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Chapter
14 Rock Cycle
Ch.
14: The
•Rock a naturally occurring solid mixture of one or
more minerals or organic matter.
•Rock Cycle- The Process by which new rock is
made by old rock
Chapter 14
Section 1 The Rock Cycle
Chapter 14
Section 1 The Rock Cycle
The Value of Rock
Ancient and modern civilizations have used rocks as
construction materials.
Rock is also an important ingredient in concrete and
plaster, used in todays construction
Section 1 The Rock Cycle
Chapter 14
Processes That Shape the Earth
• Weathering- process in which water, wind, ice,
and heat break down rock.
• Weathering is important because it breaks down
rock into fragments of which sedimentary rock is
made.
Chapter 14
Section 1 The Rock Cycle
• The process by which wind, water, ice, or gravity
transports soil and sediment from one location to
another is called erosion.
• The process in which sediment moved by erosion
is dropped and comes to rest is called deposition.
Break 14
!
Chapter
Chapter 14
Section 1 The Rock Cycle
• Heat and Pressure Sedimentary rock can also form
when buried sediment is squeezed by the weight of
overlaying layers of sediment.
• If the temperature and pressure are high enough, the
rock can change into metamorphic rock.
• If the rock gets hot enough to melt, this creates the
magma that eventually cools to form igneous rock.
Chapter 14
Section 1 The Rock Cycle
• How the Cycle Continues Buried rock is exposed
at the Earth’s surface by a combination of uplift and
erosion.
• Uplift is the movement within the Earth that causes
rocks inside the Earth to be moved to the surface.
• When uplifted rock reaches the Earth’s surface,
weathering, erosion, and deposition begin.
Chapter 14
Section 1 The Rock Cycle
• Composition is the chemical makeup of a rock.
Composition can describe either the minerals or
other materials in the rock.
• Texture is the quality of a rock that is based on the
sizes, shapes, and positions of the rock’s grains.
Chapter 14
Section 1 The Rock Cycle
Rock Classification
Rock can be three main classes based on how the
rock is formed:
Igneous rock
Metamorphic rock
Sedimentary rock
Chapter
14
Igneous
Rock
Section 2 Igneous Rock
• Igneous rock forms when hot, liquid rock, or
magma, cools and solidifies.
Chapter 14
Section 2 Igneous Rock
• When magma intrudes, or pushes, into surrounding
rock below the Earth’s surface and cools, the rock
that forms is called intrusive igneous rock.
• Intrusive igneous rock usually has a coarse-grained
texture because it is well insulated by surrounding
rocks and cools very slowly.
Chapter 14
Section 2 Igneous Rock
Chapter 14
Section 2 Igneous Rock
• Igneous rock that forms from magma that erupts, or
extrudes, on the Earth’s surface is called extrusive
igneous rock.
• Extrusive igneous rock, commonly found around
volcanoes, cools quickly on the surface and contains
very small crystals or no crystals.
Chapter 14
Section 3 Sedimentary Rock
Sedimentary Rock
• Wind, water, ice, sunlight, and gravity all cause rock
to physically weather into fragments.
• Through erosion, these rock and mineral fragments,
called sediment, are moved from one place to
another.
Break
Chapter
14
2!
Chapter 14
Section 3 Sedimentary Rock
• The most noticeable feature of sedimentary rock is
its layers, or strata.
• Stratification is the process in which sedimentary
rocks are arranged in layers.
Chapter 14
Section 3 Sedimentary Rock
Composition of Sedimentary Rock
Clastic sedimentary rock is made of fragments of
rocks cemented together by a mineral such as calcite
or quartz.
• Clasitc sedimentary rocks can have coarse-grained,
medium-grained, or fine-grained textures.
Chapter 14
Section 3 Sedimentary Rock
• Chemical sedimentary rock forms from solutions of
dissolved mineral and water.
• As rainwater slowly makes its way to the ocean, it
dissolves some of the rock material it passes through.
• Some of this dissolved material eventually
crystallized and forms the mineral that make up
chemical sedimentary rock.
Chapter 14
Section 3 Sedimentary Rock
• Organic sedimentary rock is made up of the
skeletons and shells of sea animals. These remains
collect on the ocean floor and eventually become
cemented together.
• Coal is a type of organic sedimentary rock that is
formed when decomposed plant material is buried
beneath sediment and is changed by increasing heat
and pressure.
Chapter 14
Break 3: Devils Tower
Chapter 14
Section 4 Metamorphic Rock
Metamorphic Rock
• Metamorphic rocks are rocks in which the structure,
texture, or composition of the rock have changed.
Chapter 14
Section 4 Metamorphic Rock
• Foliated Metamorphic Rock The texture of
metamorphic rock in which the mineral grains are
arranged in planes or band is called foliated.
• Foliated metamorphic rock usually contains aligned
grains of flat minerals, such as biotite mica or chlorite.
Chapter 14
Section 4 Metamorphic Rock
• Nonfoliated Metamorphic Rock The texture of
metamorphic rock in which the mineral grains are not
arranged in planes or band is called nonfoliated.
• Nonfoliated metamorphic rocks are commonly made of
one or only a few minerals.
• During metamorphism, crystals of these minerals may
change in size or the mineral may change in
composition in a process called recrystallization.
Chapter 14
Section 4 Metamorphic Rock
• Metamorphic rock has features that
indicates its history. These features are
caused by deformation.
• Deformation is a change in the shape of
a rock caused by a force placed on it.
• These forces may cause a rock to be
squeezed or stretched. Folds, or bends, in
metamorphic rock are structures that
indicate a rock has been deformed.