Castles and Coprolites

I'm in the middle of writing a brief introductory paper about the work we are doing at Paisley Caves, which includes some of the micromorphology results from our pilot study. The slides from this site are complex, and also so fascinating. Complex because the are very heterogeneous and include a huge variety of biogenic material, including lots of fragments of plant tissues, and there is also some weird stuff going on with the chemistry in the cave environment. Here is an example of a small fragment of wood, within a layer of mixed material overlying a layer of microfaunal dung pellets. The layer is between two radiocarbon dates approximately 8180 and 9565 years cal BP. In the picture below I've shown it at a range of magnifications, and images C and D show it in PPL (C) and XPL (D). Modern wood in XPL usually looks a bit fluorescent because cellulose is birefringent. Usually with archaeological material I'm much more accustomed to seeing wood in the form of charcoal! The on...

You know nothing, Lisa Shillito! This is how I sometimes feel being a micromorphologist, especially one looking at samples that are a different to the contexts I am used to. Here are some more images from the Lufton Roman Villa sample I mentioned last month . I am not actually going to say much about this as I am not entirely sure what it is, and basically am scouting for opinions from fellow geoarchaeologists. This is a small rounded inclusion about 1mm in length, consisting of lots of brownish purple rhombohedral crystals embedded in a yellowish (almost ash-like?) matrix. As you can see, the crystals themselves don't look much different in XPL. The inclusion is located within a layer of mixed microcharcoal and calcareous debris (probably from the lime layer underneath). There are some bits of lime that have a similar appearance, sort of like iron staining of the carbonate. My guess is possibly iron carbonate crystals replacing the calcium? I will definitely be bringing this slide...

I haven't posted a micrograph for ages, but this one is so pretty I just had to share it. I'm in the middle of doing an analysis of Roman occupation deposits for the Lufton Roman Villa project . I don't know too much about the wider context yet, but my initial observations of this particular sample suggests we are looking at an old floor surface. There are 3 distinct layers, and the uppermost layer is composed of a calcareous material, in which are embedded lots of tiny crushed up ceramic fragments. The middle layer is a sandy aggregate with the occasional bit of soil/clay and charcoal, and there is a very thin lowermost layer (thin because of the sample size, not sure yet how thick it was in the field) which has a lot of organic material including wood and grass charcoal, and possibly fungal spores. I will be writing more on this as the analysis progresses, but for now here is a nice image of one of the ceramic fragments (the orangey-red rectangular inclusion) embedded in...