Saturday, 26 July 2014

Integrating archaeological science at medieval Riga

Team palynology and zooarchaeology
Team archaeobotany and geoarchaeology
Lovely weather here in London today, though mostly being experienced inside a meeting room at the Warburg Institute! I'm away from Edinburgh this week, firstly for a project meeting for the Ecology of Crusading project and then for a week of lab work in Bristol - more on that to come! This weekend I am here with fellow team members Rowena Banerjea, Alex Brown, Monica Badura and PI Aleks Pluskowski, discussing our  analyses of deposits from medieval Riga. This is the first time we've all got together to integrate our data, and to get updates on the dating of the deposits. So far  we have potentially the earliest known building in Riga, on the basis of dendrochronological dates, and some great archaeobotanical data on the types of plant materials that were being used - along with the micromorphology it looks like a lot of the plant material is associated with construction, such as wood chipping on floors. There's also some great data from a large (communal?) latrine which is giving us great insights into early health and diet (see also this recently published paper on the intestinal parasites from the latrine!). The geochemical data is showing quite distinctive differences between buildings, and even within buildings, in terms of the types of activities going on, though we are still trying to work out how this varies over the lifetime of the buildings.

Friday, 4 July 2014

Micrograph of the Month: Char and Charcoal

Getting ready for upcoming fieldwork at the Ness of Brodgar by going over the micromorphology slides I collected last year from middens. Analysis of these is still ongoing, but here is a peek at some of the things we can see so far. The image below shows two different types of material, char and charcoal. On the left are the images in PPL, on the right, XPL. Charcoal can be seen in the lower left image, and obviously is the remains of burnt wood, we can see the cell structure quite clearly. On the upper left however is something that initially looks like charcoal, but on closer examination is a little different, tentatively interpreted as char. Char is a term given to burnt debris from other organic material. I haven't see this in any other slides I've analysed, but it has come up in a couple of references, where it is suggested to be the result of fat burning. At first I thought perhaps the charcoal could just be highly broken up and degraded, but it looks as if the charred material actually surrounds individual sand grains (highlighted with red arrows), which supports the burnt fat hypothesis. This would fit with what we know about the consumption of animals at the site, as animal fat residues have been found in pottery. These 'char' deposits are found throughout this slide, and perhaps relate to the discard of BBQ waste :)