Washington
Washington
10,000 year old glaciated land
Basalt lava
Plateau
Rivers of Washington
Excellent drainage patterns and a through-flowing river
No tin or iron
Farm Land
Volcanoes in
Washington
http://www.dnr.wa.gov/Publications/ger_
ftg1_yakima_valley_wine_country.pdf
Geological Provinces of Washington
Northern Cascade
Mountains
Olympic
Peninsula
Now to the continental glacier
Most Recent Continental Glaciation
100,000 to 17,000 years ago
Notice that glaciers extend
well out into the Pacific Ocean
How did First Nation People
get across Canada and into
the USA and Mexico?
Igneous Rocks of Northern Washington
Area of complex plutonic
igneous and metamorphic rocks
Igneous Rocks not along
the Cascade Trend
And here Permian Rocks:
250 million years ago
Not here
But remember this one
in Idaho and eastern
Oregon & Washington
The Columbia Plateau
Northern Cascades
plutonic & metamorphic rocks
Columbia Plateau
Willapa Hills
Multiple *Basalt lava flows
*Basalt lava flows: similar rock
to Oceanic Crust
Columbia Plateau Basalt Lava Flow
Multiple lava flows
About 4 million years old
Similar to oceanic crust
What rocks were covered by the basalt?
The Source for the Lava Flows of Washington
Exotic subcontinents
rafted in from the Pacific
<100 million years old
4 million year old
Columbia Basalt
lava flows
Cross Section
Source area
for basalt lavas
Permian Rocks:
250 million years ago
Not here
Source of the basalts of
Oregon & Washington
Source of Lava Flows; SE Washington
Younger Exotic
Pacific terranes
Oldest Exotic
Pacific terrane
North American
Continental Crust
1–2 billion years old
On the British Columbia