Today saw a fair sized group for the start of the survey of the Gorhambury side of Verulamium. Having completed the Park side of the Roman town in January 2014 we were keen to do the other half. Our thanks are due to the Earl of Verulam for not only allowing us to work on his land, but for acting as intermediary on our behalf between the various ‘stakeholders.’
We are going to be running the magnetometer mainly, and will aim to do as much of the town as we can. The first day was a little bitty and the rain didn’t help, but we have already got some nice results.
The temple which lies to the SW of the theatre shows in the mag data to the west of our blocks, but only faintly, The large black ‘blob’ is very interesting. It is about 8m across and ranges from -7 to 24nT. A big pit, maybe? The dark linear feature clearly runs parallel to the walls of the temple, but again, what is it? It is about 10m long and is quite magnetic with a range of -11 to 36nT. Near the middle of our plot are a series of white lines representing buildings with flint footings cut through more magnetic material, either burnt or very organic. These are probably the footings of buildings already known, although seem here in more detail (M451–454 in Niblett and Thompson Albans Buried Towns). Not bad for the first day!
As well as the magnetometer, we have the use of SEAHA‘s Mala Ground Penetrating Radar and will be running that alongside the mag. It is much slower as it is only collecting one line of data for each pass, not four, but as we have seen before, combining the mag and GPR data can be very useful. We collected 128 lines of GPR data today, but I haven’t had time to process them yet. Watch this space. Finally, we are also collecting some resistance data but that is even slower than the mag. It is good, however, to be able to combine multiple data sets.
Watch this space over the next three weeks to see how far we get!