What was J Harlen Bretz theory?
J Harlen Bretz was a geologist who launched one of the great controversies of modern science by arguing, in the 1920s, that the deep canyons and pockmarked buttes of the arid “scablands” of Eastern Washington had been created by a sudden, catastrophic flood — not, as most of his peers believed, by eons of gradual …
Where did J Harlen Bretz live?
Bretz met his wife Fanny Chalis at college – she was also studying biology – and they married in 1906. They had two children: Rudolf and Rhoda. J Harlen Bretz died, age 98, on February 3, 1981, at home in Homewood, Illinois. He was survived by his son and daughter.
What was Pardee’s evidence?
In 1942, Pardee published Unusual Currents in Glacial Lake Missoula. Pardee discovered that the “giant ripple marks” that are seen in the Camas Prairie, indicating an average height of 15-30 feet and wavelength of 250 feet. The ripple marks are evidence that deep and swift flowing currents passed through this area.
What was the source of water for Bretz’s flood?
According to Pardee, an ice dam had formed (Exhibit J), blocking the Clark Fork River in Montana, creating a huge lake. When the ice broke, enormous quantities of water thundered down the Clark Fork Valley toward Spokane, Washington. This was the source of water for Bretz’s catastrophic flood.
Who discovered the Missoula Floods?
J Harlen Bretz
| Harley “J Harlen” Bretz | |
|---|---|
| Nationality | American |
| Other names | Harlan J. Bretz, Harland J. Bretz |
| Alma mater | Albion College, AB 1905 University of Chicago, Ph.D. geology 1913 |
| Known for | Missoula Floods hypothesis, overturned uniformitarianism |
Where did the Missoula flood start?
These floods were the result of periodic sudden ruptures of the ice dam on the Clark Fork River that created Glacial Lake Missoula. After each ice dam rupture, the waters of the lake would rush down the Clark Fork and the Columbia River, flooding much of eastern Washington and the Willamette Valley in western Oregon.
What evidence did geologists use to determine that the scablands were created by massive floods?
The scabland also contain what geologists call butte-and-basin topography. The massive floods scoured lengthy grooves in the underlying basalt, and then gouged out potholes and rock basins. Subsequent flooding created vertical walls of basalt which became temporary cataracts and then dry waterfalls.
How did the Missoula Floods occur?
Glacial Lake Missoula formed as the Cordilleran Ice Sheet dammed the Clark Fork River just as it entered Idaho. The rising water behind the glacial dam weakened it until water burst through in a catastrophic flood that raced across Idaho, Oregon, and Washington toward the Pacific Ocean.
Why did Lake Missoula flood?
Who discovered Missoula Floods?
Geologist J Harlen Bretz first recognized evidence of the catastrophic floods, which he called the Spokane floods, in the 1920s.
