"This was the stage when humans gradually shifted from hunting large mammals like mastodon and caribou to fishing, gathering and agriculture," said anthropologist John O'Shea. "But because most of the places in this area that prehistoric people lived are now under water, we don't have good evidence of this important shift itself– just clues from before and after the change.
"One of the enduring questions is the way the land went under water. Many people think it must have been a violent event, but finding this large wood object just sitting on the bottom wedged between a few boulders suggests that the inundation happened quickly but rather gently. And this in turn suggests that we'll find more intact evidence of human activity in the area."
With support from the National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA), O'Shea and U-M colleague Guy Meadows began exploring the area in the middle of modern Lake Huron several years ago. In 2009 they reported finding a series of stone features that they believe were "drive lanes" used by ancient PaleoIndian hunters to funnel caribou to slaughter, a technique still used today by the Inuit. These drive lanes were located on the Alpena-Amberley Ridge, a land connection across the middle of modern Lake Huron that linked northern Michigan with central Ontario during the low-water periods of the Pleistocene and early Holocene ages.
Since that discovery, O'Shea and Meadow have worked on identifying human campsites, which are typically located away from hunting areas. Piloting their 25-foot boat, the S/V Blue Traveler, about 40-60 miles out into Lake Huron from Alpena, Michigan, the researchers first spotted the ancient wood object using a small hand-deployed remote operated vehicle (ROV) equipped with a video camera. Then a team of divers – including O'Shea – went down about 100 feet to retrieve it.
Initially stored in a PVC tube filled with lake water, the specimen's age has now been fixed using carbon dating. It is currently undergoing more detailed analyses to determine whether there has been human modification, which visual examination suggests. "The first thing you notice is that it appears to have been shaped with a rounded base and a pointed tip," O'Shea said. "There's also a bevel on one side that looks unnatural, like it had to have been created. It looks like it might have been used as a tent pole or a pole to hang meat."
In addition to the wood specimen, the U-M researchers have collected many other samples from the bottom of the lake that they hope will provide clues about the environment before it was submerged by the rising lake water. Some of the samples are now being analyzed at U-M, while others are being analyzed by a Canadian expert on submerged site reconstruction and microdebitage – the examination of flakes of stone that are less than one millimeter in diameter, produced in large quantities when stone tools were made.
So far, according to O'Shea, quantities of pine pollen and charcoal have been found. "Slowly, the environmental picture is filling in," he said. "There was a marsh close by this site. It seems we're narrowing in on people, but of course forest fires could have created the charcoal as well as cooking fires. So we need to wait for the analyses to be sure about what we've got here."
O'Shea and colleagues will also need to wait for calmer weather before they can resume their search for evidence of human life under the great lake.
This research was carried out in collaboration with NOAA's Thunder Bay National Marine Sanctuary and with the Great Lakes Division of the U.S. Navy's Sea Cadets Corp, both based in Alpena, Michigan.
O'Shea is a professor of anthropology at the U-M College of Literature, Science, and the Arts (LSA) and Curator of Great Lakes Archaeology at the U-M Museum of Anthropology. Meadows is a professor of physical oceanography at the U-M College of Engineering.
Diane Swanbrow | EurekAlert!
Welcome Committee for Comets
19.07.2019 | Technische Universität Braunschweig
Sea level rise: West Antarctic ice collapse may be prevented by snowing ocean water onto it
18.07.2019 | Potsdam-Institut für Klimafolgenforschung
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
19.07.2019 | Physics and Astronomy
19.07.2019 | Physics and Astronomy
19.07.2019 | Earth Sciences