Tag Archives: Institute of Archaeology

Just too claggy

Anyone new to this blog or geophysics in archaeology is recommended to read the material on the “Geophysical survey in archaeology” page.

A group of us headed out to Little Hadham today with the aim of extending both the Earth Resistance and magnetometry surveys.   By the time Nigel had pushed the mag across the field, the wheels had diameters several inches larger than they should.  Jim tried a line or two of data collection, but the odometer was over-running by two meters and the wheel needed trowelling clean every transect.  We decided, therefore, to abandon the mag survey, and concentrate on enlarging the area of the Earth Resistance survey.  We managed another six 20x20m squares giving us a total of 100m by 80m, some 32,000 readings in total.

Figure 1, below, shows the initial results.  As before, the data is dominated by striping caused by the cultivation pattern.  A 2D fast fourier transform (as implemented in TerraSurveyor), quickly removed these stripes.

Fig. 1: the Earth Resistance data overlain on the mag data.

In Figure 2 I have applied the filter to remove the striping.  To the right I have put the mag data for comparison.

Fig. 2: The resistance data after processing with the 2DFFT. The mag data of the same area is shown to the right.

Unusually, most of the features show in the res and mag data.  The res data has nicely picked-up many of the linear features more normally only clearly seen in mag data.  In Figure 3 I have labelled a few points.

Fig. 3: the res and mag data with labels.

Ditch features A and B show nicely in both the res and mag data.  What is clear from the res data, however, is that the ditch continues between the two and they are one distinct linear feature.  If one draws a straight line along A and B, it lines up perfectly with the linear feature C we found across the road in 2014.   Linear feature D shows equally well in both data sets.  At E, something complex is happening.  In the mag data it looks almost as if A is turning and runs alongside E, whereas in the res data is looks more like AB cuts across the linear to the west of E.  The parallel lines to the west of E show quite well in both, and are probably some form of trackway.

Many thanks to Jim (CVAHS; both for surveying and transporting the equipment and myself), Nigel (NHAS), Caroline, Peter, Amanda and Mark (BAG).  Hopefully we can get to do some more when the field is less claggy.

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Infamy, infamy (they’ve all got it in for me)?

Those of you who know Bloomsbury probably imagine I have a lovely view across one of the squares from my office window. Until recently, you would be right!  UCL are building a new student hub (everything is a ‘hub’ these days) and had to have somewhere to house the workers.  The solution? … a two storey stack of portacabins in a tunnel over the pavement.

The Institute of Archaeology, UCL.

The Institute of Archaeology, UCL.

Just to add to my joy, the staircase between levels is just by my window, so they have covered it in plastic…

The view from my office.

The view from my office.

It is scheduled to be like this until December 2018.  No wonder I prefer being out surveying. Jarrod Burks, who many of you will remember from the course, was out surveying the other day.

Jarrod surveying, December 2016.

Jarrod surveying, December 2016.

Seems a bit too extreme for my liking!

You may wonder what this tale of woe has to do with geophysics and CAGG?  UCL have put up a nice set of panels on the hoardings to advertise what the Institute does and to make the place slightly more inviting.  I was really pleased to see…

The Verulamium survey on the hoardings.

The Verulamium survey on the hoardings.

Yay, fame at last!  Sadly, the only caption near the image of our survey doesn’t mention CAGG, Verulamium or geophysics.

The caption.

The caption.

Oh well, never mind.  Perhaps I should find a plastic holder for our CAGG postcards and leave a few there for the curious.

Local Hertfordians maybe interested to see the article on Batford in this week’s Herts Advertiser and compare that to my posting about the survey.

Merry Christmas everybody.