cataclysms on the columbia: the great missoula floods

Cataclysms on the

Columbia

The Great Missoula Floods

Dr. John Eliot AllenDr. Marjorie BurnsDr. Scott BurnsPortland State University

Ooligan Press, PSU

1) Name for the Floods is Missoula Floods not Bretz Floods

2) Dates are in Calendar Years not C-14 Years

3) Color Photos4) Maps are shaded relief

maps for easier reading5) Rest of the Story added

for history of the Floods6) Totally updated science

of the floods

New Things in the Second Edition of the Book:

Darryl Lloyd photo

In front of Mt. Rushmore

“Five great men in one picture – four of them don’t show”

J Harlen Bretz

Bretz et al in the Grand Coulee, ca 1928

Bretz, circa 1910

Photo: Darryl Lloyd

A “Palouse Island” along I-90, about 5 miles north of Sprague, Washington

Big whorls have little whorls,

Which feed on their velocity:

Little whorls have smaller whorls

And so unto viscosity. JEA p31

Strand lines on the Washington side of the Columbia River Gorge

Bretz, 1933

USGS Controversy

James Gilluly G.R. MansfieldO.E. Meinzer

Revisionists

Ira Allison Richard Foster Flint

J.T. Pardee Breaks the Silence

Vindication

Before Bretz dies in 1981 at 98 years of age

The Rest of the Story1979 photo

Richard Waitt

Burlingame Gulch near Touchet, WashingtonExposing 40 rhythmite beds

Burlingame Gulch near Touchet, WashingtonExposing 40 rhythmite beds

Set S Mt. St. Helens Ash near Mabton in the Yakima Valley

Brian Atwater

Close-up of 2 rhytmites showing varved annual layers of silt and clay

Dating the Missoula FloodsDating the Missoula Floods

• Radiocarbon Dating: 15,300 – 12,700 BP

• Calendar Years (Calibrated Dates: 15,000 – 18,000 years ago)

• 40 events came to Portland area

• 90 events came to Spokane

Altai Mountains

Glacial Lake Missoula:1) 530 mi3 water2) 50 mi3 ice3) 2100 feet deep4) Elevation: 4250 ft.

Ancient beach strand lines can

still be seen

Lake Missoula was ~ ½ the size of Lake

Michigan

Nine Mile Section:1) Pale: river deposits (36)2) Dark: varves (1000)3) oldest: 58 varves

1) 2400 ft. Elevation

2) Up to 500 ft deep

Grand Coulee

Dam

Spokane

Odessa

Potholes in Quincy Basin

Palouse Falls

Wallula Gap

Mt. St. Helens double ash layers, age 13,000 between 29th and 30th layer

Columbia River, west of Philippi Canyon

Gravel bar formed at entrance to Philippi Canyon

Bonneville

Beacon Rock – Columbia Gorge

Rooster Rock (has had different names in the past)

Swan Island

If the Missoula Floods were to occur today

Willamette Meteorite (1902 photo)

1905 exposition

Foreset beds in Durham Pits – now under Bridgeport

15,000 year old soil overlies on older paleosol in the loess

1935 Ira Allison map

Bellevue Erratic – argillite – 1950 measured approx. 160 tons, now approx. 40 tons

Irish Bend south of Corvallis

Floodwaters, entrained sediments and turbid currents that swept across

the Pacific Ocean floor for 700 miles (1100 km).

Normark et al. (2000)

Ancient Cataclysmic Floods5 Ancient Cataclysmic Floods exposed in paleosols near The Dalles

Volcanic Soils on the hills of Dundee, OregonVolcanic soils on the hills of Dundee, Oregon

Terroir Differences in PNWTerroir Differences in PNW

• Washington: 95% of the vineyards are on Missoula Flood sediments; Vigor controlled by irrigation.

• Oregon: 90% of vineyards are on upland vineyards and 10% are on Missoula Flood sediments; Vigor controlled by low nutrient, old soils.

Conclusions - But Not The End of the Story

• 89+ floods, with 40 getting to Portland

• Velocities up to 60 mph

• Flows = 10 x the total flow of all of the world’s rivers

• Effects of the Floods: 16,000 square miles

• Maximum Floods were the first ones: 530 mi3 of water and 50 mi3 of ice; biggest were first floods

Future

• More information from Ancient Cataclysmic Floods

• More information of time of the Floods passing the “Lakes”

• More information from the deep sea record

• New National Park will bring visitors to the region and new research will unlock further secrets