Rocks of Earth
Metamorphic Rock: Gnesis
Sedimentary Rock: Sandstone
Igneous Rock: Granite
How Rocks are Formed: Igneous
Rocks
Lava: liquid rock found above ground
Magma: liquid rock found underground
Rocks are formed by cooling of Magma underground or from lava above ground.
Rocks formed by the cooling of magma or lava are known as Igneous Rocks.
Granite is an igneous rock formed from cooling of magma. Basalt is an igneous
rock formed from cooling of lava
How Rocks Are Formed: Sedimentary
Rocks
Types of sedimentary rocks Sandstone,
Shale, and Limestone.
• Sedimentary rocks are
created by rocks being
broken down into small
particles or fragments
called sediments.
When sediments are
deposits and
compressed, cemented
together, and harden
forming sedimentary
rocks.
How Rocks are Formed: Metamorphic
rocks.
• Metamorphic rocks are
formed by parent rocks
under extreme heat,
pressure or chemical
processes change the
form of rock.
Metamorphic rock
means changed form.
• Slate, Schist, and Gneiss
are examples of a
metamorphic rock
The Rock Cycle
Rock Cycle Worksheet
Rock Questions
1. How are igneous rocks formed? Give
example of two types of igneous rocks.
2. How are sedimentary rocks formed? Give
example of three types of sedimentary rocks
3. How are metamorphic rocks formed? Give
example of three types of metamorphic rocks
4. Explain the rock cycle
Igneous Rocks: Texture
• Intrusive Igneous Rocks:
• Rocks formed by
magma cooling slowing
beneath Earth’s surface
over a long period of
time.
• Intrusive Igneous rocks
are coarse grained rocks
• Granite is an example of
intrusive rock
• Extrusive Igneous Rocks
• Rocks formed from
cooling of lava on the
Earth’s surface.
• Extrusive igneous rocks
are fine grained rocks.
• Basalt is an example of
a extrusive igneous rock
Igneous Rock: Composition
• Felsic Rocks are formed
from magma that
contains a large amount
of silica.
• Felsic rocks are light in
coloring due to the
mineral composition of
feldspar and quartz
• Granite is an example of
a felsic igneous rock
Granite is coarse grain and quartz or silica
is the sparkle found in the rock. This gives
the rock a light color.
Igneous Rock: Mafic
• Mafic igneous rocks
contain less silica than
felsic rocks.
• Mafic rocks are dark in
color because of the
iron and/or magnesium
• Basalt is an example of
a mafic rock
Basalt is a dark color mafic rock. It is a
fine grain rock.
Igneous Rocks: Intermediate
• Intermediate rocks are
rocks that have less
silica than a felsic rock,
but more silica than a
mafic rock.
• Diorite is an example of
an intermediate
igneous rock.
Diorite is an intermediate igneous rock.
There is dark and light minerals found in
this rock.
Igneous Rocks Question
1. What is an intrusive Igneous rock give an
example
2. What is an extrusive Igneous rock give an
example
3. What is a felsic igneous rock give an example
4. What is a mafic igneous rock give an example
5. What is an intermediate igneous rock give an
example.
Igneous Rock Questions
6. What is the relationship between an intrusive
igneous rock and a felsic igneous rock.
7. What is the relationship between an extrusive
igneous rock and a mafic igneous rock.
8. Both Granite and Basalt are igneous rocks, but
they are very different types of igneous rocks
create a T-chart showing the difference
between the two rocks.
Sedimentary Rocks
• Sedimentary rocks are
formed from particles
of rocks that have been
broken down by wind
and water. When the
little pieces are broken
from the rocks, they are
washed downstream
and settle in the bottom
of streams, rivers, and
oceans.
Sandstone
Shale
Limestone
Formation of Sedimentary Rocks
•Compaction and cementation are the two ways
sedimentary rocks are created.
•Sedimentary rocks are classified by the processes
by which the rocks are formed and by the
composition of the rock
• There are three main classes of Sedimentary
Rocks: Chemical, Organic, and Clastic.
Chemical and Organic Sedimentary
Rocks
• Chemical sedimentary
• Organic Sedimentary
rocks are formed from
Rocks are formed from
minerals that were once
the remains of living
dissolved in the water.
things. As sea animals
die the shells and bones
• When water evaporates
are deposited on the
the minerals dissolved
ocean floor.
in the water are left
behind.
• Limestone is an
example.
• Rock salt is an example.
Clastic Sedimentary Rocks
•Clastic Sedimentary rocks are formed from
rock fragments that are carried away from
the source by wind, water, or ice.
•The particles are deposited at the bottom
of rivers or oceans.
•Over time the fragments are compacted
and cemented to other rock fragments
forming a sedimentary rock.
Clastic Sedimentary Rocks
• The sedimentary rocks
are classified by the size
of the fragments found
in the rock.
• A conglomerate
sedimentary rock has
large particles.
• A sandstone is made of
sand-sized grains that
have been cemented
together.
• Quartz is a major
component of
sandstone because it is
such a hard mineral
Clastic Sedimentary Rocks
• A third group of clastic sedimentary rock is
shale that has clay size grains or very fine
grained rock.
• Shale is compacted into flat layers that will
easily split apart.
Where are Sedimentary Rocks
Formed
• Where sedimentary rocks are formed depends
on the size of the particles. Through sorting
the larger grained rocks are formed near
shoreline or at the mouth of rivers. The larger
particles will settle first. (Conglomerates)
• Along the beaches and near shore sand-size
particles settle out of the water and are
deposited (sandstone)
Where are Sedimentary Rocks
Formed
• The finer grained particles stay suspended in the
water longer therefore are deposited farther out
from the shore where the water’s movement has
slowed down. (Shale)
• The area by the continental shelf where coral
reefs and much of the plant and animal life of the
ocean is found is the last place for sedimentary
rocks to form. The rocks are formed from the
shells and skeletons of dead marine life.
(Limestone)
Questions on Sedimentary Rocks
1. How is a sedimentary rock formed?
2. What are two ways a sedimentary rock is
created?
3. What are 3 classifications of sedimentary
rocks?
4. How are chemical sedimentary rocks formed
and give an example of a chemical
sedimentary rock.
5. How are organic sedimentary rocks formed
and give an example of a chemical
sedimentary rock.
6. What are the 3 types of Clastic sedimentary
rocks. Describe the difference between each
one and give an example.
7. Draw the diagram explaining where each of
the sedimentary rocks would be deposited.
Explain what the diagram is showing.
Metamorphic Rocks
Metamorphic Rocks
• Metamorphism is the alteration of a
preexisting rock (the parent rock) due to heat
and pressure caused by burial in the earth.
• The parent rock must adapt to the new
conditions and it does so by changing mineral
composition and texture. These rocks with
new texture and composition are
metamorphic rocks.
Facts about Metamorphic Rocks
•
Classified by texture and composition
May react with acid
• May have alternate bands of light and dark
minerals
• May have layers of visible crystals
Facts about Metamorphic Rocks
• May be composed of only one mineral, ex.
marble & quartzite
• Usually made of mineral crystals of different
sizes
• Rarely has pores or openings
• May have bent or curved foliation
Regional Metamorphism
• Regional metamorphism takes place during
mountain building events when very large areas of
sedimentary rocks are buried, squeezed, and heated.
• metamorphic rocks not only tell us the kind of
metamorphism, they are also a measure of the
intensity of metamorphism. The closer we get to the
source of heat and pressure the more altered the
rock becomes.
Contact Metamorphism
• Contact metamorphism occurs in the "
country rock" (the rock intruded by and
surrounding an igneous intrusion). Rocks are "
baked" into a ceramic from heat escaping
from intrusives, often enhanced by hot fluids.
Foliated Metamorphic Rocks
• The metamorphic texture in which minerals are
arranged in planes or bands.
• Foliated rocks formed in one of two ways
• Extreme pressure may cause the mineral crystals in
the rock to realign or re-grow to form parallel bands.
• Minerals that have different composition separate
and produce a series of alternating dark and light
bands
• Examples Slate and Gneiss
Non-foliated Metamorphic Rocks
• Metamorphic rocks that do not have bands or
aligned minerals.
• The parent rock may contain grains from only
one mineral
• The grains of the parent rock may be round or
square therefore it does not change direction
when exposed to pressure in one direction
• Example Quartzite and Marble
Foliated/Nonfoliated Metamorphic Rock
• Foliated Rocks
• Complex composition,
many different kinds of
minerals.
• Many new minerals
produced with a change
in Temp. and/or Pres.
• Non-foliated Rocks
• Simple composition,
only a few minerals
such as calcite or
quartz.
• No new minerals form
with a change in Temp
and/or Pres.
Foliated/Nonfoliated Metamorphic Rocks
• Texture is layered,
foliated, lineated,
banded. Minerals have
a preferred orientation
• Many rocks with diverse
compositions
• Texture is granular and
No preferred
orientation
• Few rocks with simple
compositions.
Qtz SS - Quartzite
Limestone - Marble
Dolostone - Dolomitic
Marble
Shale - Hornfels
Metamorphic Rock Table
Metamorphic Rocks and Parent Rock
• Quartz Sandstone becomes Quartzite, nonfoliated
• Limestone: becomes Marble, non- foliated.
• Shale: becomes slate, to schist, to gneiss
• Foliated metamorphic rocks