Friday, 9 August 2013

Investigations at the Ness of Brodgar Days 2 and 3


Planning sampling strategy with Jo

After planning the sampling strategy, the next few days have been spent collecting samples. I decided to focus on two areas of nicely stratified midden for the main sampling, and have collected overlapping sample blocks to provide an overview of the entire sequence. Already it's possible to see some quite ashy areas, so hopefully we will be able to get some nice information on resource use, and hopefully what activities the fuels relate to. We decided on a further 4 areas as secondary sample sets with a smaller number of samples, testing specific hypotheses from the excavations. More on those later this week.

As well as the Orkney students, we also have a team here from Willamette University, Oregon, led by Professor Scott Pike. Professor Pike has a background in geology and expertise in pXRF (portable X-ray fluorescence). In brief this involves using a piece of kit that looks like a ray gun to fire X rays at material, which then reflects the energy back. Different elements reflect the energy in different ways, and can be identified on this basis. His team have been conducting analysis of floor deposits to identify activity areas from chemical signals, which fits in really well with our micromorphology.  Certain elements are associated with human activity, for example phosphorus, and by mapping the concentrations across the floors we can get a good idea of the intensity of activity in different parts of a building. Yesterday Scott and his students took readings from the 2 main sequences of midden deposits I have sampled, with the aim of providing a complementary set of geochemical data that can be linked to the micromorphology observations. This way we can provide both a visual and chemical characterisation of the deposits, and hopefully a more secure interpretation of the formation processes and activities that are represented.

Sample block ready for removal
It's been great working here over the past few days. Perhaps not suprisingly, there have been quite a few familiar faces at the site, and it's been great to catch up with a few people. Professor Mark Edmonds from the University of York is here helping out with excavations and providing his expertise on the lithics (some amazing stuff coming out whilst I've been here, again check out the site blog!), and Dr Ben Chan, who I worked with on the Feeding Stonehenge project, is also here running one of the excavation trenches. I also got to meet a few people who I've only ever spoken to by email, including Dr Roy Towers, the pottery specialist who sent me the samples for the pottery residue pilot study I did last year at York, as a side project to the Feeding Stonehenge analysis. I just wish I was able to spend more time on site this year - one of the great things about fieldwork is getting the chance to spend time with like minded folk who share your excitement about ancient rubbish heaps.

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