Geoarchaeology at the Bradford Kaims

Becky Scott – Assistant Supervisor (Geoarcheology) and PhD Candidate, University of Reading

Following on from our blog post about the geophysical survey carried out at the Kaims this year, we have been busy ‘ground-truthing’ the anomalies seen just to the North of Trench 6 – that is, identifying whether the magnetic anomalies seen on the survey are archaeological features or not. Of course, like most endeavors, we have had varying degrees of success! The first few test pits that were dug contained nothing but colluvium (sediment that has been deposited downslope, often known as hill or slope wash) even after digging up to a metre. We then decided to take some cores around the area that showed the magnetic anomalies to the North of Trench 6 using the Dutch auger, which is essentially a long pole about 1 metre long with a T-handle and a screw-like head at the bottom which collects and retains sediment. Dutch augers are particularly useful for hard and wet sediments so worked very well through our silty clay colluvium. After taking a number of cores (with the excellent help of our two Young Archaeologists Club competition winners!) we eventually came up with some lovely layers of charcoal and burnt material, so we set to work digging three more test pits. Two of these test pits were more much more successful, particularly Test Pit 75 which showed a charcoal layer almost 30cm thick (see Figure 1 below).

Figure 1

Figure 1. SE-facing section of TP75 showing three very distinct layers: Top soil, colluvium and a ~30 cm thick charcoal and stone rich layer.

 Test Pits in the wider landscape

As well as ground-truthing the results of the geophysical survey, we have also been collecting samples for geoarchaeological analysis from some larger test pits dug by our new friend, The Big Digger. For those unfamiliar, geoarchaeology is an approach to archaeology which utilises techniques from the earth and environmental sciences to answer archaeological questions. In real life it mostly involves getting really, really muddy and pondering sediment sequences for long periods of time…

The main aim was to take samples from the colluvium in the wider landscape (identified during coring by Dr. Richard Tipping and Coring Supervisor Anna) for radiocarbon and pOSL (portable Optically Stimulated Luminescence) dating and micromorphology (the study of in-situ soils and sediments in thin section) to provide us with a proxy for human activity in the immediate area (see Figure 2 below). Colluvium results from human activity, particularly agriculture, and therefore can tell us about past agricultural processes in the wider landscape as it represents a period of soil erosion due to ploughing, over-grazing, and the removal of trees. Under gravity these sediments are then transported downslope. Sometimes, if geoarchaeologists are lucky, ancient soils will be preserved underneath the colluvium allowing us to infer a period of stability and identify the environmental conditions before the land was cleared. The nature of the colluviation also gives information about what processes caused it to erode, and how high the energy of its erosion was.

Figure 2

Figure 2. Students Oda and Daniel taking OSL samples in the extended section of T6 with Anna and Becky, and Director Paul also working hard in the background. Samples for pOSL were taken vertically down the sequence from the section by inserting tubes into the face of the section, removing gently and quickly securing with tape to ensure no light entered the samples. They were then labelled with a sample number and an arrow indicating the end that had not been exposed to light, ready for laboratory analysis.

Figure 2. Students Oda and Daniel taking OSL samples in the extended section of T6 with Anna and Becky, and Director Paul also working hard in the background. Samples for pOSL were taken vertically down the sequence from the section by inserting tubes into the face of the section, removing gently and quickly securing with tape to ensure no light entered the samples. They were then labelled with a sample number and an arrow indicating the end that had not been exposed to light, ready for laboratory analysis.

pOSL will hopefully allow us to identify the rates of erosion in the area, with the radiocarbon dates from the peat below effectively acting as an ‘anchor’ to identify when this erosion (and therefore agricultural clearance) began. Once the thin sections are made, micromorphology will allow us to identify the depositional and post-depositional processes occurring at the microscale.

Young Archaeologist Club winners visit the Kaims

y

Excavating the burnt mound in trench 6

The Bamburgh Research Project was happy to host the winners of the Young Archaeologists Club at our Bradford Kaims Wetland Site this last Saturday. The winners were William Allis, Elizabeth Allis, Kitty Underwood, and Rosie Underwood. We had a blast showing them around the Kaims and teaching them about prehistory and burnt mounds. We can’t wait to have more visitors from YAC next year!

yyy

Trench 6 supervisor Tom Gardner with the YAC winners

Elizabeth Allis (11 years old), wrote about her day at the Kaims:

“My brother and I had a great time digging at Bradford Kaims with the team of archaeologists. I really liked the long wooden platform that had been discovered, especially as it is the only one in the country! There was a strange wooden object near the middle of the platform, it had a sort of handle and three holes in one end. No-one knows what it is yet, I think it’s something that prehistoric people made and buried to confuse archaeologists later on. We did some troweling in trench six with Tom and found some charcoal, we put it in sample bags and labelled them. Cole showed us some of the finds like flint arrowheads and a prehistoric giant cow tooth. It was called an auroch. We were given t-shirts with an auroch skeleton on. I learnt a lot and the day was really fun. Thank you YAC, Paul and the rest of the BRP team.”

yy

Introduction to trench 6.

yyyy

Making simple rope from the sedges that grow near the site.

HLF Logo

english_heritage_logo1

Bamburgh and the YAC

Once again, on the 27th July, the Bamburgh Research Project will host three of the winners of the Young Archaeologists’ Club, ‘Dig It’, competition. The compition is open to all members of the YAC. Information about the YAC, and much more, can be found on the website of the Council for Bristish Archaeology (www.archaeologyuk.org).

Field School 2013

Don’t forget there are still spaces available for the field school with us in Bamburgh this summer.

Survey techniques

Survey techniques

We will teach you excavation methods, site recording, artefact processing and much more.

Nat and Liam in the flot tank

Nat and Liam in the flot tank

Camping accommodation is provided along with your tuition, which is great value at £235. We stay in nearby Belford, where there are all the mod-cons (Like a Co-Op, Pubs, Takeaways and stores!) and we have a great social life onsite too.

For more information, go to http://www.bamburghresearchproject.co.uk/
or join us on Facebook or twitter (@brparchaeology)

Young Archaeologist’s Club meets the BRP

This Saturday, the 21st of July, the team here at the Bamburgh Research Project had a visit from the three winners of the ‘Dig at Bamburgh Castle’ competition in Young Archaeologist Magazine. So first off, the BRP would like to congratulate Clare, Eleanor and Lucy for their winning entries to the competition. As blog followers will know, sunshine and warmth have been sorely missed at Bamburgh this year, and we were happy that Clare, Eleanor and Lucy brought some beautiful weather with them.

We started the day with a trench tour led by director Graeme Young.

Image

The girls learn about the enigmatic Trench 1.

From there we went up to the windmill, and investigated some of the ‘shiny finds’. Oh, and we gave away some prizes!

Image

Clare, Lucy and Eleanor each received a BRP hat, an “I Dug at Bamburgh Castle” shirt, Bamburgh Castle: The Archaeology of the Fortress of Bamburgh by Graeme Young, Bamburgh: part of the Archaeology in Northumberland Discovery Series, and a trowel to take home.

Image

Finds Supervisor Kirstie shows the girls an Egyptian bead from the shiny finds box.

And then we got down to some digging. I’d like to say that the conditions were right for small finds, that the girls got lucky, or that we saved a particularly nice context for them to excavate (#3241 for those playing at home) but the sad fact of the matter is that Clare, Lucy and Eleanor were just better than us. Period.

Image

(From Left) Lucy, Clare and Eleanor excavating context 3241. Or, Lucy, Clare and Eleanor showing up the archaeologists.

Finds included a piece of worked bone, a styca, copper fragments, a brooch pin and rolled lead.

Clare and her styca

Eleanor with her iron brooch pin.

 

Clare and Eleanor with the rolled lead.

Lucy shows a piece of worked bone.

As you can see, the Young Archaeologists tried their hardest to put our Grown-Up Archaeologists to shame. They excavated an array of beautiful small and shiny finds, and seemed to have a great day doing it. The Bamburgh Research Project had a great day with the girls, and we look forward to continuing the competition in the future.

If you or someone you know is interested in joining the Young Archaeologists Club, visit their website at http://www.yac-uk.org

And as usual, please dont hesitate to contact us on twitter @brparchaeology