Resistivity is another survey technique we used. Unlike the Tape & Offset survey a resistivity survey is one which indicates what is below ground – so you can see into the soil as it were.
This kind of survey comes under the umbrella term ‘geophysical survey’ or ‘geophys’. If you’ve Time Team you’ll know what’s involved. Resistivity, as it names suggests, measures resistance to a small electrical current passed through the soil. The resistance to this current is measured and plotted.
Everything has some resistance to an electrical current but there are subtle differences to be found. For example, ditches are filled with material that has been churned around and mixed up. This means that they hold a lot of moisture in the soil than the undisturbed soil around it. This moisture content has less resistance to the electric current In the case of walls or stoney areas content have less whereas walls and stones have much more. So, like the magnetometry, this technique should’ve helped us locate any missing buildings as well as other past activity.
Our resistivity survey was carried out in April 2019 and we were really excited to see the results! We could see a number of possible features in the plots provided by Richard & Angela Kniseley-Marpole. The short version is that there appeared to be four linear features running parallel to each other. It was also reassuring to see that some of these had a ‘return’, that is they turned at a right angle. So, had we found the hall? Well id you want to read more download the report.