Earth scientist tracing origins of Maritime Archaic copper artifacts

Aug 1st, 2019

Kelly Foss

Earth scientist tracing origins of Maritime Archaic copper artifacts

Uncovering a mystery thousands of years old.

That’s what Dr. Derek Wilton, Honorary Research Professor in the Faculty of Science’s earth sciences department, is doing in collaboration with The Rooms’ museum division.

Dr. Wilton is using Memorial’s Laser Ablation Inductively Coupled Plasma Mass Spectrometry laboratory to study archaeological samples of native copper with the goal of determining where the copper originated.

He is joined on the project by Dr. Patricia Wells, director of the Arctic Institute of North America at the University of Calgary.

‘Fingerprinting’ copper

Lori Temple, collections manager at The Rooms in St. John’s, visited the lab in March with Maritime Archaic artifacts made of copper collected in Newfoundland and Labrador.

Dr. Wilton used the machine’s laser to generate fine particles from the artifacts, which were then transported to its mass spectrometer for elemental and isotopic analysis.

“This machine is an ideal tool for doing archaeological work because it’s non-destructive,” said Dr. Wilton. “That’s why The Rooms is allowing us to analyze these artifacts.”

The information gathered by the equipment allows him to geochemically “fingerprint” the copper in order to compare it to samples from other North American deposits.

“Native copper is essentially pure copper hosted by rocks,” explained Dr. Wilton.

“Because it was the first easily accessible metal and very malleable, ancient peoples plucked it out of the rock or gathered it from river gravels and used it in jewelry and tools, which they traded over large areas of North America.”

The copper they used came primarily from four areas: the Keweenaw Peninsula in Michigan; Coppermine River in the North West Territories; small occurrences from the eastern North Atlantic seaboard (Nova Scotia-New England); and Seal Lake, Central Labrador.

Researchers have previously conducted analysis of the copper from three locations and on traded artifacts. But the chemistry of the native copper from Seal Lake had not yet been investigated.

The Rooms’ collection

A few years ago, the two researchers visited The Rooms and viewed the collections and helped to confirm which artifacts were actually made of copper.

“They have artifacts from all over Newfoundland and Labrador, and many had been described by archaeologists, when they originally found it, as copper,” he said.

“So, we sorted through what was described as “copper” artifacts to determine if that was accurate, and now finally we have received permission to take a closer look at them in the lab.”

Fifty years of knowledge

Dr. Wilton studied the nature of copper occurrences in the Seal Lake region in the ’80s.

His interest in the area was reignited a few years ago when he age-dated the copper occurrences from the area.

“Other geologists often ask me about the composition of the native copper since I’m the only one who has actually worked with it in the past 50 years,” he said.

“It’s the last area of native copper mineralization in North America that’s not well-known to modern geology. However, because the Seal Lake area was a major trading route, it has great archaeological potential.”

Tracing their origin

Armed with this new information about the chemistry of the copper from Labrador and about the artifacts from The Rooms, plus information previously collected from the other North American copper sites, the researchers now hope to trace the artifacts back to their origin.

“If we can trace where the copper in these artifacts came from, it can provide new information on trading paths, how far people travelled and more,” said Ms. Temple.

“This is a wonderful opportunity to work with researchers and learn more about these objects and what they can tell us about the ancient peoples who utilized them.”