The parallel multiple striations are the gradiometer's response to plough furrows in the soils which have a locally high level of magnetic susceptibility. A number of further elements of probable prehistoric date were detected in the vicinity of the barrows by a combination of topsoil magnetic susceptibility mapping and gradiometer scanning. Very little survives of the walls due to stone robbing. There is evidence that some walls are still partially intact. Pockets of material having relatively high magnetic susceptibility can be seen to be trapped within the walls.
Nothing is visible of either building on the surface.
Jurassic limestone, some alluvial deposits. If this trench contains material of sufficient magnetic contrast to produce a local magnetic anomaly the original ground plan of the building will be apparent on a detailed gradiometer plot. Normally the anomaly generated by the 'robbing trench' will be positive where topsoil or other material of relatively higher magnetic susceptibility infills the trench. The thermoremanent properties of fired clay also make brick walls and buildings a suitable target for magnetic survey. Structural elements built of of fired clay products are also responsive, notably the hypocausts of Roman buildings, together with fired clay flooring tiles and concentrations of fallen clay roof tiles.