Today was another whirlwind adventure in Archaeological Soil Micromorphology. The morning was spent listening to a lecture on the evidence for non-intensive cultivation and the afternoon built on this with a discussion of the evidence for slightly more intensive agricultural practices, particularly heavy manuring, burning, and ploughing. The topics are fascinating but the microscopic evidence in thin sections is extremely complex.
In attempt to ease the complexity added by time and post-depositional forces we discussed numerous experimental examples first, specifically the Butser farm site and the Umeå site (see Goldberg and Macphail 2006). The Butser farm experiment is a reconstruction of an Iron Age village that was thoroughly tested for many things before, during, and after occupation. The researchers also burned some of the dwellings and studied the resultant impacts on the subsurface. The Umeå site is similar but specifically tested the impact of slash and burn agriculture and ploughing (plus some other things). These examples are invaluable. The reason being that all the evidence for human modification to the landscape during occupation is masked by everything that has happened since abandonment; the pesky post-depositional process like pedogenesis, bioturbation, erosion, re-occupation, etc, etc. Therefore, these experimental projects were the first step, allowing us to understand the immediate impacts before moving into numerous examples of manured, burned, ploughed, and trampled soils and sediments that have been buried for a couple thousand years. It all makes sense when you think about it but the tough part is recreating the history of a sediment or soil after I identify numerous features in the thin sections.
Yes, that’s right, the features I can now identify. By no means am I an expert or even an intermediate. I am still 100% a beginner, well maybe 99%. Nevertheless, I feel as though this Wednesday was the day when I overcame some imaginary hurdle (perhaps a hump) toward proficiency in soil micromorphology. I am able to compartmentalize the sample into the coarse and fine fraction, identify the primary mineral components like quartz, glauconite, feldspar, mica, etc., say something about the structure (the porosity, the sorting, the shape, and abundance, etc.). I learned how to identified shell, egg shell, bone, phytoliths, calcium oxalate spherulites, phosphate enriched soils, charcoal, and organic matter. I also saw a fungal spore but didn’t locate it myself, although I feel I could now.
Most of this learning is thanks to my great classmates. There are about 12 of us (give or take a couple) and today everyone opened up a bit, the atmosphere was a little more collegiate and it made a huge difference. Maybe it was the group outing to the pub yesterday….either way, everyone had something to offer, except for me now that i think about…let’s say I added the enthusiasm. We even had a short presentation on phytolith morphology. I now know what a banana phytolith looks like and know way more about the domestication of bananas than I ever imagined I would. Sorry, that isn’t true. I’ve never even thought of banana domestication until today. It has a very interesting and complex history goes back to Papua New Guinea about 6000 years ago. I don’t have a reference but this seems to line up generally with what was said today if you want some more general information.
Personally, I stuck to my same strategy as yesterday: pairing slides with their publications and reviewing basic identification concepts and locating the appropriate feature or component in a number of slides. I am almost finished with the major concepts so tomorrow afternoon I move onto systematic thin section description from start to finish. By tomorrow night I will know whether I did actually make it over the hump or am still teetering somewhere near the top…let’s just hope I fall forward if it’s the latter.
I ended the day with a tall dark Guinness and walked home with a some fish and chips wrapped in newsprint. Mmmm!
Back tomorrow with another update.
Goldberg, P. and R. Macphail, 2006 Practical and Theoretical Geoarchaeology. Blackwell Publishing, Oxford.