Columbia River Flood Basalt Province, Idaho, Washington, Oregon, USA
View along the Imnahu River Canyon. Imnahu Basalt is overlain by Grande Ronde Basalt.
Imnahu River Canyon. Laterally extensive thick sheets of Imnahu Basalt overlain by Grande Ronde Basalt.
The Grande Ronde River cutting through the Grande Ronde Basalt. Note plateau at top right.
The Snake River in Hells Canyon. Flood lavas of the Columbia River Basalt Group overlie the rocks (light colored rocks in low areas) of the Wallowa accreted terrain.
The Roza flow with its pillow-plagonite complex near The Dalles, Oregon.
Tree cast is a flood basalt lava flow.
The Martindale flow is cut by a dike that feeds the overlying Goose Island flow. These flows are part of the Ice Harbor Member. Note the columnar jointing in the Martindale flow.
Dry Falls, a waterfall carved by glacial floods. The rim of the falls is four miles wide. The Interpretive Center at Dry Falls describes the geologic history of the area.
Palouse Falls formed during the catastrophic glacial floods that sculpted the Channel Scablands during the last Ice Age. Palouse Falls is 198 feet tall and is most spectacular in the spring and early summer. Palouse Falls is six miles above the Snake River.
Landsat image of the Channeled Scablands of eastern Washington.
VolcanoWorld wishes to thank Stephen Reidel for generously sharing his photographs of the Columbia River Flood Basalts.