The Columbia Plateau in Washington and Oregon is ________.

Question

Question: The Columbia Plateau in Washington and Oregon is ________.

Options:

1.  a flood basalt plateau
2.  a thick stack of welded-tuff layers
3.  a caldera filled with rhyolite lava flow.
4.  a field of large stratovolcanoes

Answer 1

1.  A flood basalt plateau

The Columbia Plateau in Washington and Oregon is a flood basalt plateau.

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The Columbia Plateau is a geographical region located in across parts of the U.S. states of Washington, Oregon, and Idaho.

It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Columbia River.