Anyone new to this blog or geophysics in archaeology is recommended to read the material on the “Geophysical survey in archaeology” page.
Firstly, apologies to those waiting for the results of the GPR survey in the churchyard at Ashwell undertaken just before Christmas. I need to do some more data processing to see if we have some graves or not.
Meanwhile, the site at Little Hadham has been one to which we have returned on-and-off almost since the beginning of the project. (Use the drop-down box on the right of this page to see previous posts on this site.) The site clearly extended beyond the area we had surveyed so far, and so CAGG once more teamed-up with members of the Braughing Archaeological Group (itself part of the East Herts Archaeological Society). We could only access one of the fields, the one we first surveyed in April 2014. Our aim was to extend the survey to the edges of the field, and to examine one group of features we had detected with the mag previously with an earth resistance survey.
The morning was cold and crisp with a hard frost. The thermometer in Jim’s car registered minus 3 Celsius. Brrrrrr… Unfortunately, the frost melted quite quickly and muddy wheels on the mag became a problem (Fig. 1)!
The mag team completed six grids, five of which were partials. Given the amount of time spent trowelling the mud off the wheels, this was a good haul. We have four partial grids left to complete the field. The results are given in Figure 2.
The areas completed yesterday were the block to the far east of the survey area, and the incomplete strip of partials on the southern edge. In the new area we can see the ditch previously detected (shown by the red arrow) carrying on across the site. It is fainter in Millfield to the west of the road, but is still evident. Near the hedge is another clear line of a ditch (marked with the yellow arrow). This one is worryingly straight and almost parallel to the field boundary. It maybe more modern than some of the other features. The curvy, more irregular ditches (shown with the blue arrow) may be something like a farmstead with boundary ditches. Picking apart the phasing of all these features is going to be difficult and would require some targeted excavation.
As we had a good sized team we also undertook some Earth Resistance survey (Figure 3). We targeted one of the possible farmstead enclosures.
The team completed five 20x20m grids at a 0.5m reading spacing. The results are shown in Fig. 4, and the underlying mag in Fig. 5.
I had been hoping — rather optimistically — that the resistance survey might pick-up some structures. Sadly, it did not. There are, however, correspondences between the mag and res results. The ditch with the right-angle corner in the mag survey shows well, if slightly more diffuse, in the resistance data. Similarly, the long curving ditch also shows well. I have indicated one end of it with a blue arrow in Figure 6.
More curious, however, is the change from low to high resistance along a straight line indicated with a red arrow in Figure 6. This corresponds exactly with the diagonal line in the mag data which cuts east-nor-east west-sou-west across the D-shaped enclosure. I’m at a loss to know what this represents. It maybe a reflection of the various cut features in the underlying geology.
At the end of the day we were treated to a beautiful moonrise and sunset. Not quite the blood wolf moon seen some 12 hours later (when I was tucked-up and asleep in bed!).
Many thanks to everyone who turned-out on a freezing but beautiful day. This site continues to repay our attention, and it worth the effort. We should try and survey some of it in the summer, however!