How did Lava help form the Columbia Plateau?
Category:
science
geology
When pressure on the mantle is released as it is forced up through the crust due to subduction, it becomes basaltic magma. The Columbia River has eroded deep into the lava flows of the Columbia Plateau, revealing layers of columnar jointed basalt.
Moreover, how did the Columbia Plateau form?
The plateau formed between 6 million and 16 million years ago as the result of successive flows of basalt. Its northern border is marked by the Columbia River and the mouth of the Okanagon River. The Columbia River makes a looping S-curve through the central Washington part of the Columbia Plateau.
Thereof, how did volcanoes shape the Columbia Plateau?
As the molten rock came to the surface, the Earth's crust gradually sank into the space left by the rising lava. The subsidence of the crust produced a large, slightly depressed lava plateau. The ancient Columbia River was forced into its present course by the northwesterly advancing lava.
about 100,000 square miles