"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!
Using tree-fall patterns to calculate tornado wind speed
25.06.2018 | Ecological Society of America
Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle
22.06.2018 | Technical University of Denmark
Russian researchers together with their French colleagues discovered that a genuine feature of superconductors -- quantum Abrikosov vortices of supercurrent -- can also exist in an ordinary nonsuperconducting metal put into contact with a superconductor. The observation of these vortices provides direct evidence of induced quantum coherence. The pioneering experimental observation was supported by a first-ever numerical model that describes the induced vortices in finer detail.
These fundamental results, published in the journal Nature Communications, enable a better understanding and description of the processes occurring at the...
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
25.06.2018 | Physics and Astronomy
25.06.2018 | Earth Sciences
25.06.2018 | Power and Electrical Engineering