Mat
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Cape Perpetua Scenic Area,Oregon
The Dynamic Landscape ofOregon’s Coast: A Tale of
Beauty and the Beast
Bob LillieProfessor of Geology
Certified Interpretive TrainerOregon State University
Oregon Coast Region of theOregon Master Naturalist Program
Unit 9: Geology of the Oregon Coast
Cape Perpetua Scenic Area, OregonFebruary 26, 2011
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Goal and Objectives for Coastal Master NaturalistGeology Training
• Goal: To provide Oregon Master Naturalists with anoverview of Oregon Coast geology and appreciation ofthe Coast’s geologic stories and processes.
• Master Naturalists will be able to:1. Explain how the Oregon Coast Range formed.2. Discuss geological hazards of the Oregon Coast.3. Incorporate the Coast’s geological landscape and
processes into interpretive programs focused onbiology, ecology, and human history.
Devil’s Churn, Cape Perpetua Scenic Area, Oregon
Marine GardensNewport, Oregon
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Oregon Coast Region of theOregon Master Naturalist Program
Unit 9: Geology of the Oregon Coast
Cape Perpetua Scenic AreaFeb. 26, 2011
Morning: 9:00 - Plate Tectonics and Landscape
Formation10:00 - Ongoing Coastal Processes11:00 - Coastal Geological Hazards12:00 - Lunch at Visitor Center (bring own)
Afternoon:12:30 - Hike “Trail of the Restless Waters”
- Brainstorm: Geology observations and connections
3:00 - Interpretive Methods4:00 - Developing Themes for Oregon Coast
Geology5:00 - Adjourn
Agenda
Marine GardensNewport, Oregon
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Oregon Coast Region of theOregon Master Naturalist Program
Unit 9: Geology of the Oregon Coast
1. Plate Tectonics and LandscapeFormation:
Building OregonCascadia Subduction ZoneColumbia Plateau Basalt
2. Ongoing Coastal Processes:Dynamic Duo: Uplift and ErosionCoastal Headlands
3. Coastal Geological Hazards:EarthquakesTsunamisLandslides
4. Interpretive Methods:Presenting Coastal Geology toCoastal Audiences
Topics
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1. Plate Tectonics
1. Plate Tectonics and LandscapeFormation:
Building OregonCascadia Subduction ZoneColumbia Plateau Basalt
2. Ongoing Coastal Processes:Dynamic Duo: Uplift and ErosionCoastal Headlands
3. Coastal Geological Hazards:EarthquakesTsunamisLandslides
4. Interpretive Methods:Presenting Coastal Geology toCoastal Audiences
The Dynamic Landscape ofOregon’s Coast: A Tale of
Beauty and the Beast
Bob LillieProfessor of Geology
Certified Interpretive TrainerOregon State University
Oregon Coast Region of theOregon Master Naturalist Program
Unit 9: Geology of the Oregon Coast
Cape Perpetua Scenic Area, OregonFebruary 26, 2011
Mar
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Gar
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, New
port,
Ore
gon
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U. S
. Geo
logi
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Mt. St. Helens National VolcanicMonument, Washington
Crater Lake National Park, Oregon
Beauty and the Beast
“The same geological processes that threaten our lives with earthquakes,tsunamis and volcanic eruptions also nourish our spirits by creating theinspiring mountains, valleys, and coastlines of the Pacific Northwest.”
Parks and Plates©2005 Robert J. Lillie
What forms the spectacularlandscapes of national parksand other special places inthe Pacific Northwest?
NATIONAL PARKLANDS
Selected ParklandsOlympicNational Park
Cape AragoState Park
Redwood Nationaland State Parks
Coast Range
Cape PerpetuaScenic Area
Oregon StateParks
NationalPark Service
U. S. ForestService
Bureau LandManagement
Mount Rainier NP
Mt. St. Helens NationalVolcanic Monument
Crater Lake NP
CascadeVolcanoes
Lassen Volcanic NP
Selected Parklands
Mt. Hood
Oregon StateParks
NationalPark Service
U. S. ForestService
Bureau LandManagement
TheBeast
Beauty
and
CascadeVolcanoes
Why are there Two ParallelMountain Ranges in the
Pacific Northwest?
National Park Lands inthe Pacific Northwest
CoastalRanges
Parks and Plates©2005 Robert J. Lillie
Plate tectonics is aboutreading the landscape andmaking connections:
- Why are landscapes similar?- Why are they different?- What we see happening today
can help us understand whathappened in the past ……
NATIONAL PARKLANDS
Landscapes ofnational parksdue to processes:• At plate boundaries
1. Where they pullapart (divergent)2. Where they crashtogether (convergent)3. Where they slidepast one another(transform)
• And at hotspots
• Tectonics:• From the Greek “tecton” - builder
- “architect”• The study of large features
on Earth’s surface and theprocesses that form them.
PLATE TECTONICS©
1977
, Mar
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77, M
arie
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• Large features:– continents– ocean basins– mountain ranges
• and processes:– earthquakes– volcanic eruptions
• due to movement of plates ofEarth’s outer shell.
“PLATE TECTONICS”
Nat
iona
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onau
tics a
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pace
Adm
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ratio
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The Whole Earth andPlate Tectonics
We need to understandwhat goes on inside the
Earth.
Oreo® Psycho-Personality Test www.superkids.com/aweb/pages/humor/050199.sht
Psychologists have discovered that the manner in which people eatOreo® cookies provides great insight into their personalities.Choose which method best describes your favorite method ofeating Oreos: 1. The whole thing at once.2. One bite at a time.3. Slow and methodical nibbles examining the results of each bite
afterwards.4. In little feverous nibbles.5. Dunked in some liquid (milk, coffee …..)6. Twisted apart, the inside, then the cookie.7. Twisted apart, the inside, and toss the cookie.8. Just the cookie, not the inside.9. I just like to lick them, not eat them.10. I don’t have a favorite way because I don’t like Oreos.
6. Twisted apart, the inside,then the cookie.
• You have a highly curious nature.• You take pleasure in breaking things apart
to find out how they work, though you’renot always able to put them back together,so you destroy all the evidence of youractivities.
• You deny your involvement when things gowrong.
• You are a compulsive liar and exhibitdeviant, if not criminal, behavior.
Africa
SouthAmerica
Core
LowerMantle
AtlanticOcean
AsthenosphereLithosphere
Trench
Divergent PlateBoundary:
New LithosphereCreated
Mid-AtlanticRidge
Convergent Plate Boundary:Lithosphere Recycled back into
Deeper Mantle
Mod
ified
from
Ham
blin
and
Chris
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en, 2
001
Earth is a Giant Recycling Machine!!
Osorno volcano near Puerto Montt, Chilehttp://whatonearth.olehnielsen.dk/volcanoes.asp
Andes Mountains, South America
Mar
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, EAR
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Nor
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200
5)
Parks and Plates©2005 Robert J. Lillie
The Pacific Platemoves
northwestward pastthe North AmericanPlate along the San
Andreas Fault.
TRANSFORMPLATE
BOUNDARY
Nat
iona
l Geo
grap
hic
Soci
ety Forming
Today
45 MillionYears Old
21 MillionYears Old
NorthwestwardPlate Motion
Hawai`i – Emperor Hotspot Track
Parks and Plates©2005 Robert J. Lillie
CascadiaSubduction
Zone
Subduction Zones rim the Pacific Ocean
Parks and Plates©2005 Robert J. Lillie
Subduction of the Juan deFuca Plate forms theCoastal Ranges andCascade Volcanoes
CoastalRanges
CascadeVolcanoes
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Plate Tectonics--Subduction Zone
Parks and Plates©2005 Robert J. Lillie
Juan deFuca Plate North
AmericanPlate
CascadiaSubduction
Zone
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Parks and Plates©2005 Robert J. Lillie
Subducting Juan de Fuca Plate forms two parallelmountain ranges in the Pacific Northwest.
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Parks and Plates©2005 Robert J. Lillie
Oceanic sediment and basalt scraped off subducting plate,forming Coastal Mountains.
Sediment andBasalt Scraped offSubducting Plate
Olympic and otherCoastal Mountain
Ranges
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Parks and Plates©2005 Robert J. Lillie
Subducting plate dehydrates, forming Cascade Volcanoes.
Plate SweatsHot Water
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Parks and Plates©2005 Robert J. Lillie
Subducting plate dehydrates, forming Cascade Volcanoes.
VolcanicMountain
Range
Plate SweatsHot Water
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Parks and Plates©2005 Robert J. Lillie
Puget Sound and the Willamette Valley are low-lying regionsbetween the rising mountains.
Puget Sound/Willamette Valley
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Parks and Plates©2005 Robert J. Lillie
NationalParks
represent thetwo different
mountainranges.
Mt. St.HelensNVM
CascadeVolcanoes
National Park Lands inActive Volcanic Arc
Parks in the Cascadesshowcase volcanoesformed above thesweating plate.
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Parks and Plates©2005 Robert J. Lillie
Cascade Mountains,Central Oregon
View looking North
State CapitolGeology Exhibits
http://www.ohs.org/exhibits/traveling-exhibits/oregon-150-years-of-statehood-
150-million-years-in-the-making.cfm
http://www.oregongeology.org/sub/pub&data/capitol-windows.htm
http://oregonstate.edu/leadership/presidentsreport/2008/winter/assembling-oregon
• Jan, 2009 - Jan, 2011• Oregon’s Geology andhow it relates to naturaland cultural history
http://www.ohs.org/exhibits/traveling-exhibits/oregon-150-years-of-statehood-
150-million-years-in-the-making.cfm
http://www.oregongeology.org/sub/pub&data/capitol-windows.htm
http://oregonstate.edu/leadership/presidentsreport/2008/winter/assembling-oregon
• Jan, 2009 - Jan, 2011• Oregon’s Geology andhow it relates to naturaland cultural history
State CapitolGeology Exhibits
Mar
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005)
Parks and Plates©2005 Robert J. Lillie
AGE OF NORTHAMERICANBASEMENT
ROCKS(Billions Years)
Rocks are oldestnear the center of
the continent(continental shield)
and tend to getyounger outward.
Marshak, EARTH (Norton, 2005)
Terrane AccretionA TERRANE consists of crust that is too thick and
buoyant to subduct. The continent grows outward asterranes come crashing in.
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North AmericanPlate
First Terrane
SecondTerrane
Third Terrane
ForthTerrane
Ocean Plate
Safeway Terrane Accretion
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North American
Plate
First Terrane
Second Terrane
Third Terrane
Forth Terrane
OceanPlate