Professor studies 300,000 years of history in one site

Geology professor Lucy Wilson prepares to replicate a prehistoric tool by slicing off a section of the rock on the right with a hammer stone on the left.  (Roger Cosman/CBC - image credit)
Geology professor Lucy Wilson prepares to replicate a prehistoric tool by slicing off a section of the rock on the right with a hammer stone on the left. (Roger Cosman/CBC - image credit)
Roger Cosman/CBC
Roger Cosman/CBC

Lucy Wilson grasps a smoothish stone in her right hand and uses it to sharply strike a larger piece of rock.

One well-placed wallop carves off a thin section of rock, creating the exact same kind of stone tool used by prehistoric humans hundreds of thousands of years ago.

Wilson, a geology professor who also teaches courses in geoarchaeology at the University of New Brunswick in Saint John, has been studying stone tools for 40 years. Along the way, she's learned to make a pretty good replica of those tools, too.

Because they survived better than other remnants of life, stone tools offer evidence about how prehistoric humans made things, how they lived and how they evolved over time. They also offer the best evidence of where and when humans lived.

Wilson's particular area of interest is in what tools "pre-modern humans" were using — and for what purpose they were being used — between 50,000 to 500,000 years ago. She said she finds modern humans "boring" since they were able to do so much.

WATCH | Professor recreates paleolithic tool:  

Earlier humans are more of a mystery.

"My interest is what could our ancestors do before they were us? What were they capable of doing? How did they live? That's what we don't know."

Layers reveal many stories

Wilson found the perfect study area in the south of France in the Vaucluse area.

Bau de l'Aubesier is an archaeological dig site carved into the side of a mountain. There are nine or 10 layers of rock in about a dozen metres, "so there's approximately 300,000 years of prehistory within this one site."

Submitted by Lucy Wilson
Submitted by Lucy Wilson

The layers reveal how people visited the area, stayed for a while and left items and traces of their activities, and then left.

Sometimes they returned to the same place and added more material before going away again.

"So we got this whole piled-up mass of stuff."

Wilson said people tended to move around a lot, but seemed to always return to the mountains, where there was lots of material to make stone tools.

"The Bau," as Wilson calls it for short, is a rock shelter. It is like a cave, but it doesn't go back as far into the mountain.

Over thousands of years and during various ice ages, frost in the limestone walls and ceiling caused rocks to break off and fill in the bottom of the opening, thereby sealing in a moment or period of time in the evolution of man.

Submitted by Lucy Wilson
Submitted by Lucy Wilson

"But at the same time, the ceiling retreats upwards, so you always have this open space," said Wilson.

"People came along, sheltered there for a day or a week or two weeks or whatever, and went off again. They left behind some stuff that got buried under more rocks that fell down from the ceiling. Plus wind can blow in smaller grains and things like that."

Creating a picture

What was left behind and buried is what Wilson has been studying for 40 years.

She said the upper layers showed more attention to the quality of the raw material used by Neanderthals. The lower levels reveal remnants of the ancestors of Neanderthals.

Submitted by Lucy Wilson
Submitted by Lucy Wilson

Together with what bones were — and were not — left behind, it all adds up to create a picture of what life was like during the period of time the layer of material was sealed in.

Wilson said bones found at the site indicate Neanderthals hunted wild horses and a type of mountain goat that roamed the area.

Roger Cosman/CBC
Roger Cosman/CBC

One site in particular painted a pretty good picture of what life was like for a specific group that visited the location.

It was a small group of people who only stayed for a few days. In this case, the group brought the raw material to make their tools on site. They killed two or three horses and butchered them and tanned the hides on site.

Wilson said "those stages are all present on the wear of the tools, and then they left and they left behind these tools, which you would think would be perfectly good to be reused."

But the tools are big and sharp and probably difficult to transport.

Submitted by Lucy Wilson
Submitted by Lucy Wilson

She said it appears quite common for groups to leave behind their tools. She said they probably "knew they were going somewhere else where they could get other rocks and make new tools."

Plus, they were quite adept at making tools and good quality rocks were plentiful in the area, so it wasn't such a big deal to leave their tools behind rather than carry the extra weight.

Marjorie Ughetto/Submitted by Lucy Wilson
Marjorie Ughetto/Submitted by Lucy Wilson

Other times, groups would carry raw material to an area and make new tools there. Wilson said that was evident by a piece of rock clearly not having originated in that spot.

One thing that was conspicuous in its absence is human remains at the site.

Except for a few teeth and the odd bone here and there, there's no evidence that bodies were either left or buried at the site.

Wilson said scientists don't actually know what hominins during this period did when group members died.

As she has done almost every year since 1983, Wilson will return to the Bau this year to continue her work at the site.

Robert Russ/Submitted by Lucy Wilson
Robert Russ/Submitted by Lucy Wilson