31 March 2012

Latest Results: Rocky Clump

For those of you who haven't heard of Rocky Clump (i.e. not Sussex archaeologists), it's a Roman farming settlement near the city of Brighton that has been under excavation by the Brighton and Hove Archaeological Society for the past billion years (or so it seems). Not quite as rich as a villa, but interesting nevertheless. The site is famous for a vast array of ditches that seem to make no sense, and some sarsen stones in a clump of trees after which the site is named. After several years digging up ditches to the north of the clump, BHAS started digging to the south in 2011. Many, many years ago, I did a large resistivity survey in the south field which showed up a large number of features, which you can see the results of below. Click the image for a larger version.

Whilst there is a lot going on in the image, a lot of it is geological. Readers of this blog may remember a post I wrote about an annoying form of geology known as clay-with-flints. This nasty stuff will make you think you have features everywhere, until you dig them up. There is an upside though. Normally magnetometry will not work on chalk, as there are no magnetic particles in the soil to form a contrasting reading when a ditch cuts the geology. The presence of the clay-with-flints introduces those magnetic particles, allowing magnetometry to work. I resurveyed part of the field today, to see if I could work out which of the features were geology and which were archaeology. You can see the results below.

Just look at all those lovely ditches. There is a small settlement enclosure in the middle, possibly within the corner of a field boundary. The ditch to the north that was visible on the resistivity is also visible on the magnetometry, but the large low resistance area that it passed through is now looking like geology, but I can't be sure about that. Further to the west are three ditches, one of which takes a curve to the south, and a possible east-west trackway formed by two further ditches. Of the two large low resistance features near the clump, the north-west one has transformed itself into a series of small ditch features and is most likely archaeological. The south-east one is a bit of a mess and is most likely geological, but again I can't be sure. There are plenty of dark blobs that represent the clay-with-flints, which stand in stark contrast to the fainter archaeology. One particular faint feature to take note of is just to the north-west of the settlement enclosure. It is about 6m x 4.5m, and could well be part of the settlement. BHAS have stripped the topsoil for a new excavation this year, which shows up well as a giant white reverse L shaped feature.

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