Washington. Coastal Range North Cascade Mountains Basalt lava Plateau 10,000 year old glaciated...
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Transcript of Washington. Coastal Range North Cascade Mountains Basalt lava Plateau 10,000 year old glaciated...
Washington
Washington
Co
astal Ran
ge
No
rth C
ascade M
ou
ntain
s
Basalt lavaPlateau
10,000 year old glaciated land
Rivers of WashingtonExcellent drainage patterns and a through-flowing river
Farm Land
No tin or iron
http://www.dnr.wa.gov/Publications/ger_ftg1_yakima_valley_wine_country.pdf
Volcanoes inWashington
Geological Provinces of Washington
Vo
lcan
ic C
asca
de
Mo
un
tain
s
Northern Cascade Mountains
OlympicPeninsula
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
Permian Rocks: 250 million years ago
Not here
But remember this one in Idaho and eastern Oregon & Washington
And here
Hig
h C
asca
des
Northern Cascades
Willapa Hills
The Columbia Plateau
plutonic & metamorphic rocks
Columbia Plateau
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 crustWhat 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 oldColumbia Basalt lava flows
Cross Section
Source area for basalt lavas
No
rth
Am
eric
anC
on
tin
enta
l Cru
st
1–2
bill
ion
yea
rs o
ld
Permian Rocks: 250 million years ago
Not here
Source of the basalts of Oregon & Washington
North AmericanContinental Crust 1–2 billion years old
Oldest ExoticPacific terrane
Younger ExoticPacific terranes
Source of Lava Flows; SE Washington
On the British Columbia