Analytical Techniques in Archaeology

Analytical Techniques in Archaeology

Archaeology is not just the practice of digging. Once an excavation ends, the hard work of examining and interpreting artifacts begins. For every day in the field, there are months of lab work, researching, documenting, and conserving each find. While much can be learned from an artifact’s appearance, so much more can be learned when we go beyond what we can see. Special analytical tools borrowed from many scientific fields allow us to zoom in and learn more!

Author: Kim Kenyon, Senior Conservator and Co-PI, QAR Lab

Archaeology is not just the practice of digging. Once an excavation ends, the hard work of examining and interpreting artifacts begins. For every day in the field, there are months of lab work, researching, documenting, and conserving each find. While much can be learned from an artifact’s appearance, so much more can be learned when we go beyond what we can see. Special analytical tools borrowed from many scientific fields allow us to zoom in and learn more!

X-ray fluorescence (XRF) is a spectroscopy technique, a method using the properties of light to determine what something is made of, that is becoming widely popular in archaeology because it is relatively affordable and can be used almost anywhere. This tool is helpful for identifying the elements that make up an object. When we discover artifacts on an excavation, they are not always immediately recognizable. XRF can quickly reveal what an artifact is composed of, which helps us understand its relevance to the site and assists us in making good decisions regarding an artifact’s conservation plan and long-term care.

QAR staff uses XRF to analyze an artifact.
Using the portable XRF to determine the elemental makeup of a medical syringe from QAR.

Studying specific isotopes of elements (varieties of the same element that are atomically different) such as oxygen, carbon, nitrogen, strontium, and sulfur, found in archaeological bone can indicate where an individual was raised and what their diet was like. Analysis of the skeletal remains from Henry VIII’s flagship Mary Rose revealed where individuals came from and has allowed archaeologists to discover some of the identities of these sailors whose names and stories have been lost to time. We are currently using this method to potentially determine where the animal bones found on Queen Anne’s Revenge came from – were they of European origin and part of the ship’s original food supply during its days as the slave-trade vessel La Concorde, were they taken on board in West Africa, or were they New World species acquired in the Caribbean?

Peptide mass fingerprinting (PMF) uses collagen, a protein found in animal bones, skin, and muscle, to identify the species of animal that leather objects came from. One project uses this technique to analyze books said to be bound in human skin, a popular yet largely false rumor through the ages. We recently worked with scientists at the Anthropodermic Book Project to determine the origins of leather from the La Concorde/Queen Anne’s Revenge shipwreck site and found that we have samples of cattle, pig, and horse leather. This allows us to better understand these small fragments and the parts they played on the ship, as the possible remains of clothing and shoes, or even protective coverings for tools, instruments, or weapons.

A fragment of a leather shoe insole from QAR, identified through PMF as cattle skin.
A fragment of a leather shoe insole from QAR identified through PMF as cattle skin.

Thanks to scientific research, there are many ways in which we can analyze artifacts to answer specific questions! While these tools may not have even been created for archaeology, we have learned how to adapt them and apply different scientific methods based in archaeology to solve new research questions, making the field truly interdisciplinary.

 

References:
-Price, T. Douglas and James H. Burton. An Introduction to Archaeological Chemistry. Springer, New York, 2011.
-“The Many Faces of Tudor England.” The Mary Rose. Accessed January 28, 2021. https://maryrose.org/news/the-many-faces-of-tudor-england
-“The Science.” The Anthropodermic Book Project. Accessed January 28, 2021. https://anthropodermicbooks.org/about/the-science/

Images:
-Using the portable XRF to determine the elemental makeup of a medical syringe from QAR. Image by NC Department of Natural and Cultural Resources.
-A fragment of a leather shoe insole from QAR, identified through PMF as cattle skin. Image by NC Department of Natural and Cultural Resources.