Investigating how and when some of the first humans entered North America

For decades scientists have hypothesized that the first inhabitants to enter the New World arrived some 12-15,000 years ago via the Bering Land Bridge. After the fall of the Soviet Union in 1991, researchers from North America and the former Soviet Union joined forces in an attempt to confirm the land bridge hypothesis. It was believed that when scientists from these two continents got together that it would be a simple matter of comparing their respective datasets. Despite all attempts, no one has yet been able to unequivocally demonstrate that a migration from northeast Asia to North America occurred via the Bering Strait 12-15,000 years ago. One approach, focused on the analysis of obsidian, is providing new clues to the peopling of the Americas. Obsidian—a volcanic glass was widely used by prehistoric people to manufacture tools—has unique chemical fingerprints, specific to individual volcanoes, that allows artifacts made from obsidian to confidently be assigned to their geologic source. By sourcing archaeological obsidian to the volcano where it was produced, the Smithsonian’s Museum Conservation Institute in collaboration with National Museum of Natural History researchers hopes to identify the earliest movement of obsidian and people between Northeastern Russia and the Americas. Using portable X-ray fluorescence and laser ablation-inductively coupled plasma-mass spectrometry to identify the chemical fingerprints of obsidian artifact from museum and research collections, MCI is tracing the movements of prehistoric people and examining the trade networks and social interaction across present-day Alaska and eastern Siberia.