Martin Van Buren High School
Mr. Cesaire
Earth Science
Introduction to rocks
Aim: How do we classify rocks?
Do now (5-7 minutes)
• Define what is a rock. How are they formed in
the natural environment? What process can
change a rock’s appearance or composition?
• HW: Read pages 28-29 Answer 18-25 due
Wednesday.
• Mineral/Vocabulary quiz on Thursday
• www.tinyurl.com/8msdk <~~ updated
What is a rock?
• A rock can be defined as a natural piece of
the solid Earth, usually composed of one
or more minerals.
• Quite simply it’s a solid form of Earth
materials: Minerals, bits of broken rock,
and parts of once living organisms.
– An example of once living organisms turned
to rock: Coal
Origins of Rocks
Rock
Minerals
Ex: Quartz
Garnet
Pyroxene
Once Living Organisms
Ex: Fossils
Plants
Bits of Small Rocks
Limestone
Limestone (CaCO3) often formed near bodies
of water. Notice the fossils incorporated into the
rock.
Granite
Granite- an igneous rock that contains quartz, potassium feldspar, and biotite mica.
Usually formed by cooling deep within Earth.
Rock formation
o Rocks have three main methods of formation:
o Cooling of molten material
o Compaction and cementation
o Heat and pressure
o The methods if formation is similar to the
formation of minerals
Advancing lava
Lava is advancing down the road. Behind the lead edge the
lava has cooled and solidified.
Types of rocks
• Based on how they are formed, rocks are
categorized into three categories:
• Igneous
• Sedimentary
• Metamorphic
Basalt- Igneous
ConglomerateSedimentary
GneissMetamorphic
Let's Work Quickly!
• Aim: What are the distinguishing features
of igneous rocks?
• Do Now: Define the following terms from
the blue/orange text book
• Igneous Rock, mafic, felsic
HW #2 Read pages 54-57. Answer
questions 1-10
Quiz next Monday based on pages 54-57
Igneous Rocks
• Igneous rocks are molten mixture of
minerals and dissolved gases that have
cooled and crystallized.
• Molten material beneath the Earth’s
surface is called magma.
• Molten material above the Earth’s surface
is called lava.
Igneous Rocks
• Igneous rocks are typically described by
its texture.
• Texture refers to the minerals size, shape,
and arrangement of crystals or grains in a
rock.
• We will see examples of different textures
in our hand specimens.
• Open to page 121 to 122 of the text book
and answer the following questions in your
notes:
• 1. Describe the rate (how fast) magma cools.
What type of rock is formed?
• 2. Describe the texture of these rocks. Why
are the crystals larger?
• 3. Describe the rate (how fast) lava cools.
What type of rock is formed?
• 4. Describe the texture of these rocks. Why
are the crystals smaller
Intrusive Rocks-Extrusive Rocks
• Igneous rocks that form due to slow
cooling of magma are called Intrusive
rocks.
– Ex: Granite, Gabbro, Pegmatite
• Extrusive rocks cool rapidly above the
Earth’s surface
– Ex: Basalt, Rhyolite, Obsidian
Obsidian
Obsidian- lava has cooled so quickly that crystals were not
able to form. Obsidian has a glassy appearance.
In class activity
• You have a particular rock in front of you.
Briefly describe the rock’s size, shape,
color, grain size, mass (weight).
• Aim: How do we distinguish the
difference between igneous rocks?
• Do Now:
• HW: Read pages 54-57. Answer questions
1-10
• Quiz next Monday.
• Let’s watch a quick video on igneous
rocks.
Basalt
Mafic or Felsic?
Texture?
Intrusive or extrusive?
Granite
Mafic or Felsic?
Texture?
Intrusive or extrusive?
Pumice
Mafic or Felsic?
Texture?
Intrusive or extrusive
Scoria
Mafic or Felsic?
Texture?
Intrusive or extrusive
Obsidian
Mafic or Felsic?
Texture?
Intrusive or extrusive
• Aim: How do we identify igneous rocks?
• Do Now: Take out a piece of loose leaf
and prepare for your quiz on igneous
rocks.
• HW#3 Use page 16 of your Earth Science
Reference tables to fill out your crossword
puzzle.
• Quiz next Monday on Sedimentary Rocks.
QUIZ #2
• 1.How are igneous rocks formed? Where can
formation take place?
• 2. Explain the differences between magma and lava.
How does it relate to the grain size of an igneous
rock?
• 3. Define texture (for igneous rocks). Why do some
igneous rocks have larger grains (crystals) than
others?
• 4. Compare and contrast mafic and felsic rocks
BONUS How can we tell the difference between
intrusive and extrusive rocks?
• We need to use our knowledge of igneous
rock characteristics and page 6 of our
reference tables to identify igneous rocks.
• Let’s watch a video on how to properly use
the reference tables. Then we will identify
several igneous rocks.
• Video available at www.tinyurl.com/8msdk
• www.myspace.com/mrcesaire
• Aim: How can we describe the texture between
igneous rocks?
• Do Now: Open to page 30 of the green review book
and answer the following questions: #19, 21, 22, 23,
24, 25. It will be collected.
• HW: Read pages 59 to 62. This will be for your quiz
next Monday
• Quiz next Monday on Sedimentary Rocks./Project soon
• Latest videos and notes online:
www.tinyurl.com/8msdk,
www.myspace.com/mrcesaire
• Let’s watch a video the explains the
different types of textures if igneous rocks.
• http://www.classzone.com/books/earth_sci
ence/terc/content/investigations/es0603/es
0603page05.cfm?chapter_no=investigatio
n
• Based on the texture and mineral
composition, you have three families of
igneous rocks.
• 1. Granite Family
• 2. Gabbro Family
• 3. Diorite Family
• Answer the following questions based on
pages 123 to 124 of your text book.