Chapter 2 Review Fire and Ice Washington’s Geology

A Changing Land Explain the term Continental Drift Continents were joined together then drifted apart creating a narrow Atlantic Ocean. It widens three inches a year.

What causes landmasses to move and the earth to fold and crack? QUESTION… What causes landmasses to move and the earth to fold and crack? Tectonic forces, strong forces in the earth that cause landmasses to move and land ridges are forced upward.

Explain the term deluge, and how it affected Washington state? Deluge means heavy rain. For over 2,000 years, these floods came every 50 to 60 years creating the Columbia River to swell eroding the landscape.

COAL… What is coal, and why is it burned? Fossil fuel. Burned to provide heat to boil water making steam to run generators producing electricity.

Forming Our Mountains What are the oldest mountains in the west? Rocky Mountains The youngest are the Olympic Mountains. Before they became a mountain range what were they? They were once off-shore islands.

MOUNTAINS Name 3 of the 5 mountains that are considered the “sleeping giants”, and why are they called that? Mt. Baker, Glacier Peak, Mt. Rainier, Mt. Adams, and Mt. St. Helens. They are SLEEPNG GIANTS because they are dormant, temporarily inactive.

What is the ring of fire? Volcanoes in Indonesia, the Philippines, Japan, Alaska, and the west coast of North and South America. Within our state they are the Cascade and Olympic Mountains.

Name the mountain that most currently erupted in our state and what were the mudflows called? Mt. Saint Helens. Lahars: huge mud flows containing boulders, volcanic debris, and water.

Geologists believe what mountain to be Washington states most threatening volcano? Mt. Rainier

Forming the Columbia Plateau Repeated lava flows coming from what created the Columbia Plateau? Fissures: long cracks in the earth’s crust.

What is basalt and how is it formed? Igneous rock. Formed of hardened lava.

ANOTHER LANDSCAPE CHANGING EFFECT… Deposits of GLACIAL LOESS: these made rich soil; good for farming in Eastern Washington. A mixture of volcanic ash and dust carried by the wind.

Ice Age Washington During the last glacial period, the moving glaciers shaped the Puget Sound Lowlands. What are the huge boulders that were carried long distances by the glaciers called? Erratics

THE GREAT FLOODS What is another name for the Great Floods that is named after a geologist? THE BRETZ FLOODS: named after J. Harlen Bretz. He argued the case of the Spokane Flood.

THE GREAT FLOODS… Name three visible changes you can still see today that were caused by the great floods. erratics shape of the Puget Sound lowlands aquifers sculptured landscape of the Columbia Plateau Grand Coulee Dry Falls cataracts

Grand Coulee Name three geologic features of Grand Coulee. Many dry streambeds The largest prehistoric dry waterfall called DryFalls Cataracts (large waterfalls)

A STATE FOSSIL?? What is Washington’s official fossil? The Columbia Mammoth