A Geological Marvel

Formed over the course of millions of years by water,

ice, wind, and tectonic activity, the Grand Canyon is a geological wonder.

The canyon is 277 miles long and up to 18 miles wide in some places. At a mile deep (over 5,000 feet), the Grand Canyon can be seen from space.

The huge variation in elevation between the canyon floor and the rim translates to a rich diversity of plant and animal life in and around the canyon.

Let’s explore how this natural wonder of the world

was formed.

When and how the Grand Canyon came to be is still the subject of some controversy in the scientific community.

There are two prevailing theories:

• The first suggests that the Colorado River carved most of the canyon over the last five to six million years.

• The second suggests that a series of ancient rivers flowing in the same general route eventually formed the giant

canyon we see today.

Another theory suggests that a giant lake covering eastern Arizona eroded through a limestone ridge, and the water that spilled through cut out the canyon over time.

One thing is certain: water has played a huge role in carving the Grand Canyon.

The Colorado River flows through the canyon, constantly eroding away the canyon walls.

When it rains, the hard, compacted earth in and around the canyon often cannot absorb much of the water, which then runs off of surfaces (often forming flash floods), loosening big boulders, dirt, and plant life.

This process of water erosion continues to shape the Grand Canyon today.

During the winter months, water seeps into the small cracks and crevices of rocks. Water expands when it freezes, causing the cracks in the rock to become larger (a process referred to as “frost heaving”).

Eventually, fragments of rock crack and split off. Fragments near the rim’s edge fall to the canyon floor and are washed into the Colorado River during flash floods. This frost heaving process contributes to erosion of the canyon.

Interesting fact: Glen Canyon Dam has significantly altered the erosive action of the Colorado River by greatly slowing down the flow of spring snowmelt.

Wind is yet another cause of erosion, especially in dry places like the Grand Canyon.

Wind picks up and carries away loose particles including dust, small rocks, and sand (a process referred to as “deflation”).

Wind can also contribute to erosion by causing flying particles to strike the land and break off more particles (referred to as “abrasion”).

Along with water and ice, wind erosion continues

to shape the Grand Canyon year after year.

The Earth’s crust is broken up into a series of approximately 20 “plates” that float on top of the planet’s mantle.

When two plates collide, they are forced together, causing them to buckle.

Over the course of millions of years, this buckling can lead to the formation of mountain ranges. This is how the Rocky and the Sierra Nevada mountain ranges in the United States were formed.

What do plate tectonics have to do with the Grand Canyon?

The short answer is that tectonic activity has helped shape the Grand Canyon over millions of years.

As one example, geologists know that most of the rock in the Grand Canyon is sedimentary, which is only formed under water. This tells them that climate cycles over the eons have caused the coastline to advance and retreat as far inland as the Grand Canyon, creating layers of sedimentary rock in which fossils are still found to this day.

Water, ice, wind, and tectonics have all converged to form the magnificent canyon we see today.

Whether you prefer a rugged experience like camping or backpacking, or a more relaxed excursion like a bus tour, there are plenty of ways to see the Grand Canyon.

A rafting adventure down the Colorado River immerses you in the depths of the canyon and is a great choice for families.

For an unparalleled birds-eye view, consider

a Grand Canyon helicopter tour!

Since 1965, Papillon has been the world's oldest and largest sightseeing company, flying an estimated 600,000 passengers a year on its daily tours to the Grand Canyon. With over forty unique excursions featuring spectacular sights of the Hoover Dam, Lake Mead, Monument Valley, Lake Powell, and

unforgettable views of the Grand Canyon, Papillon is proud to offer guests an unparalleled perspective of one of the world's greatest natural wonders.

Visit www.papillon.com for tour

information or call (888) 635-7272.