A geophysical survey was conducted over an area of 9600m2 in the south-west corner of the survey field. The survey area was 60 metres wide and 160 metres long in a large field adjacent to the River Idle. The survey was commissioned as a result of the presence of numerous microliths and other mesolithic flint artefacts in a previous field walking survey. The field survey also produced Roman, medieval and post-medieval pottery, and assorted metal artefacts. This survey was conducted as part of a structured evaluation of this area prior to quarry expansion. The baseline ran approximately north-south. In total, 24 squares (each 20m x 20m) were covered by a magnetic susceptibility survey, covering a total area of 9600 square metres. Surface readings were taken every 1 metre. In addition, where T&PAT test pits were located, readings were taken from the subsoil. Neither the surface survey nor the subsoil readings show any clear indication of individual hearths. The area, particularly the northern half, exhibits considerable surface contamination. Once this is accounted for the variation in readings appears much more likely to be related to the underlying drift geology than to any archaeological features. As the entire area is underlain by a sandy deposit, two zones may represent deeper areas which have had a greater build-up of relatively organic-rich deposits, while another zone may have been a sandbar or ‘island’ before modern drainage of the area and canalisation of the river.