Obsidian artifacts unearthed in Alberta offer new clues on prehistoric trade routes

Wallis Snowdon · CBC News

· Posted: Mar 31, 2025 4:00 AM EDT | Last Updated: 10 hours ago

Inky achromatic shards of volcanic solid unearthed successful Alberta are helping researchers hint the movements of Indigenous radical crossed Western Canada centuries ago. 

Hand-carved arrowheads and jagged spears made of obsidian, a crisp stone formed by volcanic magma, are remnants of immense prehistoric commercialized networks that erstwhile chopped crossed occidental North America.

No volcano has ever erupted successful Alberta, meaning each shard of obsidian recovered successful the state was carried here. With X-ray technology, researchers tin hint each portion backmost to its source.

A caller insubstantial examining artifacts unearthed from Alberta's eastbound slopes suggests bison hunting successful the confederate foothills and a immense speech web on the province's bluish rivers helped administer the stones crossed the province. 

Archaeologist Timothy Allan, the report's author, said helium wanted to amended recognize Alberta's relation successful a immense Indigenous commercialized web that erstwhile spanned much than 3 cardinal quadrate kilometres.

A azygous portion of obsidian apt changed hands galore times.

"The sheer standard of obsidian commercialized tells america that apt millions of radical were successful interaction with 1 another," said Allan, who works with Ember Archaeology, an archaeology and historical resources consulting steadfast based successful Sherwood Park, Alta.

"The scope of the commercialized web was mode much monolithic than we thought." 

Understanding the journeys of obsidian artifacts tin supply caller penetration into however radical moved crossed the scenery and the analyzable taste ties that shaped the continent centuries ago, Allan said.

"It's decidedly portion of our relation successful reconciliation, arsenic archaeologists, to assistance archer these stories."

The research, published by the Archaeological Survey of Alberta, is the latest offering from the Alberta Obsidian Project, an ongoing collaboration of researchers and archaeologists examining the province's immense obsidian record.

Chemistry sealed in time

Over the past decade, task researchers person studied and catalogued much than 1,200 Alberta obsidian artifacts.

The artifacts and the commercialized itself day backmost to a play betwixt 13,000 and 300 years ago, earlier European contact. 

More than 520 archaeological sites person been identified successful the province. The eastbound slopes, which agelong from the alpine slopes of the Rockies down to the foothills, connection the astir specimens.

Fragments person been recovered astatine 285 archaeological sites successful the region. Allan's investigation examined 383 specimens originating from 96 sites.

Obsidian's unsocial qualities made it invaluable for the prehistoric peoples who utilized it, and for archaeologists today.

The sharpest naturally-occurring worldly connected earth, it was prized by Indigenous peoples who carved it into cutting tools and weapons.

Each portion of obsidian, formed by volcanic magma, has a unsocial chemic signature. Using X-ray fluorescence, researchers tin place unsocial geochemical markers and corroborate the provenance of each piece.

"It's formed erstwhile a volcano erupts and lava cools really, truly quickly," Allan said. "Because it cools truthful quickly, it benignant of seals its chemistry successful time."

Each portion is bona fide proof of a long-distance speech successful the past, Allan said. 

"If you find obsidian, you cognize that that worldly has travelled a agelong way." 

Distinct commercialized routes

Allan said Alberta appears to beryllium the bluish borderline of the commercialized network, which stretched crossed the American midwest arsenic acold southbound arsenic Texas, and into Canada arsenic acold northbound arsenic what is present Fort McMurray, Alta.

Artifacts recovered successful Alberta person travelled betwixt 400 and 1,200 kilometres, with the immense bulk coming from Bear Gulch successful Idaho and Obsidian Cliff successful Wyoming's Yellowstone National Park. Other sources see the Anahim Peak and Mount Edziza sites successful B.C.

Bear Gulch specimens accounted for 62 per cent of each samples. Obsidian Cliff examples made up about 30 per cent.

But the information suggests the commercialized routes were chiseled from each other, with the North Saskatchewan River and the Red Deer River acting arsenic earthy boundaries betwixt the trade routes.

People successful what is present bluish Alberta were much connected with tribes to the west, portion radical successful the southbound were much intimately tied with different tribes who lived connected the unfastened plains of the confederate foothills. 

In the north, commercialized appears to person been much sporadic, with obsidian apt moving into Alberta from B.C. on ample east-west stream networks that chopped done the Rockies.

To the south, communal bison hunting seems to person shaped the trade.

Obsidian successful these regions was traded successful comparatively larger quantities and the exchanges look to beryllium portion of a wide societal web shared by radical who lived and harvested unneurotic connected the plains of what is present confederate Alberta and the American Midwest.

Much of the obsidian uncovered successful confederate Alberta originates from sources southbound of the border. Bison jumps — wherever herds were driven disconnected cliffs during ample culls — relationship for immoderate of the highest concentrations of obsidian artifacts successful the province.

A portal into the past

Todd Kristensen, a determination archaeologist with the Archaeological Survey of Alberta, said the information has drawn retired meaningful patterns astir however radical were sharing the onshore and resources.

"We tin usage obsidian to recognize however antithetic Indigenous groups successful antithetic ecological regions adapted to the scenery differently," Kristensen said.

"It's 1 of those small portals that we tin usage to recognize however radical adapted." 

Alberta's obsidian grounds is uniquely positioned to supply a presumption of the past. The probe offers a uncommon glimpse of the ties betwixt assorted Indigenous peoples, Kristensen said.

He said much probe is needed to recognize the taste value of these prehistoric kinship connections — and the chromatic itself — among Indigenous peoples. 

"Obsidian is fascinating due to the fact that it tells america astir quality relationships," helium said. "That's truly uncommon for archaeologists to find."