The Geology of the Grand Canyon

Hannah Avery and Sarah Lowe

General Info about the Canyon

• Located in Northwestern Arizona

• Covers 1,218,375 acres of land

• Deepest point 6,000 feet

• Widest point 15 miles

How the Canyon Formed

• No one knows for sure but…– It is believed that…

• It is a combination of many things– Erosion (By water and ice)– Wind– Colorado River course– Volcanism– Continental Drift– Variations in Earth’s Orbit

Erosion by Water

• Located in desert so soil is less absorbent causing flash floods

• Flash floods can move automobiles, buses, and small houses– “If automobiles, buses, and small houses are in

the way then it will take them too.”

Erosion by Ice

• Water seeps into cracks and freezes, the freezing water expands, expanding the cracks.

• Expansion causes rocks to be pushed into the canyon causing Rock Falls

• Rock Falls often take out hiking trails

Layers of the Grand Canyon

Other Facts

• Roots of the ancient mountain range that lies at the base of the canyon was formed approximately 1.7 billion years ago

• Climate is considered semi-arid

• Colors are due to different amounts of minerals in the rocks

References

• http://www2.nature.nps.gov/geology/parks/grca/index.cfm

• http://www.kaibab.org/geology/gc_geol.htm#when

• http://en.wikipedia.org/wiki/Geology_of_the_Grand_Canyon_area

• http://www.pbs.org/wgbh/amex/canyon/sfeature/geology.html