Tuesday, 24 January 2012

WUN Researcher Mobility award

Feeling quite excited today as I have just finalised my travel arrangements to Seattle, where I will be a visiting fellow at the University of Washington, Department of Anthropology  in March and April, as part of WUN (Worldwide University Network) scheme. I'll be doing a whole bunch of things while I am there, including developing my research on Palaeoindian coprolites, and teaching seminars in bioarchaeology and geoarchaeology.

I am also really looking forward to visiting the Burke Museum of Natural History and Culture and meeting Julie Stein. I remember when I was an undergraduate being inspired her research on shell middens. Shell middens are the reason I became an archaeologist - as an undergraduate I read geography, and was always interested in Quaternary environmental change, and the relationships between humans and their environment. I ended up working on a shell midden site in Fiji for my dissertation, and discovered that the socio-cultural side of the past was equally as exciting as the environmental aspects. In fact the two are often linked, and it is this interplay that I try and address in my own research. The midden theme also continued, though now the majority of work has been on mixed ashy/organic middens, I do hope to get back to the shell middens at some point.

Spending time at UW will also be a great chance to get lots of microscope work done.  For the past few months I've been very busy with residue extractions for feeding Stonehenge and haven't had the chance to do any microscope work. I have a whole load of slides from Paisley Caves, Catalhoyuk, Bonucklu, Kamiltepe (the list goes on), just waiting to reveal their secrets...

Thursday, 19 January 2012

Today my desk is covered in....

Sometimes I have a moment where I realise just how odd my day to day work probably appears to non-archaeologists. And probably even amongst archaeologists some of the things I end up with on my desk are quite odd. I seem to have aquired a sort of reputation as a coprolite person, and have aquired quite the collection of material from all over the place. I didn't set out intending to be a coprolite person, it just happened as I couldn't really ignore them. During my PhD, which initially focused on formation processes of middens at Catalhoyuk, I came to realise that the middens contained quite a large quantity of coprolites, and if I wanted to understand what people were dumping (lol) into middens, I had to investigate what people were doing with this particular type of waste. For those of you not in the know, coprolite is a catch all term for ancient faecal material (though technically there are different terms depending on whether it is an actual fossilised bit of poo versus amorphous organic material or animal dung etc).

So as well as looking at ancient rubbish heaps, I also study ancient faeces. How odd you might think. But also, very useful! Coprolites are direct indicators of what people (or animals) were eating at a specific moment in time, and can give information on all sorts of useful things such as health, diet, lifestyle, animal foddering, perceptions of clean/dirty in the past. We can look at a whole range of material preserved within coprolites - seeds, bones, plant fragments. We can also use biomolecular methods - the same idea as extracting food residues from pottery - to extract information on species and diet.

So today my desk is covered in this stuff, as I was sorting out samples for Dr Piers Mitchell (Cambridge), who came to give a seminar as part of the new Palaeo lunchtime seminar series at York. Piers is a medical doctor who also has research interests in human health in the past amongst other things, and will be using a range of methods to see if there is evidence of parasites in any of my samples. Exciting stuff!

Saturday, 14 January 2012

Feeding Stonehenge - food residues in Neolithic pots

Lab day today, finishing off the last batch (for now) of pottery samples from Durrington Walls. Bit of background - my main research project at the moment is to investigate patterns of food consumption at Durrington Walls, the Neolithic settlement associated with Stonehenge. This involves selecting pottery from different parts of the site, extracting food remains, and seeing if there are differences across the site. Fatty food residues survive suprisingly well in prehistoric pottery (well, some of it, depending on the preservation conditions and other factors). They can be extracted quite easily in the lab by grinding up a small portion of the pottery and shaking it with solvent. The fatty residues dissolve into the solvent, and can then be identified by injecting the solvent into a GC/MS. In basic terms, the GC/MS seperates out all of the different parts of the food residue so we can identify the different components, and the result is something like this. Each of the peaks is a different lipid. Except the ones labelled with P - those are plastic contamination from the bags that the pottery was stored in after excavation. Pesky plasticisers leach into everything.

I've managed to perfect the extraction process so I can do the basic level of analysis on 3 batches of samples in 3 days, assuming nothing goes wrong in the lab, like running out of furnaced glassware (we put all of the sample tubes and whatnot in the furnace before using them, to get rid of any potential contamination from modern residues).

I quite like being in the lab on weekends. No one else is here so I have loads of bench space and can use all the kit without any hanging around. Soon all the lab work will be finished and I can really get going on the most exciting part - data analysis and interpretation. We already have some preliminary ideas of what might be going on from looking through the data we have so far, I'm excited to see what the results are like after all the statistics and GIS analysis! I just wish it wasn't so cold today (colder than it was over Xmas I'm pretty sure). I keep popping back to the office as the lab is freezing.

Monday, 9 January 2012

New micromorphology slides from Catalhoyuk and Boncuklu

I just recieved a nice suprise in the post today - a new set of micromorphology slides from the 2009 field season at Catalhoyuk and 2010 season at Boncuklu. I have technically been working on material from Catalhoyuk since 2003, when I analysed midden samples at the University of Reading for my MSc thesis, though I didn't visit the site myself until 2004 when I started my PhD. I've been working on the site ever since, in collaboration with Dr Wendy Matthews (micromorphology) and Dr Ian Bull (coprolites). It really is a fantastic case study for the type of high resolution approach that I am interested in. As you can see from the following pictures, the level of preservation (particularly in the lower, deeply buried deposits) is phenomenal, and enables reconstruction of past human acitivites to the extent that we can recognise individual actions such as the dumping of a fine layer of ash.

More recently I have become involved in work at Boncuklu, which is being led by Professor Baird at the University of Liverpool. As a possible predeccessor to Catalhoyuk, it it a great contrasting case study for questions of human activity and development, but also methodologically. The deposits excavated so far are much shallower, and so are likely to be more affected by bioturbation and weathering.

The photos below show a thin section of midden sediments from the South Area at Catalhoyuk. I have already published on midden material from earlier contexts at the site - these new slides provide an exciting contrast from later levels, and also have a very detailed associated sequence of houses that can be linked directly to the middens. This gives a unique opportunity to compare what was going on in a specific house with the midden directly adjacent to it, and to test some of the hypothesis proposed by excavators in the field.

The slides were prepared by Julie Boreham at earthslides.com, who is highly recommended. I would also recommend having a look at her 'virtual lab' Off The Bench, which has some great discussions on the practicalities of producing thin section slides. I can't wait to get these under a microscope, but it will have to wait for a short while as the next few weeks are very hectic in the BioArCh lab - another 60 samples of pottery from Durrington Walls arrived just before Xmas, to process for GC/MS and GC-c-irMS. That's analysis of food residues in pottery for non-chemists!

Sunday, 8 January 2012

6th Experimental Archaeology Conference

I'm having a rest today after 2 hectic days of co-organising the 6th Experimental Archaeology Conference with colleagues at the University of York. Funny actually that I just wrote that, when what I am actually doing is marking student essays on the development of cities and social inequality. But it involves sprawling on the sofa with the laptop on my knee, so is sort of having a rest, compared to the past two days of session chairing. The conference went really well, with only 1 or 2 small last minute hiccups, and led to some useful discussions and ideas for future papers and whatnot. I find myself thinking more and more about subject areas that I always thought I wasn't interested in, or were not relevent to me, as a 'scientist'. In particular the philosophy of science and archaeological theory, and the nature of archaeological data.

One paper at the conference also got me thinking about the way that people teach and learn archaeology, and how this then has impacts on how those people, as future researchers, carry out archaeological research. 'Experimental Archaeology' is a really good case study of this. Archaeologists may have  never been taught what an experiment is, or how to design an experiment according to scientific method, or the nature of scientific data and how to draw conclusions that are supported by the data (and the way that data has been aquired). All these things that are second nature to someone with scientific training,  appear to be absent from the teaching of archaeology, and it is really hard to explain to someone why they need to control (or at least acknowledge) more variables when they don't know what the definition of an experiment is.

This is not to say that archaeology is all about science and the opinions of anyone without scientific training are less valid. We can only go so far producing scientific data - we still need theory for that data to be interpreted and have any meaning. But when science is done, it should be done properly, and any researcher should understand the nature of the data they have produced (and therefore what can and can not be supported on the basis of that data). I remember as an undergraduate I loathed being forced to take a core Philosophy of Science module, but I am so glad that I did. It really does make you think about the process of doing science, and being reflective is always a good thing.