Page 52 - Super Earth Encyclopedia

MULTICOLORED LAYERS

GRAND CANYON

One of the deepest river gorges in the world, the Grand Canyon
in the USA was created by the colossal forces that build mountains.
The South Rim of the
Over millions of years, they pushed up the rocks that form the canyon is 984 ft (300 m)
Colorado Plateau, forcing the Colorado River to cut down through them. lower than the North Rim.
The result is a spectacular canyon, displaying dramatic layers of rock.

Natural wonder
The main canyon of the Colorado River is
joined by side canyons cut by smaller streams,
forming a complex pattern. Scorching summer
heat and winter frost make the rock walls flake
and crumble, so the canyon slowly grows wider.

GRAND CANYON REVEALED
Layers of sand, mud, and other sediments
mainly laid down on the floor of a vanished
ocean have turned to beds of solid sedimentary
rock. The oldest lie at the bottom, above a layer
of ancient rock that was tilted, faulted, and worn
flat before the horizontal layers were deposited.

The Coconino
Sandstone formed
from sand dunes
275 million years ago.
Heavy rain in summer
feeds streams that flow
The 330-million- down the side canyons
year-old Redwall to join the river. One of the oldest layers,
Limestone forms the Vishnu Schist was
a sheer drop.
formed by heat and
pressure altering ancient
sedimentary rock.
A soft mudstone, the
Bright Angel Shale is
515 million years old.
AT A GLANCE

• LOCATION Arizona, USA
• LENGTH 277 miles (446 km)

• AVERAGE DEPTH 1 mile (1.6 km)
• AGE About 20 million years
The Vishnu
Schist is at least
1,730 million Faults in the tilted
years old. bedrock have
displaced the layers.

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