Micrograph of the Month - Waterlogged Wood

Here are two examples of waterlogged wood, in deposits from Medieval Riga, currently being analysed as part of the Ecology of Crusading project. It's been almost a year since I started on these slides, which were prepared in December last year - there are so many of them it is taking me quite a while to get through. It's a fascinating set of samples, such a mix of materials with some interesting post-depostional processes going on. In the upper image you can see a fragment of wood preserved entirely through waterlogging, within a mixed deposit containing charred material. This little fragment of wood has been stained orange, which is typical of waterlogging and mineralisation. In the lower image you can see a fragment of wood which has been preserved through a mix of partial burning (as seen by the black colour in the lower part of the wood), whilst the non-charred part has been preserved through waterlogging. Waterlogged deposits are relatively rare - most plant material in the archaeological record is preserved by charring. It will be interesting to see what other types of materials have been preserved in these conditions, as we work through the slides. Hopefully it will provide insights into the use of plant resources as well as the activities that were occurring in this part of the medieval city.