The Columbia Plateau in Washington and Oregon is ________.
A. a flood basalt plateau
B. a thick stack of welded-tuff layers
C. a caldera filled with rhyolite lava flow.
D. a field of large stratovolcanoes
Answer:A
The Columbia Plateau in Washington and Oregon is ________.
A. a flood basalt plateau B. a thick stack of welded-tuff layers C. a caldera filled with rhyolite lava flow. D. a field of large stratovolcanoes