Mystic lines of power

The contour plot I was working on last week for the bank and ditch in trench C is finally finished. I’m very pleased with this because it has given us a completely different view of the main enclosure ditch. The contour lines in the two images are at 0.1 m intervals. They were calculated from something like 250 spot heights measured on site while the plans were being drawn. This is a great example of how important data you record on site can be when you finally get around to analysing it. Levels, or spot heights, on plans are something that all archaeologists always record automatically. We didn’t take these measurements because we suspected they would prove something, we took them because it is the standard procedure. Of course standard procedures get adopted because years and years of experience has shown archaeologists that sometimes you get valuable data from them.

This first plan shows trench C once all the deposits had been removed – the same stage as the photo taken on the final day. It shows the top of the natural subsoil and the form of the ditch as it cuts that subsoil. On site, while we were digging and recording the ditch, all we noticed was the obvious fact that the rock-cut base was extremely irregular. What we were missing, as we slipped and stumbled about on all the jagged limestone, was that there was a definite shape to the part of the ditch we dug. As the contour plot clearly shows, the south side of the ditch is much shallower. There appears to be a curved end to the deeper part of the ditch, as if this deep ditch only comes part of the way across the trench.

This kind of thing is actually fairly common in prehistoric ditches. It is very likely to mark the point where one segment of the ditch joined up with another when it was being dug. This might be because the ditch was dug in stages over several years – I know I would want several years at the job if I had to dig a ditch up here with only wood and antler tools. However, we didn’t see any evidence that any one side of the ditch was dug first when we were excavating it. It may be more likely that the ditch was dug as a single event but that different gangs of people were working on different segments and our ditch marks the point where two of these gangs joined up their efforts. Imagine them dragging out the last basketful of limestone rubble and shaking hands across the gap like Victorian engineers finishing a tunnel.

The bank is less exciting: although despite how shallow and eroded it was you can see a clear difference in the contour plots, especially the 20 cm rise on the inside face of the bank. One thing to note is that the contours on this one have been updated but the plan underneath still shows the rocks on the surface beneath. I’ve only just noticed that. Still, work in progress and all that, I will sort it out eventually. The main lesson from this week is that if you to stick to your recording procedures on the dig all kinds of lovely details can pop up months later to add to your knowledge of the site.

Still no more finds plots I’m afraid, although I did get to watch The Princess Bride again this afternoon, therefore the wildlife of the day is: Rodents of Unusual Size.

Rick

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