Site Event/Activity record ECH6630 - Geophysical Survey, Edgar's Field, 2014-2015

A resisitivity geophysical survey was undertaken in 2014-2015 of an area of Edgar’s Field, Handbridge, as part of a research project by David James Laverty, a student of the University of Chester. The project investigated Mithraism in Roman Britain, focusing on a re-assessment of the archaeological evidence for the worship of Mithras in Chester. The research identified Edgar's Field as a potential likely location for a Mithraeum in Chester. This was based on known Mithras-related finds in Chester (a figure of Cautopates is reported to have come from the area of Edgar's Field, CHER 8430/24) and a spatial analysis of known Mithraic temples in Britain. As with other known Mithraea in Britain, the site lies south-west of the fortress and close to a natural water source (River Dee). Edgar's Field is also the site of a Roman quarry (CHER 8449/2) from which many of the fortress stones were quarried. Lidar data shows a depression in front the quarried rock outcrop which also has a shrine dedicated to Minerva carved into it (CHER 8449/1). This depression was interpreted as potential below-ground structures which had collapsed, accordingly, a resistivity survey of a 30m by 20m area, over the area of subsidence, was undertaken. Interpretation of the results identified a series of three potential regular, rectangular features/structures. In the smallest rectangle, high resistivity was recorded throughout, suggesting a hard paved floor or rubble. The entire 'structure' is orientated north-east to south-west, similar to Mithraea found at London, Housesteads and Carrawburgh, with the dimensions of the inner two rectanglular features being similar to all but the London Mithraeum. (1)