Test pit 47 measured 1m x 2m test pit and was excavated on rough grass immediately to north of Northfield School football pitches and to the south of the present day course of the Northfield Brook.  This area was open fields up until the construction of the school in the 1960s.The test pit was targeted to investigate an anomaly discovered by a previous gradiometer survey in summer 2011 (more information).It is considered likely that the circular feature identified from the previous geophysical survey and aerial photographs represents introduced ferrous material within the make-up /levelling layer (501-503) in the 1960s while football pitches were being constructed.  It is not, as considered in original gradiometer report, a Roman or prehistoric feature.  The top of layer (504) represents the original ground surface prior to the construction of playing fields.  Layer (504) is part of an extensive peat deposit associated with the Northfield Brook.  Similar deposits have been encountered at the Kassam Stadium site, Ozone Leisure Park, Minchery Farm Paddock and Oxford Science Park to the west of Northfield School.

Full report