2014 nature night: crooked river caldera by carrie gordon
DESCRIPTION
In 2007, local geologists discovered one of the largest ancient volcanoes in the world right here in Central Oregon! Straddling three counties, the Crooked River Caldera encompasses 425 square miles, stretching from Smith Rock State Park nearly to Prineville reservoir. Join Ochoco National Forest geologist Carrie Gordon for a tour of this immense caldera and its volcanic history that is the story of Central Oregon. Learn about this ancient volcano’s catastrophic eruption and subsequent filling in that has shaped the landscape we see today. Carrie Gordon is the Forest Geologist on the Ochoco National Forest and Crooked River National Grassland for the US. Forest Service. She holds a BA in Geology from Central Washington State College and is a Registered Geologist in the States of Oregon and Washington. Carrie has worked in Central Oregon since 1992 and was part of the team of geologists that discovered Central Oregon’s Crooked River Caldera. Carrie has had a life-long fascination with the land and the rocks, listening to the stories they tell.TRANSCRIPT
1Image courtesy National Park ServiceDeschutes Land Trust 2014
Crooked River Caldera,
a Super Volcano
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Geology and Landforms of Central Oregon
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Empire State is 1, 250 ft. tall.
= 4.5 Billion Years
Last 60 Million Years
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GEOLOGY OF THE NORTH HALF OF THE LOWER CROOKED BASIN, CROOK,
DESCHUTES, JEFFERSON, AND WHEELER COUNTIES, OREGON.
Jason D. McClaughry1, Mark L. Ferns1, and Caroline L. Gordon2
1. Oregon Department of Geology and Mineral Industries, Baker City Field Office, 1510 Campbell Street, Baker City, OR 97814
2. United States Forest Service, Ochoco National Forest and Crooked River National Grassland, 3160 NE 3rd St., Prineville, OR 97754
Funded in part by the USGS under the National Cooperative Geologic Mapping program under assistance awards 05HQAG0037 and 06HQAG0027
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E. L. Orr and W. N. Orr, “Geology of Oregon,” Kendall/Hunt Pub. Co., 5th Edition, 1992.
Geologic/Physiographic Provinces of Oregon
Making Connections:
• Oregon’s ecology is closely tied to Oregon’s geology.
Ecoregions of Oregon
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High Cascades
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Blue Mountains
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Columbia Plateau
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Basin and Range
10Parks and Plates
©2005 Robert J. Lillie
Most of Oregon and Washington has
been added to the edge of the
continent in the past 150 million
yearsMaterial added since then by
Subduction and Terrane Accretion
Coastline 150 Million Years Ago
11http://cpgeosystems.com/paleomaps.html
Opening of the
Atlantic ocean
150Million Years
Ago
Jurassic
Ron BlakeyNorthern Arizona
University
12http://cpgeosystems.com/paleomaps.html
140Million Years
Ago
Cretaceous
Ron BlakeyNorthern Arizona
University
13http://cpgeosystems.com/paleomaps.html
130Million Years
Ago
Cretaceous
Ron BlakeyNorthern Arizona
University
14http://cpgeosystems.com/paleomaps.html
115Million
Years Ago
Cretaceous
Ron BlakeyNorthern Arizona
University
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http://cpgeosystems.com/paleomaps.html
50Million
Years Ago
Eocene
Ron BlakeyNorthern Arizona
University
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http://cpgeosystems.com/paleomaps.html
40Million Years
Ago
Eocene
Ron BlakeyNorthern Arizona
University
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Geologic History - Tectonic Setting
Faults!!!
John Day River
Deschutes River
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Lithology Map (Rocks!!)
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150-60 Million Years ago …
Ammonites
Warm Tropical Seas!!
Geologic History
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Geologic map of the north half of the Lower Crooked Basin
Prineville
Wildcat Mtn.
Crooked River
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Formation of a
caldera
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Clarno Formation ~44 to 39 Ma
Clarno Formation - Eocene Epoch44-39 Million Years ago
Wildcat Mountain
Brennon Palisades
Tropical Climate
First of 2 Major Volcanic Episodes
Ocean Front Property
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Steins Pillar
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Geologic map: Wildcat Mountain Caldera ~40 Ma
Steins Pillar tuff
Andesite &Dacite porphyry43.8 Ma
Hash Rock rhyolite39.4 Ma
Andesite41.5 Ma
Hwy 26
Mill Creek
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Wildcat Mountain caldera
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Rhyolite intrusions within the Wildcat Mountain caldera
Twin Pillars
Forked Horn Butte
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Wildcat Mountain caldera
Steins Pillar Tuff
Crooked River caldera- Tuff of Smith Rock– Monkey Face
John Day
Clarno
Clarno
John Day
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John Day Formation ~36 to 25 Ma
Ochoco Reservoir
Prineville Res.
Lk. Billy Chinook
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John Day Formation - Oligocene Epoch 36-25 Million Years ago
Big Summit Prairie
Temperate Climate
2nd Major Volcanic Episode
Coastline on the Eastern Edge of the Willamette Valley
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2 mm
Gray Butte
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Mahogany Mountain caldera - Leslie Gulch tuff 15 Ma
Crooked River caldera - Smith Rock tuff 29.5 Ma
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Crooked River Caldera -29.5 Ma
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Looking across the Caldera!
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Rhyolite intrusions
Tuff of
Smith Rock Rhyolite
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Hydrothermal deposits
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Modern examples from the Yellowstone caldera
41Yellowstone Caldera
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http://cpgeosystems.com/paleomaps.html
25Million Years
Ago
Oligocene
Ron BlakeyNorthern Arizona
University
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http://cpgeosystems.com/paleomaps.html
15Million Years
Ago
Miocene
Ron BlakeyNorthern Arizona
University
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Miocene Epoch25-16 Million Years ago
Mt. Pisgah
N. Fork Crooked River
Semi-arid Climate Emerging
Thick Columbia River Basalt flows pouring out across the NW
Picture Gorge Basalt Source near Monument
45http://cpgeosystems.com/paleomaps.html
8Million Years
Ago
Miocene
Ron BlakeyNorthern Arizona
University
46http://cpgeosystems.com/paleomaps.html
3Million Years
Ago
Pliocene
Ron BlakeyNorthern Arizona
University
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Neogene Rocks ~16 to 3 Ma
Includes: Prineville basalt, Simtustus Fm., Deschutes Fm.
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Deschutes Formation (~9 to 3 Ma)
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The Geologic map for Prineville
Ochoco Viewpoint
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The geologic landscape at Prineville:
Basalt of Stearns Ranch3-4 Ma
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Quaternary ~1.8 Ma to present
Includes: basalt from Newberry volcano and
Alluvium
Ochoco Reservoir
Lake Billy Chinook
Smith Rock St. Park
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Large Volcanoes Erupting – Pleistocene Epoch1.8 Million Years to 11,700 years
Mt. Hood
Mt. Jefferson
Mt. Mazama
Inter-canyon Flow Basalts
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Smith Rock State Park
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http://cpgeosystems.com/paleomaps.html
Laurentide glaciation
12,500Years Ago
Holocene
Ron BlakeyNorthern Arizona
University
55http://cpgeosystems.com/paleomaps.html
Present Day
Now
Ron BlakeyNorthern Arizona
University
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Holocene Epoch11,700 years to Present
Habitat for Wildlife and PlantsMt. Mazama Ash = Soil Additive
Mt. St. Helens Ash Fall
Mt. Mazama
Geologic map of the west part of the Lower Crooked Basin
A A’
Rin
g-fractu
re
Clarno Fm.
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The Calderas are
The Resource
*Crooked River CalderaPrineville
Wildcat Caldera
Smith Rock
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Oregon’s Super Caldera
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Geologic Foundation
Our Volcanic Past has brought us a wonderfully complex environment!
We’re at the apex of 4 physiographic provinces.
We live with Geology
Geologic history that includes Major Volcanic Episodes
The Calderas – Wildcat Mountain and Crooked River
Smith Rock/Gray Butte Grizzly Butte Powell Butte
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