The unexpected little joys of lithic use wear analyses II

A little while ago I posted a photo of a crystal inclusion in a white flint bladelet. I promised to post some more, whenever I think of it. So here is another example of the beautiful things I have encountered doing the use wear analyses. This burnt flint bladelet, like the last example from Late Mesolithic layers at Lutter/St. Joseph, France, did not show any signs of use. However, the microscope does show beautifully the microfossils within the flint, or possibly radiolarite, out of which it was made. And, like the last example, this photo also shows the possibilities of the digital microscope I have been able to use for the study of the use wear analyses of Late Mesolithic artefacts from two Lutter/St. Joseph, France and Arconciel/La Souche, Switzerland.

Micro-fossils in a Late Mesolithic burnt retouched bladelet from Lutter/St. Joseph, France. Composite (focus stacking) image (150x) I made with a Keyence Digital microscope (Dep. Of Geosciences at the Université du Fribourg, Switzerland.)

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The unexpected little joys of lithic use wear analyses I

Sometimes, when doing the microscopic analyses of use wear traces I come across fascinating things that have little to do with the actual use wear of the tools being studied. Instead they either provide something of a background to their natural origins or are just visually interesting. The digital microscope I have been using at the Dep. Of Geosciences at the Université de Fribourg, Switzerland has many technical possibilities. It allows me to document not only the use wear traces using a variety of photographic technologies. It also provides the opportunity to record composite photos such as this one of an otherwise not very interesting bladelet fragment from the site of Lutter/St. Joseph, in the French Alsace. I’ll try to publish a few more of such examples in the near future.

Crystal inclusion in a Late Mesolithic flint bladelet fragment from Lutter/St. Joseph, France. Composite (focus stacking) image (100x) I made with a Keyence Digital microscope (Dep. Of Geosciences at the Université du Fribourg, Switzerland.)

The lab II: Is that a bit of dead sheepskin on your distal end?

After a short break, which I mainly spend writing the Hospental-Moos lithics report and flintknapping a bit, I am back at the microscope again. I now feel quite confident that I seem to have found my way around the machine and to have found, at least for now, my favourite settings. That is, the ones that seem best for my work. The photo shown here is a composite, The microscope takes a large number of photos, each with a different focus and combines them into a single picture with a large depth of field. This make it possible to produce the level of detail shown here.

The photo shows the distal, steeply retouched dorsal end of a scraper. That is lithic analyst speak for the scraper’s working edge, the bit that actually touches the material it is used to work. In this case that was dry sheepskin. And that is exactly what the white stuff atached to the stone is: sheepskin residue. At the Late Mesolithic site of Arconciel/La Souche (Switzerland) many very small scrapers were found and this scraper is pretty much an experimental replica of some of those scrapers.

Experimental hergestellter Kratzer aus Radiolarit. In der spätmesolithischen Fundstelle Arconciel/La Souche (Schweiz) wurden vielen solchen Kratzer gefunden. Bild gemacht mit einem Digitalmikroskop.
Experimental radiolarite scraper. At the Late Mesolithic site Arconciel/La Souche (Switzerland) many scrapers like this were found. Composite photo made with a digital microscope.

During its experimental life (More information and photos here), this radiolarite scraper was on of seven which we used hafted (in a wooden handle, using birchtar and sinue) or unhafted to scrape sheep- and goatskin. Now taken out of its haft and cleaned, it is part of the reference collection for my use wear project,