Ground Penetrating Radar

Date 25 November 2015 - 28 November 2015

Event ID 1023859

Category Recording

Type Ground Penetrating Radar

Permalink http://canmore.org.uk/event/1023859

NT 59587 85029 A programme of geophysical survey was carried out in 2013 which identified a wealth of significant anomalies, many of which have been targeted in subsequent excavations. A ground penetrating radar (GPR) survey has been carried out, 25–28 November 2015, over selected areas to further refine and inform interpretation.

Within the outer close several trends and ephemeral anomalies suggestive of a possible broad ditch on an E/W alignment are evident within the N of the area. The data also suggests remnants of possible rig and furrow cultivation. Given these discrete anomalies and broader areas of increased response, it appears that some of the anomalies detected in the previous resistance survey may be the result of different phases of activity, rather than contemporaneous features.

Although numerous very strong anomalies have been detected within the ravelin area, many are associated with the extant earthworks. Variations in response over the ravelin bank may indicate areas of reconstruction. The survey has added more information regarding potential features within

the ravelin. However, the data from the outer ditch is not conclusive. No clear profile is evident suggesting a very shallow feature.

Survey of the crossing points over the main ditch behind the ravelin proved disappointing. There are no clear suggestions of structures within these earthworks consistent with buried caponiers. However, the survey may have revealed an earlier profile of the northern crossing point and the lack of response from the southern crossing point may itself be significant.

Archive: Rose Geophysical Consultants

Funder: Historic Environment Scotland

Susan Ovenden – Rose Geophysical Consultants

(Source: DES, Volume 17)