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Obsidian discovery reveals its eastern origins


Archaeologists from the University of Texas Arlington (UTA) have found obsidian flakes at the bottom of Lake Huron in North America, more than 4000 kilometres away from their quarried source in Oregon.

The 9000-year old obsidian was labelled “the earliest and most easterly occurrence of western obsidian in the continental United States” by a research article published in the journal PLOS One.

The article described obsidian as an “exotic exchange commodity” across eastern North America, and that its discovery in Lake Huron revealed the extent of such trading of that era.

“It seems probable that these specimens arrived in the Great Lakes through multiple hands, rather than through any direct access to the central Oregon obsidian source,” the article stated.

“The artifacts reported therefore likely reflect the existence of continent-wide social networks that extended west to east across the recently deglaciated landscapes of North America at the end of the Pleistocene [era].”

Obsidian is a rock formed when molten rock cools too quickly for atoms to be arranged into a crystalline structure, resulting in a smooth, glassy texture.

The researchers focused their work underwater as water levels during the era of interest were much lower.

Ashley Lemke was a part of the research team, as a professor of sociology and anthropology at University of Texas at Arlington (UTA).

She told UTA this unprecedented find showed the importance of their work.

“These are very small pieces that have very large stories to tell,” Lemke told UTA. “Obsidian from the far western United States is rarely found in the east.

“This particular find is really exciting because it shows how important underwater archaeology is.

“The preservation of ancient underwater sites is unparalleled on land, and these places have given us a great opportunity to learn more about past peoples.”

The Wagontire obsidian source was more than 4000km from the sample’s point of discovery, in Lake Huron.
Image: PLOS One


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