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