Day 4 - Stroud 'Big Dig' 2017
Today was the start of the second 3-day session of this year's dig at Stroud, and there was a reasonable turnout of members to take part - although the Heath project in Petersfield is luring away a few people. Perhaps this is understandable given the quality of some of the finds I have been seeing on Facebook!
We still have no resistivity machine, although thanks Keith Baker for getting the weld repaired during the week. So the focus today had to be on test pits and Juliet and I decided that the time had come to explore the lovely setting of 'SBF'. We had two main objects in mind:
To explore the orchard, marked on the tithe maps as 'Mill Platt', to see if there was any sign that there had once been a water mill on the two streams that run through the property; and
To see if there was any sign of the track that we think, based on LIDAR and marks on aerial images, may once have run from the Roman villa's gateway to the bridge by this property.
So we parked in a nearby field owned by Fiona and Mark - thank you both - and met Stuart at the house who kindly dealt with the important issue of allowing us access to one of the toilets. I also was able to meet Sarah for the first time, whose house it is. All of us then explored the orchard area looking for features while Barry helped by Jason did some metal detecting in the area.
What we found was:
There was no sign of any CBM in the two streams;
There was no indication of a mill race, and both streams were very wiggly with no straightened sections or suggestions of damming that you tend to see in a mill stream;
Despite the 'lumps and bumps' across the orchard, there was nothing to suggest the footings of a building.
Guided by this 1964 aerial photo of the property (with the orchard seen on the right of the image) we decided to start by digging two test pits: one in a lower section of the orchard, and another near the stream footbridge where we saw some white stones on the surface on what we thought to be one of the ridges you can see on the right of the photo.
We divided all the kit into two piles and Sally agreed to supervise one team and Liz the other. It was obviously very hard work for those lifting the turf because the soil is still very hard despite the recent rain.
Having marked out the two test pits and lifted the turf it very quickly became obvious in both that the soil appeared to be silt-like clay. It was heavy, lumpy, had hardly any stones and only one had tiny fragments of CBM that was obviously not Roman. Obviously disappointing but we went down to 20cm in a corner in both pits, found nothing else, so recorded, photographed, measured in and then infilled the pits. Liz's team did another pit about 2 metres away nearer the surface stones, but the result was exactly the same.
While all that hard work was going on I did a drone survey. The drone was on autopilot, flying a pre-programmed zigzag course at a height of 60 metres and taking a vertical image every 5 seconds across the whole of the property including the paddocks. The 146 images taken are currently being processed on a specialist website that creates a stitched-together 'orthomosaic' photo, as well as a height contour map of the site and a virtual model. This task takes over 3 hours to process so I still have a while to wait for the results.
Barry and Jason were meanwhile also touring the property but their finds too were not great - some iron items like those pictured below, some nails (quite old) and a tiny rolled-up strip of lead.
I also went across to visit Fiona and Mark Rowden in their house to thank them for allowing us to park in their field and also do geophys there, hopefully on Sunday.
By the afternoon tea break I think we were all feeling quite tired and a little disappointed at the lack of finding anything interesting. We chatted about the geology and from the BGS website it is shown as clay subsoil with surface deposits of hillwash clay and silt, presumably from when the orchard has been flooded and when the streams are full each winter. We also talked about our plans for what to do next - probably continuing to look at test pits in the paddock area at SBF and see how Oliver Howe is getting on with the oilseed rape harvest, due imminently but depending on the forecast rain.
Looking at the orchard now, and comparing it with the features on the 1964 aerial photo seen above, we have come to the conclusion that much of the orchard area has been landscaped in that last 50 years. We think that what has happened is that some years ago a wildlife pond was created in the orchard and that the soil extracted was probably spread over a considerable area, filling in many of the lumps and bumps seen in the 1964 photo and causing our test pits to consist mainly of what had once been topsoil.
After that we finished filling in the test pits, recorded everything and tidied our equipment away under tarpaulins ready for tomorrow.
The one thing we did find intriguing though is that in the orchard, at the end nearest the bridge, are three very large stones lying in the lawn that were largely covered in moss. They were not in any obvious pattern and were at different heights so it seems unlikely that they were footings for a building, so their origin and original purpose remains an enigma.
Hopefully better luck tomorrow!