Scientists at MU and other universities are analyzing obsidian materials from volcanic sources all over the world to create a comprehensive database for successful sourcing of obsidian artifacts. Although all obsidian is formed from the same basic material—magma, the molten rock beneath the earth's surface—there are slight variations of various elements in each volcanic eruption. It is often these minor variations that help differentiate the chemical fingerprints. The obsidian database now has more than 250 obsidian sources from the Western Hemisphere that have been fully characterized, and it allows archaeologists to trace an obsidian artifact to the precise outcrop from which the original material was mined with nearly 100% confidence!
The ancient Native American culture known as the Hopewell people was centered in the Ohio River valley more than 1500 years ago. Although there were no obsidian quarries in the area—the nearest were more than a thousand miles away—obsidian artifacts have been discovered in the Hopewellian excavations. How did they obtain obsidian and where was the source? The graph illustrates NAA data for four "nearby" obsidian sources (quarries) located in the Jemez Mountains of New Mexico and Yellowstone National Park in Wyoming. Samples from these quarries have been characterized in MURR's Archaeometry Lab and their chemical fingerprints are part of our extensive database. By analyzing the obsidian artifacts found in the ancient Hopewellian sites in Ohio and matching them against our database, we are helping archaeologists determine the source of their interesting find. Did the obsidian come from New Mexico or perhaps Wyoming? If so, how? We eagerly await their results being published.