Obsidian, naturally occurring volcanic glass, is smooth, hard, and far sharper than a surgical scalpel when fractured, making it a highly desired raw material for crafting stone tools for most of human history. In fact, obsidian tools continued to be used throughout the ancient Middle East for millennia beyond the introduction of metals, and obsidian blades are still used today as scalpels in specialised medical procedures.
In an interdisciplinary collaboration, researchers from social and earth sciences studied obsidian tools excavated from the archaeological site of Tell Mozan, located in Syria near the borders with Turkey and Iraq. Using novel methods and technologies, the team successfully uncovered the hitherto unknown origins and movements of the coveted raw material during the Bronze Age, more than four millennia ago.
Most of the obsidian at Tell Mozan (and surrounding archaeological sites) originated from volcanoes 200km away in what is now eastern Turkey, as expected from models of ancient trade developed by archaeologists over the last five decades. However, the team discovered a set of exotic obsidian artefacts originating from a volcano in central Turkey, three times farther away. Just as important as their distant origin is where the artefacts were found: a royal palace courtyard. The artefacts were left there during the height of the world’s first empire, the Akkadian Empire, which invaded Syria in the Bronze Age. The find has exciting implications for understanding links between resources and empires in the Middle East.
Dr Ellery Frahm, Marie Curie Experienced Research Fellow at the University of Sheffield’s Department of Archaeology, led the research. He said: “This is a rare, if not unique, discovery in Northern Mesopotamia that enables new insights into changing Bronze-Age economics and geopolitics. We can identify where an obsidian artefact originated because each volcanic source has a distinctive ‘fingerprint’. This is why obsidian sourcing is a powerful means of reconstructing past trade routes, social boundaries, and other information that allows us to engage in major social science debates.”
Not only did Frahm and his collaborators identify the particular volcano where the artefacts originated, they were able to pinpoint the exact flank of the volcano where the obsidian was collected and determine that the raw material was gathered from two different spots on its slopes. Such specificity was possible using a combination of scientific techniques, including a portable X-ray analyser that can be brought to archaeological sites and instruments that measure weak magnetic signals within rocks.