“It’s just a thin wafer…” Technical Skills Workshop Review: Thin Section Preparation with Sydney Analytical

AAIA Volunteer, Stephen Croft, recently previewed an upcoming skills workshop run by Sydney Analytical.

For archaeologists, ceramics provide a wealth of information. Practically indestructible fragments of ancient pottery and terracotta can reveal the technical capacities and social practices of past peoples through petrographical analyses. This involves taking extremely thin sections of the material, a challenging, but vital skill.

As someone fascinated by efforts to provenance ceramics from the ancient world, I was thrilled to be able to attend a workshop on thin section preparation at Sydney Analytical. This was the trial run for what promises to be an enjoyable and informative introduction to the principles and uses of thin section making.

Though we began the day with an overview of the theory behind thin section preparation, this was very much a hands-on workshop, and I was soon enough putting on a lab coat and watching the first demonstration. If a saw could be described as approachable, that is certainly how I would introduce what our instructors used to transform a piece of granite into small rectangular billets. While we were not able to use this saw, even someone with a dubious relationship to power tools should have little to worry about using any of the other equipment throughout the course of the workshop.

Since waiting for the billets to be glued onto glass slides would have taken too long, like on any good cooking show, we were given some that had been prepared earlier. For the archaeologist in me, the choice between granite or terracotta was simple, as I was eager to prepare my first ever pottery section. The section was of modern terracotta, so I promise no ancient sherds were harmed! As it turned out, though, I got an opportunity to work on a section of the granite as well.

My prepared thin section of modern terracotta

Preparing the sections began by by trimming the excess off our slides, leaving a thin enough sample that it could be sanded down. The ‘thin’ in thin section is no understatement: we were removing microns at a time. Some of this sanding was done over lunch, when our slides were left to sit on a lapping machine, however the process was finished manually. Checking my sections against the micrometer, I found that the modern terracotta, though easier to sand down, was more refined and so is not as spectacular under the microscope as the granite. Even so, it felt rewarding, at the end of the day, to take both sections home, knowing that they were my own.

My prepared thin section of granite

After one workshop, I am still far from an expert on thin section preparation, or petrographic analysis for that matter. Yet, what was once a field I had only read about, is now one that is tangible, and one to which, after further study, I hope to be able to contribute.

I would encourage anyone interested in petographic analyses to attend the upcoming workshops. The trial I attended was for the Beginners I workshop, but a Beginners II has also been added to the schedule (see the flyers below) and in this you would be able refine the skills learnt in the first workshop and bring in and prepare a material of your choosing! These will be running soon:

Beginners I on 21 April and 7 May and;

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Beginners II on 3 May and 14 May.

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I would like very much to thank Sydney Analytical and the workshop presenters, Sarah Kelloway and David Mitchell. I hope everyone who attends an upcoming workshop enjoys it as much as I did.

Stephen Croft is an undergraduate at the University of Sydney, studying a Bachelor of Arts, majoring in archaeology, and a Bachelor of Laws. His research centres on the Late Bronze and Early Iron Ages of Greece and Italy, with a particular focus on Mycenaean interactions in the Western Mediterranean. Stephen is a team leader with the Zagora Archaeological Project, working with Stavros Paspalas on the examination of the history of the sanctuary area of Zagora.

Contacts

Dr Stavros Paspalas – Director
Australian Archaeological Institute at Athens, Room 480, Madsen Building (F09), University of Sydney NSW 2006 Australia
+61 2 9351 4759 +61 (0)2 9351 7693 arts.aaia@sydney.edu.au