PaHoeHoe
Pahoehoe basalt, Jordan Craters, Oregon
pahoehoediamondcraterspx
Breccia
Volcanic breccia, Leslie Gulch (Owhyees) Oregon.
volcanicbrecciaredowyheesx
Scoria
Scoria. Tethero Butte cinder cone, Redmond, Oregon
scoriapx
Pumice
Pumice, From eruption of Mount Mazama, Oregon
pumice
Fossil alder leaf, Eocene Sandstone, Herren Formation, Pilot Rock, Oregon.
Eocleafdamage1
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.
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.
columnarbasalts4
Hexagonal (?) columns
Columnar jointing in basalt flow from Mount Adams, WA.
columnarjoints23
Columns and platy joints
Columnar jointing with horizontal platy joints. Near The Dalles, Oregon.
platycolumnsbasalt
Hackley Jointing
Pomona basalt flow, near Mosier, Oregon.
hackleyjointspomonaflow1
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.
basaltaphanitic
Platy jointing
Andesite, with platy joints and dis-organized columnar joints. Paradise, Mount Rainier, WA.
andesite
Porphyritic basalt
Steens basalt with large crystals (phenocrysts) of plagioclase, feldspar. Steens Mountain, Oregon.
steensbasalttexture
Flow-banded rhyolite
Flow banding in rhyolite. Pine Ridge, near Madras, Oregon.
bandedrhyoliteb
Mossy columns
Columnar jointing, Columbia River basalt flow, Rufus, Oregon
rufusbasaltcolumns2
Mt. Baker and its andesite
Platy jointing, andesite, Mount Baker, WA
bakerandesitetm1acrpa
Vesicular rhyolite
Gas holes (vesicles) in rhyolite, near Ashwood, Oregon.
rhyolitetubspringrd
Flow-banding
Flow-banding, rhyolite, Warm Springs, Oregon.
rhyolite
Cross-bedding
Closeup, X-bedding, pebble conglomerates and sandstones, Miocene Astoria Formation, Hug Point, Oregon
xbedshugpt1
Syncline
cretaceousfoldmitchell
Volcanic greenstone, Wallowa Mountains, Oregon.
GreenstoneWallowas
Volcanic mudflows, (Lahars) Clarno Unit, John day Fossil Beds National Monument, Oregon
CLARNOcliffs
Blueschist, Mitchell, Oregon
blueschist3
Closeup, blueschist, Mitchell, Oregon.
Gneissxtra
Pencil Shales, Izee, Oregon
IZEEterranepencilshales
Yellow Aster gneiss, North Cascades, Washingotn.
YellowAsterGneissA
Peridotite, with pyroxenite vein, Klamath Mountains, Northern California.
PeridotiteTRINITYPX
Peridotite (harzburgite) Kalamth Mountains Oregon.
VulcanHarzburgiteperidotite
Mantle xenolith, closeup
Lherzolite (peridotite) xenolith (olivine, pyroxene) in basalt of Lorena Butte, Simcoe Volcanics, Washington, USA. Field of view is approx. 6 cm.
mantlexenolith3
Normal fault, near Vale, SE Oregon.
BasinRangeFaultWeston
Mount Shasta
Shasta and Shastina are among the youngest and most active of the Casacdes.
shastashastina1
Kolk pond. Near The Dalles, Oregon.
KolkPondTheDalles
Thrust fault, Hwy 97, 6 miles north of Madras, Oregon.
ReversFaultHwy97X
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.
angularunconformity
Slickensides
slickensidesPx
SlickensidesRhyolite
Lateral Moraine and erratics, Wallowa Lake, Oregon.
WallowaLakeMorainesZx
Pahoehoe, Jordan Craters, wih cinder cone in background.
JordanCraters
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.
pillows
Pillow Basalts and Palagonite
Pillow basalt in yellow clays (palognite), The Dalles, Oregon.
pillowlavasthedalles