PaHoeHoe

Pahoehoe basalt, Jordan Craters, Oregon

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Breccia

Volcanic breccia, Leslie Gulch (Owhyees) Oregon.

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Scoria

Scoria. Tethero Butte cinder cone, Redmond, Oregon

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Pumice

Pumice, From eruption of Mount Mazama, Oregon

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Fossil alder leaf, Eocene Sandstone, Herren Formation, Pilot Rock, Oregon.

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Conglomerate

Conglomerate, Gable Creek Formation, Mitchell, Oregon

Greenstone

Cobble, volcanic greenstone, with white plagioclase. Hells Canyon, Oregon.

Sill

Basalt sill in sandstones of the Astoria Formation, Oregon coast near Cannon Beach.

Serpentinite, with slickensides

Serpentinite, Canyon Mountain, Oregon.

Ripple marks and pebble, Long Beach, Washington.

Greenstone

Volcanic greenstone, with vesicles and feldspar. Hells Canyon, Oregon.

Collier glacier and North Sister

Lateral moraine of vanishing Collier Glacier. North Sister, central Cascades, Oregon.

Columnar jointing

Colonnade and entablature, basalt flow, Mount Hood, Oregon.

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Hexagonal (?) columns

Columnar jointing in basalt flow from Mount Adams, WA.

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Columns and platy joints

Columnar jointing with horizontal platy joints. Near The Dalles, Oregon.

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Hackley Jointing

Pomona basalt flow, near Mosier, Oregon.

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Weathered and fresh surfaces, basalt

The freshly-broken surface of this basalt is dark gray to black; the weathered exterior, where iron has oxidized, is brown.

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Platy jointing

Andesite, with platy joints and dis-organized columnar joints. Paradise, Mount Rainier, WA.

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Porphyritic basalt

Steens basalt with large crystals (phenocrysts) of plagioclase, feldspar. Steens Mountain, Oregon.

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Flow-banded rhyolite

Flow banding in rhyolite. Pine Ridge, near Madras, Oregon.

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Mossy columns

Columnar jointing, Columbia River basalt flow, Rufus, Oregon

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Mt. Baker and its andesite

Platy jointing, andesite, Mount Baker, WA

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Vesicular rhyolite

Gas holes (vesicles) in rhyolite, near Ashwood, Oregon.

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Flow-banding

Flow-banding, rhyolite, Warm Springs, Oregon.

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Cross-bedding

Closeup, X-bedding, pebble conglomerates and sandstones, Miocene Astoria Formation, Hug Point, Oregon

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Syncline

cretaceousfoldmitchell

Volcanic greenstone, Wallowa Mountains, Oregon.

GreenstoneWallowas

Volcanic mudflows, (Lahars) Clarno Unit, John day Fossil Beds National Monument, Oregon

CLARNOcliffs

Blueschist, Mitchell, Oregon

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Closeup, blueschist, Mitchell, Oregon.

Gneissxtra

Pencil Shales, Izee, Oregon

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Yellow Aster gneiss, North Cascades, Washingotn.

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Peridotite, with pyroxenite vein, Klamath Mountains, Northern California.

PeridotiteTRINITYPX

Peridotite (harzburgite) Kalamth Mountains Oregon.

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Mantle xenolith, closeup

Lherzolite (peridotite) xenolith (olivine, pyroxene) in basalt of Lorena Butte, Simcoe Volcanics, Washington, USA. Field of view is approx. 6 cm.

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Normal fault, near Vale, SE Oregon.

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Mount Shasta

Shasta and Shastina are among the youngest and most active of the Casacdes.

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Kolk pond. Near The Dalles, Oregon.

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Thrust fault, Hwy 97, 6 miles north of Madras, Oregon.

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NormalFaultnearPictureGorge

Angular unconformity

Angular unconformity, near Madras, Oregon. 7 million-year-old tuff was uplifted, then eroded, and river deposits accumulated as a flat layer atop the tilted beds.

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Slickensides

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Slickensides

SlickensidesRhyolite

Lateral Moraine and erratics, Wallowa Lake, Oregon.

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Pahoehoe, Jordan Craters, wih cinder cone in background.

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Rattlesnake Ignimbrite

Elongate, glassy clasts (Fiamme) are evidence of very high temperature deposition in an ignimbrite. Burns, Oregon

ignimbritewelded tuffRattlesnake tuff

Pillow Lavas

Pillow lavas, Marys Peak, Oregon coast range.

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Pillow Basalts and Palagonite

Pillow basalt in yellow clays (palognite), The Dalles, Oregon.

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