Day 5………..

November 13, 2009

Today was the 5th and last day of the Training Week of the Archaeological Soil Micromorphology course I have been taking. It has been extremely tiresome and a bit stress inducing at times but extremely worthwhile.

As an aside, I realized that some of you may have no idea what a micromorphology thin section looks like. There is an incredible range of variation but one example can be found on the wesbite for the joint Turkish/American project at Üçagizli Cave, Turkey. If you scroll down the page you will see the sample still in the profile followed by the thin section after processing.

Back to today’s update:

The structure of today’s work was a perfect way to end the course. The morning was a lecture on the micromorphological signatures of medieval structures and how to identify workshop areas or other industrial processes. As per usual this was followed by a few hours perusing the relevant reference collection. This was the last major topic for the course, the afternoon session swung back full-circle and re-addressed the systematic nature of describing thin secctions and the necessity of proper data presentation. Rather than continue browsing slides following the reminder we were all given an hour to systematically describe a thin section of our choice, make some form of educated interpretation, then present it to the class. This was intimidating. Not only because 4 days ago I knew next to nothing about the topic but also because we were told it takes an experienced micromorphologist roughly a half day to fully examine, describe, document, and make an interpretation for one slide. Regardless, this was our excercise and we went ahead and put together our descriptions then presented them.

My slide was from a Saxon occupation and the description, the short version, went something like this:

Homogenous thin section with numerous inclusions. Weakly separated granular microstructure with unaccommodating peds, massive intrapedal microstructure. The ratio of course and fine fractions (c:f) is 2:3 and the c:f related distribution is single-spaced equal enaulic…(There is a bit about the coarse fraction mineral content, coarse organics, and the fine fraction in detail but I will spare it here)…Large plaster/mortar floor fragment in upper section, smaller rounded and iron stained mortar/plaster fragments in lower section, small accumulation of mm-sized iron slag fragments in middle portion, and frequent iron staining/mottling throughout section. This represents a mixed deposit with evidence of occupation floors, potentially redeposited and significant post-depositional movement of iron.

That is a quick overview of the description I did. A little simplistic but not too bad for my first time. I need to brush up on my abilities to identify minerals and rock types but I was happy. You’ll notice it contains a whole bunch of fancy speak, but it’s necessary to maintain consistency and comparability in the description of thin sections. All the terms above have strictly defined definitions that include quantitative estimations (see Stoops 2003). This type of stuff is for data tables and databases, not necessarily all of the nitty-gritty goes into the final publication, unless it is a monograph, report, or something similar.

And that’s that….except for the hours and hours I still need to spend looking at reference collections and analyzing my own thin sections. A great week! Now it is time to sleep.

References:

Stoops, G. 2003. Guidelines for Analysis and Description of Soil and Regolith Thin Sections. Soil Science Society  of America, Inc., Madison,Wisconsin.

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Parc Safari Update

November 12, 2009

Wanted to update you all on the Parc Safari work that has been going on. The students have written a number of great posts that overview some key aspects of this year’s work. Check it out here.


Day 4…Microscope Eyes

November 12, 2009

Today was much like the past few days. My approach to learning Soil Micromorphology has been working so I stuck with it. I did make one minor modification though. Rather than pair slides with their relevant publication and go over the identified characteristics, I pulled out one of the best guides to Archaeological Soil Micromorphology, Soil and Micromorphology in Archaeology by Courty et al. 1989, and went through the major concepts while trying to locate evidence for each one in a number of slides. It was a bit frustrating but overall it went well. Not really the best approach unless you have slides that have already been analyzed and are supposed to have these features but it worked for me today and I recommend it.

The best part of this course is the enormous reference collection of thin sections that is at our disposal. After each topic is introduced, remember the two lectures a day program followed by hours of examining slides, we are introduced to another set of thin sections relevant to the topic. That means every half of day the slides we can look at grows and grows. Now that I am feeling a bit more confident in my approach to soil micromorphology I have realized just how valuable this experience truly is. The only unfortunate part is I wish I had more time to look through all of these things and really thoroughly study each topic in detail. A week doesn’t really lend itself to that however.

Today we were introduced to two more topics. We shifted into more rural habitation and looked at occupation surfaces, such things as constructed living floors like plaster, mortar, daub. This was the morning. In the afternoon we were treated to a lecture on the vague term Dark Earth. This type of sediment dates to the post-Roman period and is related to urban deposits that have been the medium in which soil has formed. As per the name it is very dark and visually diagnostic, often producing an extremely homogenized deposit. I won’t go into to too much detail but take a look at Dr Richard Macphail’s work if you’re interested in learning more. It is an extremely ubiquitous sediment type in London in particular and is an amazing example of how soil micromorphology can be applied to archaeological questions.

In addition to all this my eyes have begun to revolt to excessive use of a microscope. It may have something to do with a lack of sleep but I don’t have that luxury for another day so I am going to pretend it doesn’t exist.

Back tomorrow with Day 5 update, the final day of the training week.


Day 3…Over the hump day

November 11, 2009

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.

References:

Goldberg, P. and R. Macphail, 2006   Practical and Theoretical Geoarchaeology. Blackwell Publishing, Oxford.


Day 2….the learning curve is now actually a curve

November 10, 2009

Day 2 of the Soil Micromorphology course is in the books and it was another long day looking through a microscope. The same general structure as yesterday.  The morning lecture covered Hunter-gatherer and low-impact activities on the landscape. The rest of the morning was spent looking at associated thins sections. The afternoon started with a lecture on the evidence for clearance activities and pastoralism in thin sections, again followed by many hours of browsing relevant thin sections from a large reference collection.

As with yesterday I think the lectures were great. It would be nice to have a bit more (or maybe more explicit) explanation of what characteristics identify the various features for the topic at hand. At the same time however, there is something extremely satisfying about figuring it out yourself afterward. In fact I took a very different approach to my time with the microscope today and it proved much more fruitful than yesterday. Rather than blindly looking at slide after slide wondering what I was supposed to be seeing, I re-read through one of my text books and for each concept I would ask the professor for an appropriate slide and then identify the features for that topic. For instance, I read through aeolian sediments and then identified the various components in a photomicrograph that distinguish it and variations on it, including secondary deposition and pedogenesis. I did this for numerous concepts. Next, I took slides for which there are publications with full descriptions and interpretations and went through a particular paper and its relevant slides together.

I didn’t look at as many slide today but I learned way more than yesterday. At the very least the learning curve now has a slight incline. The day was capped by a nice British stout at the pub. I couldn’t believe the pints were only 1.60 pounds, which is about half price of a pint in Canada after the exchange. Then I walked south to Charing Cross station through Trafalgar Square where I caught the train home for the night. I took a great picture of the square all lit up with the fountain on but unfortunately I forgot the cord to connect my camera. Guess you’ll have to wait a week for pictures.

Until tomorrow’s update,

Cheers


And it Begins….Ever so Slowly

November 9, 2009

Hello to everyone from sunny old England. I arrived in London this past Saturday, the overnight flight from Ottawa of course, only to be treated to a quirky British tradition surrounding Guy Fawkes day. In a small, yet enormous by London’s standards, back yard I spent the evening watching people set off fireworks and stare into a bonfire in honour of the parliament not being blown up back in the day. There’s a lot of information out there on this so I won’t dwell on it.

Sunday might as well not have existed thanks to jet lag but I did catch up on sleep. This was a good thing because today was the first day of my Archaeological Soil Micromorphology course at the Institute of Archaeology at UCL. The course is focused on a technique that involves collecting intact sediment samples, embedding them in resin, slicing and dicing, sticking them to a glass slide, and finally grinding them down to 0.03mm thick before sticking them under a microscope for description and interpretation (includes both geological and archaeological sediments). I have been looking forward to this course for months, reading as much as I could and looking at as many images of thin sections as possible. I thought I was somewhat prepared…boy was I way off.

The course started with an introductory seminar, followed by 3 hours looking at reference thin sections under the microscope. Lunch break was great! I found a nice sandwich and bag of crisps (aka chips) for 3 pounds. Then the afternoon was a lecture on buried soils and the numerous taphonomic factors that act upon them. This included marine water fluctuations and the resulting cycle of pyrite formation and oxidation, as well as other things like the velocity of deposition in flash floods and the sorting patterns produced. This lecture was again followed by a few hours of browsing reference samples under the microscope.

Today’s class was not overly uplifting. The lectures were great, the concepts all make sense and the interpretation that follow are somewhat satisfying. Even the basic principles of deposition, soil formation, and post-depositional alterations all fit nicely into my head. My biggest stepping stone is understanding the identification process. How do I know which minerals are quartz, pyrite, tourmaline, muscovite, etc. from clay, shell, bone, flint, and ash fragments.  Coming from a purely archaeology side of things (specifically North American archaeology rooted in an Anthropology department) my optical mineralogy, and mineral crystallography are a little weak…if not non-existent. So, some pretty major hurdles and there was quite a bit of frustration today but at least I know what I need to learn. To me, that’s a pretty good first day. I already know what I need to get out of this 2-week course.

So after 6 hours with the microscope today and a couple more reading, the screen is starting to go a bit blurry. It’s time for me to stop and do some more reading on birefringence. I’ll be back tomorrow night with some updates on the course and my progress.

 

 


As Promised….Parc Safari Pet Cemetery

October 27, 2009

As I left things hanging a bit in my last post I guess it is only fair to fill in the missing pieces before moving on to something else. This requires me to back track a bit first….

In September of 2007 I moved my life to Montreal to start graduate school. On my very first day, literally the morning after I moved into my tiny apartment, I strolled into campus to meet my MA supervisor, the same individual that is now one of my PhD co-supervisors. I barely made it through the door of his office before he asks me to take a look at this amazing e-mail he just received. It was from the director of zoology at Parc Safari, an African animal park south of Montreal in Hemmingford, Quebec. The park had decided they needed an educational display in their entrance building and the perfect complement would be some articulated skeletons of African wildlife. Logically this meant they should contact the McGill archaeology department and ask them to dig up the park’s cemetery and then articulate the skeletons they found, particularly hoping for an elephant or rhinoceros. This is exactly what was in the e-mail my new supervisor read to me, only to follow it with his plan to turn it into an undergraduate field methods and zooarchaeology course. All this before I even got a chance to introduce myself. Regardless, I was sold and so began the first year, we’re now in the third year, of the Parc Safari field methods class.

If you want to get caught up to date on the past two seasons you should swing by the McGiil Zooarchaeological Field School blog that is put together by the students each year. This year’s group is ironing out some details and will be posting updates really soon, so keep an eye on it. As a taste I will tell you that last Friday we mapped and removed approximately 75% of a large male watusi. We know it is large and male because we excavated and re-articulated a complete female watusi during the first season.

Parc Safari 2009

Don't be fooled by the scenery...under this surface lies a cemetery for African wildlife

Although it may sound like just fun and games there is in fact a lot research going on at the site in addition to those fun and games. We are looking at the taphonomic impact of decomposing cadavers, vegetation reflectance signatures that can help in the identification of clandestine mass graves, 3-dimensional reconstructions of excavation pits, and more. Don’t take my word for it though, go see what the students think about it all.


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