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Glacial Lake Ontonagon was one of the first pro-glacier lakes formed during the retreat of the Laurentide Ice Sheet during the end of the Wisconsin Glacial period. The lake was just south of present day Lake Superior but flowed westward toward the Mississippi River due to Lake Superior still being filled with ice. The lake form significant lacustrine deposit over lying a river sand. A recent large scale landslide occurred on an ox bow of the river, with the failure being generated by soil liquefaction in the lower sand unit.
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Glacial Lake Ontonagon and the Development of
Large Scale Landslides
Stan Vitton, PhD, PEMichigan Technological University
Adapted from a presented given at the 59th Annual MeetingInstitute for Lake Superior GeologyHoughton, MI May, 2013
Glacial Lake Ontonagon
• Location
• Glacial Lake Ontonagon
• Spring 2004 Landslide Event
• Landslide Initiation Mechanism
• Summary
Glacial Lake Ontonagon
US-45
Ottawa National Forest Boundary
Landslide Location
US-45
M-26
Rockland, MI
Ontonagon Landslide US-45 and the East Branch of the Ontonagon River
Landslide Location
Original Lake
Ontonagon Drainage
Ontonagon Drainage System
West Branch
Middle Branch
East Branch
South Branch
Landforms of the Upper Peninsula, Draft 2006
Major Landforms
Bedrock Geology of Upper Michigan
Landforms of Upper Michigan
Ontonagon Area - Landforms
USGS Professional Paper 504-BPostglacial Drainage and Stream Geometry of the Ontonagon AreaHack (1965)
USGS Professional Paper 504-B
USGS Professional Paper 504-B
US Corps of Engineers (2010)
Google Earth
Ontonagon Boulder
Glacial Lake Ontonagon
• Location
• Glacial Lake Ontonagon
• Spring 2004 Landslide Event
• Landslide Initiation Mechanism
• Summary
Glacial History of the Great Lakes
Farrand & Drexler, 1985, Late Wisconsin & Holocene History of the Lake Superior Basin
Farrand & Drexler, 1985, Late Wisconsin & Holocene History of the Lake Superior Basin
Farrand & Drexler, 1985, Late Wisconsin & Holocene History of the Lake Superior Basin
Farrand & Drexler, 1985, Late Wisconsin & Holocene History of the Lake Superior Basin
Farrand & Drexler, 1985, Late Wisconsin & Holocene History of the Lake Superior Basin
Farrand & Drexler, 1985, Late Wisconsin & Holocene History of the Lake Superior Basin
Prehistoric climate change due to cosmic crash in Canada September 3, 2013
An artist's rendition of mastodons, camels and a ground sloth before the environmental changes of the Younger Dryas led to their extinction. - Barry Roal Carlsen, University of Wisconsin
The impact occurred about 12,900 years ago, at the beginning of the Younger Dryas period, and marks an abrupt global change to a colder, dryer climate with far-reaching effects on both animals and humans. In North America, the big animals all vanished, including mastodons, camels, giant ground sloths and saber-toothed cats.
Their human hunters, known to archaeologists as the Clovis people, set aside their heavy-duty spears and turned to a hunter-gatherer subsistence diet of roots, berries and smaller game.
"The Younger Dryas cooling impacted human history in a profound manner," says Dartmouth Professor Mukul Sharma, a co-author of the study. "Environmental stresses may also have caused Natufians in the Near East to settle down for the first time and pursue agriculture."
It is not disputed that these powerful environmental changes occurred, but there has long been controversy over their cause. The classic view of the Younger Dryas cooling interlude has been that an ice dam in the North American ice sheet ruptured, releasing a massive quantity of freshwater into the Atlantic Ocean. The sudden influx is thought to have shut down the ocean currents that move tropical water northward, resulting in the cold, dry climate of the Younger Dryas.
But Sharma and his co-authors have discovered conclusive evidence linking an extraterrestrial impact with this environmental transformation. The report focuses on spherules, or droplets of solidified molten rock expelled by the impact of a comet or meteor. The spherules in question were recovered from Younger Dryas boundary layers at sites in Pennsylvania and New Jersey, the layers having been deposited at the beginning of the period. The geochemistry and mineralogy profiles of the spherules are identical to rock found in southern Quebec, where Sharma and his colleagues argue the impact took place.
Glacial Lake Ontonagon
• Location
• Glacial Lake Ontonagon
• Spring 2004 Landslide Event
• Landslide Initiation Mechanism
• Summary
Large Scale Landslide
Lower Unit Alluvial Sand
Upper Unit – Lacustrine
Upper Unit – Lacustrine
Upper Unit – Lacustrine
Upper Unit – Lacustrine
Lower Unit Alluvial Sand
Lower Unit Alluvial Sand
0.0100.1001.00010.0000
10
20
30
40
50
60
70
80
90
100
Upper Sand Layer 790 foot
Upper Sand Layer 760 foot
Middle Sand Layer 730 foot
Lower Sand Layer 710 foot
Grain Size, (mm)
Perc
ent P
assin
g, (%
)
Lower Unit Alluvial Sand
Glacial Lake Ontonagon
• Location
• Glacial Lake Ontonagon
• Spring 2004 Landslide Event
• Landslide Initiation Mechanism
• Summary
Lower Unit Alluvial Sand
Upper Unit – Lacustrine
0.0100.1001.00010.0000
10
20
30
40
50
60
70
80
90
100
Upper Sand Layer 790 foot
Upper Sand Layer 760 foot
Middle Sand Layer 730 foot
Lower Sand Layer 710 foot
Grain Size, (mm)
Perc
ent P
assin
g, (%
)
Lower Unit Alluvial Sand
Clay/Silt Softening at Base of the Slope
Soil Liquefaction in the Transition Zone
Glacial Lake Ontonagon
• Location
• Glacial Lake Ontonagon
• Spring 2004 Landslide Event
• Landslide Initiation Mechanism
• Summary
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