Wednesday, 11 July 2012

Day of Archaeology - What happened next?

A couple of weeks ago I wrote a blog post as part of the Day of Archaeology which aims to give people an insight into the variety of work that archaeoklogists around the world do. There are some really fascinating stories on there, and it was great to see a few posts from fellow Çatalhöyük types (faunal team and human remains team) on what they are up to this year. This is the first season in a long time that I won't be heading out this summer. We are just too busy finishing off all the lab work for Feeding Stonehenge. My post outlined a typical day in the bioarchaeology lab at the University of York, featuring more of those poetry inspiring pot sherds from Durrington Walls. This is just a little follow on to explain what happened next....

So, we got to the point of putting the extracted samples on the GC/MS which works something like this:

Step 4 actually involves a lot of manual checking of the data to make sure what the computer thinks the lipids are is correct - it can only compare the archaeological material to what it has in the reference database, so sometimes we need to work out the structures of the lipids ourselves (remember doing mass spectrometry at school? If only everything was as simple as ethanol!). There's actually a bit of a queue at the moment as we have lots of students doing pottery residue analysis, working on samples from all over the world, including early North American pottery, Jomon pottery, Mediterranean pottery, Neolithic Scottish pottery..... So far the samples from Durrington Walls appear to be dominated almost completely by animal fats, however there are some very interesting differences in the types of animal products, and their location on the site. But I can't give away any secrets yet, we still have the final lot of samples to run for compound specific isotopes (to distinguish between adipose fats and milk) before we come to any conclusions!