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What is Thin Sectioning?

Thin-sectioning (also known as, thin-section analysis) is an important technique used in Archaeology for the examination of the composition of various materials. Typically, such materials include ceramics or stone.

Thin-sectioning is the removal of a very thin piece (roughly 0.03 mm) of material from the object in order to be observed under a microscope. The sample needs to be so thin that the details of the material (small internal structures, and crystals) are readily displayed in the microscope in order to undergo proper analysis. This method is crucial in determining the raw material used for the specific object, or in the case of faunal remains, determining how the animal was killed. While we are able to obtain crucial information from thin-sectioning, it has some limitations. For instance, thin-sectioning is an abrasive method which doesn’t align with the archaeological view of limiting destructive analysis techniques on artifacts.

 

Thin sectioning is only done on samples with no accompanying context. Here samples are first coated with epoxy to create pucks that are later cut to a thickness of 30 microns.

 

Thin-sectioning is a core method in petrology, or petrographic analysis, which is the identification of mineral composition and texture of the material, such as rocks and ceramics. Such technique is not limited solely to ceramics or stone, but applied to soil, plant, or bone remains. Petrographic analysis can be used in many diverse areas of study. For example, Gregory V. Braun from the Department of Anthropology in the University of Toronto, used petrography to investigate Iroquoian ceramic production and smoking rituals in a middle Ontario Iroquoian village near southern Ontario. For those interested, the link to his publication is in the reference section below.

 

Thin-section samples from Sustainable Archaeology: McMaster in varying states of progression.

Both images are sourced from Sustainable Archaeology: McMaster. July 29th, 2015. http://www.dayofarchaeology.com/sustainable-archaeology-mcmaster/

References

Biittner, Katie M. and Susan M. Jamieson. Chert Raw Material Utilization at the Bark Site (BbGp-12), Peterborough County, Southern Ontario (2006). Ontario Archaeology 81/82.

Braun, Gregory V. Petrography as a technique for investigating Iroquoian ceramic production and smoking rituals (2002). Journal of Archaeological Science 39, 1-10.

Day of Archaeology. “Sustainable Archaeology McMaster: A Day in the Life of an Archaeological Repository.” Published July 29th, 2015. http://www.dayofarchaeology.com/sustainable-archaeology-mcmaster/

Archaeology Wordsmith. “Thin-Sectioning.”Accessed April 4th, 2018. http://www.dayofarchaeology.com/sustainable-archaeology-mcmaster/

ROM Collections and Research. “Ceramic Petrology Laboratory.” Accessed April 4th, 2018. https://www.rom.on.ca/en/collections-research/research/world-culture/ceramic-petrology-facility

A Look Back: An Unusual Holcombe Point in the Vogt Collection

Originally from the Palisade Post, 1987 Vol 9 no.1

The museum received a donation of artifacts from the Vogt family, obtained from Lambton County. One of the artifacts in this collection is an unusual “Holcombe” point.

Drawing made for the museum by artist Catherine Comrie.

The Holcombe point type was first defined on the basis of specimens recovered on Holcombe Beach in Macomb County Michigan. Often made from Onondaga or Bayport Chert, this lanceolate point with a concave base and fine parallel flaking is confined to the later part of the Paleo Period ca.8000 BCE.

Holcombe points are always quite thin, have lateral edge grinding, and are rarely fluted. Although rare in Southern Ontario, at least one site with predominantly Holcombe points has been documented in the area.

This point classified as Holcombe is made from Flint Ridge Chert, which outcrops in Ohio. According to knowledgeable researchers, very few Holcombe points are made of this material.

At first glance, this point appears to be uni-facially fluted (ie. similar to fluted points). Close examination reveals that a large flake was removed during the preform stage, and that it is not a flute but rather a scar from a large flake removed from the tip. The concave base has been heavily retouched but is not ground.

Based on size alone, this point is much larger than typical Holcombe points measuring at 5.7cm in length. As with the specimens found at Holcombe beach, it is possible this point finished it’s life as a hafted knife.

A Look Back to the Lawson Site Pot

Reconstructed pottery front face.
Front face of the reconstructed Lawson Site pot.

During the 1982 excavations on the Lawson Site, museum archaeologists discovered on of the more interesting deposits of pottery fragments yet encountered on the site. The pot sherds were interesting not only because we have been able to reconstruct them into a very large pot but especially because of the location of the fragments and what they were found with.

The pottery fragments were in the bottom of a large pit found inside the largest house yet uncovered on the site. This pit was located under the south bench row near the east end of the house. In shape, the pit was a flat-bottomed cylinder. During excavation, it was first though that this feature was a deep basin-shaped pit, but it was discovered to have a false bottom like a previous feature uncovered.

Recosntruction of the large Lawson vessel
The pot takes shape, showing temporary supports.

The overall pit contents include ceramics, chipped lithics, a hammerstone, modified bone, bone fragments, and carbonized plant remains. There was a small pottery concentration in the upper portion of the pit, but the most productive part of the feature was the lower portion. The bottom of the pit was lined with many pottery fragments. The sherds had been purposefully placed around the edges and bottom of the pit in the same way that one would use the tile fragments to line the bottom of a flower pot.

Resting above the main sherd concentration were the articulated radius and ulna of a black bear showing cutting and chewing marks on the bone. Below the main pottery concentration was a complete upper carapace of a turtle, unfortunately warped from resting upside down on a fist sized rock.

The pot fragments found lining the bottom of the pit were glued together to form almost two thirds of the large pottery vessel depicted in the above photo. The rim of the pot had multiple castellation’s but was completely undecorated (Niagara collared type), a common style of pottery on the Lawson Site.

Update: New digital technology allows us to reconstruct these pottery pieces virtually as opposed to physically which promotes the conservation and longevity of the original artifacts.

Originally featured in Palisade Post 1988 Vol.8 no.3

by Dave Smith

 

Four Gift Ideas for an Archaeology Friend

Gift #1: Customized Trowel

Every archaeologist knows that when you have a trowel you must hang on to it, because you never know when it will get mixed up with someone else’s onsite. We often mark our trowels with a symbol or name to break the cycle of confusion, but alas, trowels still go missing. Developed as a hobby by an archaeologist for other archaeologists, Hermit Woodworking designs custom trowels that you can buy online or custom order with specific colours or inlays (Harry Potter theme anyone?!)

Image of trowels arranged in a crescent shape with multiple coloured handles made of wood
From Hermit Woodworking Facebook Page

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Processual Archaeology

Archaeologists working in the 1960s, such as Lewis Binford, developed the theory of New Archaeology, which tries to understand the forces that cause cultural change. New Archaeology is also known as Processual Archaeology.

Lewis Binford and archaeologists like him realized that archaeology had unused resources. These new archaeologists argued that they should look at the populations of today to understand more about the populations of the past.

For example, Binford conducted an ethnographic study among the Nunamiut of Alaska. He lived with, ate with, and learned about the Nunamiut to better understand how hunter-gatherers lived in ancient France. Binford observed the waste materials created by knapping stone for tools, and found similar waste materials in the archaeological record. By linking modern understandings with archaeology, Binford learned more about past technologies and learned why stone fragments appear the way they do in the archaeological record.

Archaeologists now answer questions by combining understandings of many disciplines. Before this change, archaeologists could only describe sites, or ask questions about what the artifact was and how old it was. To understand the ‘why’, archaeologists take an inter-disciplinary approach by working with people such as sociologists, chemists, biologists, and geophysicists, just to name a few. Sharing knowledge between these disciplines allows archaeologists to develop their understanding of material culture better than ever before.

Bibliography

Binford, L. (1972). An Archaeological Perspective. New York: Seminar Press.

Renfrew, C., & Bahn, P. (2008). Archaeology: Theories, Methods, and Practice (5 ed.). London: Thames & Hudson.

Willey, G., & Sabloff, J. (1974). A History of American Archaeology. London: Thames and Hudson.

Copper Manufacturing of the Archaic

By: Ira Lehtovaara

Out of the known materials that were made by the First Nations, the copper materials that have been unearthed over the years are indeed fascinating. But where did these materials originate? How were these objects created? And what were copper objects used for? When journeying through the archaeology of these copper materials, even professionals in modern blacksmithing and Indiana Jones himself can only marvel at the brilliant copper manufacturing skills of the First Nations.

Archaic copper axe, MOA Permanent Gallery

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International Archaeology Day: What You Need to Know

On October 21st, hundreds of organizations across the world will be holding workshops, fairs, and lectures for International Archaeology Day.

“International Archaeology Day is a celebration of archaeology and the thrill of discovery. Every October the AIA and archaeological organisations across the United States, Canada, and abroad present archaeological programs and activities for people of all ages and interests. Whether it is a family-friendly archaeology fair, a guided tour of a local archaeological site, a simulated dig, a lecture or a classroom visit from an archaeologist, the interactive, hands-on International Archaeology Day programs provide the chance to indulge your inner Indiana Jones.”
– AIA Website

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It’s All Relative: Archaeology as an Early 20th Century Profession

By Joel Wodhams

Imagine that you are an archaeologist working shortly after the First World War. It’s your first excavation, and you have found small fragment of pottery. What questions would you ask?

Was one of your questions “how old is it”? This is a core question that can be tricky to answer. From 1914 to 1940, archaeologists refined stratigraphy, seriation, and typology in an effort to better understand the age of an object, and of the site as a whole. Read more

Interview with Bioarchaeologist Dr. Andrew Nelson

Dr. Andrew Nelson, Western University

MOA had the opportunity to sit down with Dr. Andrew Nelson, an Associate Professor in Anthropology at Western University, to discuss some of his more recent work, including his contribution to the Art Gallery of Ontario’s Small Wonders exhibition, which includes a Virtual Reality Medieval Prayer Bead, now available at MOA.

Andrew’s research interest are focused in two major subfields of anthropology: biological anthropology and archaeology. When he is not scanning artifacts in Sustainable Archaeology or working on the many research projects at Western University, Andrew can be found navigating the complexities of archaeological sites both local and abroad. Read more

The Classificatory-Descriptive Period: Explorers and Romance

Written by MOA Exhibition Intern Joel Wodhams

What do you think of when you think “archaeologist?” Don’t try to be too correct. Have some fun. When I think of an archaeologist I cannot help but imagine an Indiana Jones-like figure: someone exploring jungles and deserts in search of mysteries from the ancient world. This isn’t what archaeology is today, but it is part of the undeniable charm and romance of archaeology. Read more