Anyone new to this blog or geophysics in archaeology is recommended to read the material on the “Geophysical survey in archaeology” page.
Before looking at today’s results, I thought everyone might be interested in seeing the reaction to our survey at Verulamium at the Near Surface Geophysics Group conference last December. Not being someone who twits, I hadn’t realised that a webpage of postings from the conference had been put together at https://storify.com/girlwithtrowel/tweets-from-the-nsgg-recent-work-in-archaeological You have to scroll down a long way, but look out for the comment by Magnitude Surveys.
Today saw the GPR crew tackle an awkward block that has the hedgerow half way across it. Here are nine time slices from it.
There are some very clear buildings. Look, for example, at slice 7 (right hand column, middle slice). In proof of the only universal law, look at the first “sawtooth” on the south side of slice 8 (bottom left hand corner). There is a lovely little apse just peeping out into the plot. Typical… the building is under the hedge.
Let us see where this block fits in the overall GPR survey (Fig. 2).
The absolute area we have now surveyed is quite impressive thanks to the efforts of members of CAGG. Well done all. Let us now have a look at a couple of time slices from today.
The fourth time slice (Fig. 3; roughly 0.4 to 0.5cm below surface), mainly shows the road running diagonally SW to NE. The cross-roads just to the north of today’s block is a very busy locality with lots of buildings clustered around it. The block just to the south of today’s survey also has some pretty substantial buildings.
Time slice 8 (Fig. 4, roughly 0.8 to 1.0m below the surface) shows some of the buildings alongside the road to the south of the hedge line. The road is squeezed in between the building found earlier in the block to the south and the new rooms found today. We also have a little more of the building to the west. The two lonely walls in the southern block would seem to be related to that building too. All-in-all, some very nice results.
The Earth Resistance team of Ellen, Pauline and Graham headed north to tidy-up the top-edge of last year’s survey. They managed a surperb eight 20x20m grid squares. Here are the results.
As can be seen, especially from Fig. 5, we have picked-up some more details of the nice large building in the middle of the plot, as well as other buildings such as the small one at the western end of the strip of grid squares. At the eastern end we have a large square high resistance feature. A surviving floor, perhaps?
Fig. 7 shows the mag data from this area.
Not much sign of the small building to the west, or the “floor” to the east in the mag data, although the “floor” seems to be associated with quite a few walls.
The “sinuous ditch” cuts across the line of today’s plot (seen as the broad dark linear feature entering Fig. 7 top centre, and heading to the SE). This is almost certainly the town aqueduct as it lies along the 300ft contour. Comparison to Fig, 8, however, shows we we do both mag and res… no sign of the aqueduct in the res data at all.
One last push tomorrow and we are “done” at Gorhambury for 2017. Many thanks to everyone who has worked so hard, and also thanks to the Earl of Verulam for allowing us access.