The Columbia Plateau, also known as the Columbia Basin, is the site of one of the largest outpourings of lava that the world has ever seen . The Columbia Plateau flood basalts are a notable example of a “Large Igneous Province,” where vast volumes of basalt are erupted over a relatively short period of time.
What crops are grown in the Columbia Plateau?
alfalfa, fruit, potatoes, and vege- tables . Some alfalfa and fruit is also grown without irrigation in the sub- humid portions of the region, but characteristically the Columbia Pla- teau is a region of dry-land wheat, grown on large farms and seeded and harvested by large-scale machinery.
Why is the Columbia River Plateau so flat?
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.
Why is it called the Columbia Plateau?
It is named for the Columbia River Plateau, a flood basalt plateau formed by the Columbia River Basalt Group during the late Miocene and early Pliocene . ... The underlying basalt is up to 2 miles (3 km) thick and partially covered by thick loess deposits.
Is the Columbia Plateau a lava plateau?
Over 170,000 cubic kilometers (105,633 mi) of basaltic lava, known as the Columbia River Basalts, covers the western part of the province. They found that the youngest rocks were grouped around the Yellowstone plateau, with lavas increasing in age to the west. ...
Why is the Columbia Plateau so dry?
The Columbia Plateau is mostly covered by grasslands and some forests, and is composed primarily of Mollisols. These soils tend to be dry in the summer and are later re-moistened by the fall and winter rains.
What are the 5 main composite volcanoes that pose hazards to those living in Washington?
Washington has five volcanoes that are listed as high or very high threat potential: Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams .
How tall is the Columbia Plateau?
It is a roughly triangular-shaped area about 250 miles on a side. On its fringes the elevation of the plateau is about 4,000 feet (1,219 meters) above sea level , and at its lowest point it is about 400 feet (122 meters).
Is the Columbia Plateau a desert?
In this semi- arid land it is instructive to be reminded that the ecoregion’s fisheries are an important part of its diversity. ... The fisheries in those portions of the ecoregion not in the Columbia River basin are made up of numerous isolated desert fishes that are threatened throughout the ecoregion.
What are some important natural resources of the Columbia Plateau?
The primary mineral resources found in the Columbia Plateau are glacial deposits of sand, gravel, and stone . These are used as building materials, and are also shipped outside the region for use elsewhere.
Are plateaus volcanic?
A plateau is a flat, elevated landform that rises sharply above the surrounding area on at least one side. ... A volcanic plateau is formed by numerous small volcanic eruptions that slowly build up over time, forming a plateau from the resulting lava flows.
Which plateau is in North America?
A large plateau in North America is the Colorado Plateau , which covers about 337,000 km 2 (130,000 sq mi) in Colorado, Utah, Arizona and New Mexico. In northern Arizona and southern Utah the Colorado Plateau is bisected by the Colorado River and the Grand Canyon.
How does the rain shadow effect impact the Columbia Plateau?
The Cascade Mountains cast a long rain shadow over the Columbia Plateau. In the state’s semi-arid interior, summers are hot and dry and winters are cold and gray. Precipitation occurs mainly between late fall and early spring.
What is the Columbia River Plateau an example of?
The Columbia Plateau, also known as the Columbia Basin, is the site of one of the largest outpourings of lava that the world has ever seen. The Columbia Plateau flood basalts are a notable example of a “Large Igneous Province ,” where vast volumes of basalt are erupted over a relatively short period of time.
What type of volcano has the largest and most violent eruptions?
Stratovolcanoes are considered the most violent. Mount St. Helens, in Washington state, is a stratovolcano that erupted on May 18, 1980.
Which kind of eruptive activity is highly explosive?
| Question Answer | Which kind of eruptive activity is most likely to be highly explosive? eruptions of big, continental margin, composite cones or stratovolcanoes | Magma tends to rise toward Earth’s surface principally because ________. rocks become less dense when they melt |
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