Researchers find 'needle in a haystack' as lakebed yields microscopic clues about submerged archeological sites

Jun 13, 2011

After drilling for clues under the bed of a lake in south-eastern Ontario, a McMaster researcher has turned up evidence of human activity that has been submerged since water covered it thousands of years ago.

Lisa Sonnenburg, an instructor in the School of Geography & Earth Sciences, led a team that found tiny flakes of stone left behind in tool making that took place on land that now forms part of the bottom of Rice Lake, near Peterborough, Ontario.

The discovery is significant because it represents the first use of such accumulations of stone chips, called microdebitage, to pinpoint underwater archeological sites. 

I was excited when I first saw it under the microscope, but of course I had to make sure I was seeing what I was actually seeing, says Sonnenburg. Everyone had told me, Youre not going to find anything. Youre looking for a needle in a haystack. Lo and behold, we found the needle in the haystack.

Sonnenburg collaborated with colleagues Joe Boyce and Ed Reinhardt, also of the School of and Earth Sciences. Their research, is published online in the journal Geology.

Water levels at Rice Lake have fallen and risen in the 10,000 years since the glaciers receded, Sonnenburg explains. Once the ice was gone, the lake became a magnet for human settlement, and today its shores are rich in archeological evidence.

Sonnenburg said researchers at nearby dry-land sites such as Serpent Mounds had suggested it was possible that settlements had existed on adjacent land that was later flooded.

She and her team first mapped out the lakebed using scanning technology to search for likely sites.

Then they drilled out and carefully examined 16 core samples taken from selected points around a 10 km section of the lake.

In three of the core samples, they discovered small flakes of stone -- tiny deposits with large implications. Under an electron microscope, the fragments showed the marks of being worked by humans, suggesting the flakes had come from tool making, and establishing microdebitage as a new source of evidence in underwater archeology.

This summer, Sonnenburg is using similar methods as she participates in a larger project that is mapping underwater structures in Huron, also believed to have been used by humans before they were submerged.

McMaster University, one of four Canadian universities listed among the Top 100 universities in the world, is renowned for its innovation in both learning and discovery. It has a student population of 23,000, and more than 140,000 alumni in 128 countries.

Explore further: Radioisotope studies show the continental crust formed 3 billion years ago

Related Stories

Giant stone-age axes found in African lake basin

Sep 10, 2009

( -- A giant African lake basin is providing information about possible migration routes and hunting practices of early humans in the Middle and Late Stone Age periods, between 150,000 and 10,000 ...

Life in an Antarctic lake

Feb 04, 2011

( -- UC Davis geologists have been using laser scanning and underwater video to capture images of life in an ice-covered Antarctic lake.

Underwater exploration seeks evidence of early Americans

Jul 09, 2009

Where the first Americans came from, when they arrived and how they got here is as lively a debate as ever, only most of the research to date has focused on dry land excavations. But, last summer's pivotal underwater exploration ...

Recommended for you

ESA image: Northwest Sardinia

8 hours ago

This image over part of the Italian island of Sardinia comes from the very first acquisition by the Sentinel-2A satellite.

Experiments open window on landscape formation

Jul 02, 2015

University of Oregon geologists have seen ridges and valleys form in real time and—even though the work was a fast-forwarded operation done in a laboratory setting—they now have an idea of how climate ...

NASA image: Canadian wildfires continue

Jul 02, 2015

Canada is reeling from an early fire season this year as dozens of fires ravage at least three provinces of the country. All of the following reports are as of July 2, 2015.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.