mode to ensure a high positional accuracy of each data point; +/- 1cm for each reading. The data was stored on an external weatherproof laptop and later downloaded for processing and interpretation. Anomaly GeoSurvey v1.12.3 (Lichenstone Geoscience) and QGIS v.3.28.5 software was used to process and present the data respectively. A well-defined area of archaeological activity, comprising a large rectilinear enclosure with a smaller internal enclosure and numerous discrete internal features, has been recorded in the south-east of the northern field. This area of activity clearly maps the full northern extent of a dense area of probable settlement activity recorded by a previous survey. Traces of ridge and furrow ploughing, two areas of likely quarrying and modern ploughing trends have also been recorded in this field. Much of the central part of the southern field was still unsurveyable due to waterlogged and flooded ground conditions. No anomalies of archaeological potential were recorded across the remainder of the field with only linear trends indicative of modern and post-medieval ploughing being recorded. The receptivity of the sedimentary bedrock to magnetic survey combined with an absence of overlying superficial deposits suggests that the survey has provided a reliable indication of the archaeological potential of the site. Consequently, the archaeological potential of the northern field is assessed as very high in the south-east but low elsewhere. The potential of the southern field is assessed as low throughout.