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Earth’s History
Chapter 4 Lesson 1
Objectives
• List 5 categories of mountains and describe how each type of mountain forms.
• Identify major California mountain ranges on a relief map.
Main Idea
• Mountains _______________from _______________ _______________.
Vocabulary
• _________________________ – (noun), a mountain range formed by magma that escaped
from Earth’s interior, then cooled.
• _________________________ – (noun), a block of crust that is pushed upward along a fault.
• _________________________ – (noun), area where a magma plume rises in the mantle and
erupts through a plate.
• _________________________ – (noun), a dome-shaped mound that forms in Earth’s crust
from magma that rises but does not break through.
• _________________________ – (noun), a folded piece of crust formed where continental
plates collide.
Building Background
A mountains form primarily at the boundaries of _______________, due to the motions that deform
the crust or bring magma from the Earth’s interior to the surface.
Folding and Faulting Forces
• ____________________ are Earth’s tallest landforms. Because mountains are so huge you
may think they are _______________. But that is not _______________. Mountains are
continually being ____________________ or ____________________. The actions of
____________________ ____________________ build up mountains, while
____________________ and ____________________ wear them down.
• Most ____________________ form near plate boundaries, especially where two
_______________ push together. In these zones, _______________ ____________________
are common.
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• Over time, _______________wears down and softens the _______________. That is why
some mountains have _______________ peaks. In other cases, stress on the crust causes it
to _______________ instead of _______________. This creates _______________, or
_______________, in the crust. _______________ ____________________ may form
wherever faulting occurs. This type of mountain forms from a block of _______________ that
is pushed ____________________ or ____________________ along a fault.
• In most cases, ____________________ ____________________ form when stress splits the
crust. Land on one side of the _______________ is raised, while the other side drops
____________________.
• As with _______________ ____________________, erosion helps shape
____________________ _____________________. _______________ mountains have softer
edges. Many valleys near the ____________________ are partly filled with material that has
_______________ from nearby mountainsides.
• California’s Death Valley is a block of land that has dropped between _______________
_______________. It dropped so far that _______________ _______________ is the lowest
point in the United States.
• What are the 5 categories into which mountains are classified?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Volcanic Forces
• Volcanic activity often happens at ____________________ ____________________, when the
edge of one plate _______________ _______________ another. The edge of the sinking
plate melts into _______________ deep underground. If it bursts through the
_______________, it can build up over time to form a ____________________
____________________.
• At ____________________ ____________________, magma rises up in the gap between the
two plates that are pulling apart. Recall that _______________ _______________ form in
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this way at divergent boundaries on the ocean floor. The buildup of cooled magma under
the sea has created the world’s longest _______________ _______________.
• Volcanic mountains can form away from _______________ _______________ as well. Magma
plumes rising from the _______________ create _______________ _______________ under
some areas of the crust. As a plate moves over a hot spot, _______________
_______________ can erupt through the plate, creating ____________________
____________________.
• Sometimes, _______________ rises toward the surface but doesn’t break through the
_______________. It may push up _______________, creating a _______________
_______________.
• What are the steps in the formation of a mid-ocean ridge?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Erosion Mountains
• Weathering and _______________ continually shape Earth’s ____________________.
Although mountains can be affected by these forces, a few _______________ were formed
entirely by them. These are called _______________ ____________________. The
_______________ in New York State are one example. The Catskills were once a
_______________, or raised area of flat land. Mountains began forming during the last
_______________ _______________, when glaciers carved the plateau into peaks and
valleys. Later, _______________ _______________ further sculpted the land.
• Erosion has shaped other kinds of _______________ after they formed originally. The results
are _______________ _______________ and valleys. California’s largest mountain, range
the _______________ _______________, was also shaped by _______________. Glaciers
shaped some of the _______________ and _______________ out bowls, now filled with small
lakes. _______________ also widened V-shaped mountain valleys into _______________
_______________ now seen in parts of the Sierras.
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• How are dome mountains different from most other mountains?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
California Mountains
• Most of California is on the _______________ ____________________ _______________.
Some of western California is on the _______________ _______________. The movements of
these plates have helped _______________ the mountains of California.
• The Sierra Nevada chain is a huge range of ____________________ ____________________.
The mountains are a block of _______________ tilted _______________ from a fault that
runs along their edge.
• Other mountain ranges in California are the result of _______________ forces that
_______________ and _______________ Earth’s crust. _______________ mountains form as
a result. About 30 million years ago, the interaction between the _______________ and
_______________ ____________________ _______________ pushed up the _______________
_______________. These include the _______________ and _______________
_______________ ____________________. As the plates slipped past each other, the ocean
floor _______________ and _______________ to form the mountains.
• Mount Shasta and _______________ _______________ are _______________ mountains that
are part of the Cascades. The Cascade Range is a chain of _______________, formed where
several smaller tectonic plates are _______________ beneath the North American Plate.
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