Download the rock cycle

What is the rock cycle?
The Rock Cycle
Chapter 4
Pages 90-111
What is the Rock Cycle?
Process in which:
1. A rock forms
2. A rock changes from one type to another
3. A rock forms again by processes on and
in the Earth.
Three Types of Rock

The three types of rock are:
1.
Sedimentary
Igneous
Metamorphic
2.
3.
Sedimentary Rock
Formed by:
• Weathering and Erosion of rocks into smaller
pieces or sediment.
• Deposition
• Compaction and Cementation
• Any rock (igneous, sedimentary, or
metamorphic) exposed at the Earth's surface
can become a sedimentary rock
Weathering and Erosion
Weathering:
BREAKDOWN of
rock by water,
constant heating and
cooling or other
natural causes, to
form sediment.
Erosion:
MOVEMENT of sediment
by wind and water
Deposition
• Streams and rivers transport sediment to
lakes or oceans, or deposit it on nearby
floodplains where it accumulates
Compaction and Cementation
• Over time these deposited grains and pieces of rock
are compacted and cemented together in layers.
• The compaction and cementation occurs when
sediment is squeezed by the weight of the sediment
layers above it.
• Each layer may be different from the next layer
depending on the type of sediment that is deposited.
• Fossils are often found in sedimentary rock.
Sedimentary Rocks
Breccia
Shale
Sandstone
Sedimentary Rock
.
•The remains of
plants and
animals
become
trapped in the
layers and over
long periods of
time and
become fossils.
Igneous Rock
• Igneous rocks (from the Greek word for fire)
form from hot molten rock (magma).
• The melt originates deep within the Earth near
active plate boundaries or hot spots, then rises
toward the surface.
• Igneous rocks are divided into two groups,
intrusive or extrusive, depending upon where the
molten rock solidifies.
• Where do you think INtrusive igneous rock
forms? Where do you think EXtrusive igneous
rock forms?
Extrusive Igneous Rock
• Extrusive igneous rock is produced when magma
exits and cools outside of, or very near the Earth's
surface.
• These are the rocks that form at erupting volcanoes
• The magma cools and solidifies almost instantly when
it is exposed to the cool temperature of the atmosphere.
• Cooling time determines rock fromed.
•Pumice-cooled quickly
•Obsidian-cooled
slowly
Black Sand Beach: Hawaii
• One of nature's rarest
wonders stretches across the
island of Hawaii's shores —
the black-sand beach of
Punalu'u. This magnificent
beach formed when lava from
two of the world's most active
volcanoes, Mauna Loa and
Kilauea, spilled into the ocean
and quickly cooled, breaking
into minuscule pieces that
now comprise the "sand."
Intrusive Igneous Rock
• Intrusive, or plutonic igneous rock forms when magma
is trapped deep inside the Earth.
• Great globs of molten rock rise toward the surface.
Some of the magma may feed volcanoes on the Earth's
surface, but most remains trapped below, where it cools
very slowly over many thousands or millions of
years until it solidifies.
• Intrusive igneous rock can be pushed to the surface by
plate movement.
•
Granite is a type of intrusive igneous rock.
Metamorphic Rock
• Metamorphic rocks are
rocks that have "morphed“,
or changed into another
kind of rock.
• These rocks were once
igneous or sedimentary
rocks.
• How do sedimentary and
igneous rocks change?
• When large pieces of crust
collide (convergent
boundary, subduction
zone), rock is forced
downward.
• Heat and pressure squeeze
the sedimentary or igneous
rock and change it into
metamorphic rock.
Metamorphic Rock
•Shale, a sedimentary rock, is
changed by heat and pressure
into slate
S: shale
•Limestone, a sedimentary rock,
is changed by heat and pressure
into marble. Marble is used to
make statues and countertops.
S: Limestone
M: slate
M: Marble
THE ROCK CYCLE
The Rock Cycle
Review
• Name the 3 types of rock.
• This process causes rock to break down into smaller pieces called
sediment.____________________________
• This action carries sediments to rivers and lakes._______________
• Sedimentary rock is formed by _________________and
______________.
• Igneous rock is formed from_______________________________.
• Two types of igneous rock______________ and ______________.
• What causes sedimentary and igneous rock to become
metamorphic rock?
__________and___________
• Intrusive igneous rock forms_________________________
• Extrusive igneous rock forms_____________________________
• Can any rock become a sedimentary rock?__________________
• Which type of rock would contain fossils?_____________________