Successful first gradiometer survey

Last weekend a group of AVAS members undertook their first gradiometer survey using equipment borrowed from Bournemouth University.  The equipment is being lent out to local archaeological groups as part of a project called LoCATE (Local Community Archaeological Training and Equipment), which is a partnership between the Archaeology Department at Bournemouth University and the New Forest National Park Authority.

The site was between Salisbury and Ringwood in the Avon Valley.  The field in question contains a distinct ploughed out mound about 60m long in a field now used for pasture.  We did a resistivity survey here in 2011, which picked out the shape of a regular long mound, but failed to locate any possible ditches;  the jury was out on whether this was a long barrow.

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After locating the fence posts used as survey points for our 2011 resistivity survey, we soon had our grid squares set out.  It took a little while to calibrate the gradiometer, but we were quickly able to complete a couple of squares.  We took a break to download the results.  The bright sunshine meant it was difficult to see the laptop screen, but we could make out a couple of distinct lines which appeared to respect the mound.  It looked like we might be picking up two ditches.

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Mark and Jan undertaking the survey. This photo also shows the mound, which is hiding the car to the right.

We were able to rapidly survey another four squares, with a short break for lunch.  I had downloaded the results for the first four squares, and the results looked promising, but again it was hard to see on the laptop.

On trying to exit the field, our way was blocked by an angry herd of bulls, but Rachel was braver than me and jumped over the gate to encourage them out of the way.

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I rushed home in eager anticipation.  How clear would the results be for all six squares?  I was blown away by the results when they appeared on the computer screen, as shown below:

Gradiometer results

Gradiometer results

The plot shows two long wide anomalies that appear to be outer ditches.  However, what was totally unexpected, and hadn’t been clear when reviewing the results in the field, was the trapezoidal shape positioned between the ditches.  This is a classic long barrow shape, and clearly resembles the plan of the excavated long barrow of Fussell’s Lodge, near Salisbury:

Plan of Fussell's Lodge long barrow

Plan of Fussell’s Lodge long barrow

In the case of Fussell’s Lodge, the trapezoidal shape represented a bedding trench used to hold timbers which acted a s a revetment for the mound.

Our first venture out with the gradiometer had been a huge success.  We now need to extend our survey area to pick up the full shape of the outer ditches.  Many thanks to Bournemouth University for lending out their equipment, and to the New Forest NPA for hosting the equipment.  See our the AVAS Flickr feed for more photos.

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One Response to Successful first gradiometer survey

  1. Jolyon Crane says:

    Wonderful to see such clear and impressive results on the first outing.Congratulations

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