Topic of Lesson:Igneous Rocks
Approximate Time: 1 ½ - 2 class periods
Materials/Equipment Needed: Objectives:
Igneous Rock Power Point Presentation (available for free)
Blank Student Volcano Diagram Identifying Igneous Rocks Lab Igneous Rock Identification Flow
Chart Numbered rock samples for each
group:(gabbro, diorite, pegmatite, granite, pumice, scoria, obsidian, basalt, and rhyolite)* 1 hand lens/magnifying glass
(minimum) per group 1 container of water (large enough
to hold the biggest rock sample) per group
1 metric ruler (minimum) per group
*If you only have some of the rock samples, the lab can still be done, but it will take less time with fewer rocks. If you do not have enough rock samples for each group, you can always have them rotate to different “stations” in the room, each with a different set of rocks.
Students will be able to:
Explain how an igneous rock forms.
Give the two main types of igneous rocks and explain their differences.
Determine if samples of igneous rocks are intrusive or extrusive, mafic, felsic, or intermediate, and then provide the general grain size.
Identify the name of various igneous rocks using the characteristics of igneous rocks and a flow chart.
Using the characteristics of igneous rocks, students will be able to determine how the rocks formed and the general composition of the magma/lava that formed individual rocks.
Context Within Unit: Rationale/Purpose:This is an introduction to igneous rocks. Students will become familiar with the characteristics of igneous rocks and the two main types. Ideally crystal formation and minerals should have been learned in lessons prior to this one; however, this lesson can still be carried out successfully without previous information on minerals or crystals.
Students will have the opportunity to practice using the characteristics of igneous rocks to identify the names of samples of Igneous rocks.
Differentiated Instruction (ELL, special needs):Copies of Igneous Rock notes should be provided for Level 1 & 2. Igneous Rock note sheet is differentiated for Levels 3 & 4Identifying Igneous Rocks Lab is differentiated for Level 1/2 and Level 3
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Anticipatory Set “Bell Ringer”*Day 1: In their notebooks, students answer the following question and make a quick sketch: The Latin word, ignis, is similar to the English word, ignite. What comes to mind when you hear the word ignis or ignite? Draw a picture of ignite.
*Bell Ringers Template available for free. Day 2: Students take out their closure and notes from yesterday and find 5 more facts about igneous rocks that they did not include on their closure from the previous day.
Instruction:Day 1:
1. With a partner or in groups, have students share their answers and drawings to the bell ringer question.
2. Power Point Presentation with student note sheet3. Go over directions for Identifying Igneous Rocks Lab and do one sample as a class4. If time students can start working on the lab
Day 2: 1. Students share their facts from the bell ringer in a whole group setting. 2. Remind students of your expectations for the Igneous Rock Lab
PracticeDay 1: Students begin working on the Identifying Igneous Rocks Lab
Day 2: 1. Students complete Identifying Igneous Rocks Lab2. Students answer Key Questions from the lab3. Go over/discuss key questions with students either at the end of the period or the
next day. Questions: New Vocabulary:
How do Igneous rocks form?
What are the 2 main types of Igneous rocks?
What are the differences between an intrusive and extrusive rock?
How can you tell if an igneous rock is intrusive or extrusive just by looking at it?
What can the appearance of an igneous rock tell you about how it formed?
Igneous Rock Intrusive Extrusive Mafic Felsic Vesicular Texture
© 2011 ACQUIRE Lesson Plans
Why can’t both intrusive and extrusive rocks both have a vesicular texture?
What can the color of an igneous rock tell you?
What 2 things determine what kind of igneous rock forms?
Closure:(About 5 minutes)*
Assessment:
Day 1: In their notebooks, students list 2 facts about igneous rocks and then share with a partner. If their partner wrote a fact that they did not then they should add it to their list.
Day 2: On scratch paper or on “Do Know/Don’t Know” slip* students write one thing they know/understand and one thing they don’t know/understand or one question they have.
*Closure Templates available for free
Bellringer and Closure answers
Answers to Key Questions on Igneous Rock Lab
Identification of Igneous rocks in the lab.
© 2011 ACQUIRE Lesson Plans
Igneous comes from the Latin word, ____________________, meaning ___________________.
Igneous rocks are rocks that form __________________________________________________________________________________________________________
Lava vs. Magma
Lava: __________________________________________________________________________________________________________________________________________
Magma: _______________________________________________________________________________________________________________________________________
Magma Composition
•Type of igneous rock that forms depends ___________________________________________________________________________________________
•Magma is often a ___________________________________________________________________________________________________________________________.
•Common elements in magma: _________________, _________________, ___________________, ______________, ________________, calcium,
potassium, and sodium.
•___________________(SiO2) is the most abundant & has the _________________________________________________________________________________
________________________________________________________________.
It affects _________________________________________ & how ________________________________________________________________________________.
Classification of Igneous Rocks
1. ________________________________: magma cools & crystallize________________ Earth’s surface.
-Crystals are generally
________________________________________________________________________________________________.
© 2011 ACQUIRE Lesson Plans
Igneous Rocks Note Sheet Level 5
Draw a picture for Intrusive Igneous Rock
Draw a picture for Vesicular Texture
2. ________________________________: magma that cools and crystallizes ___________________
Earth’s surface
-Crystals that form in these rocks are
__________________________________________________________________________________________.
Texture of Igneous Rocks
Texture refers to the ____________________________________________________________________________________________________________________ that make up a rock.
Crystal Size & Cooling Rates:
When lava flows on Earth’s surface, it cools ________________________ & there is ________________________________________________
for _______________________crystals to form.
Sometimes cooling occurs so ___________________that crystals _____________________________________________________. The result is volcanic glass (ex. obsidian).
When magma cools ___________________________beneath Earth’s surface, there is _______________________________________________
for ________________________crystals to form.
Vesicular Texture
•______________________________ appearance (ex. Pumice)
•Magma contains dissolved gases that escape; however, __________________________cooled
lava contains ______________________________. When the lava hardens, the ___________________
(or _______________________) that remain are from the previously trapped air bubbles.
© 2011 ACQUIRE Lesson Plans
Draw a picture for Extrusive Igneous Rock
Igneous comes from the Latin word, ____________________, meaning ___________________.
Igneous rocks are rocks that form __________________________________________________________________________________________________________
Lava vs. Magma
Lava: __________________________________________________________________________________________________________________________________________
Magma: _______________________________________________________________________________________________________________________________________
Magma Composition
•Type of igneous rock that forms depends ___________________________________________________________________________________________
•Magma is often a slushy mix of ___________________________________________________________________________________________________________.
•Common elements in magma: _________________, _________________, Aluminum, ______________, Magnesium, calcium, potassium, and
sodium.
•Silica (SiO2) is the most abundant & has the most effect on ________________________________________________________________________.
It affects _________________________________________ & how ________________________________________________________________________________.
Classification of Igneous Rocks
1. ________________________________: magma cools & crystallize________________ Earth’s surface.
-Crystals are generally
________________________________________________________________________________________________.
© 2011 ACQUIRE Lesson Plans
Igneous Rocks Note Sheet Level 4
Draw a picture for Intrusive Igneous Rock
Draw a picture for Vesicular Texture
2. ________________________________: magma that cools and crystallizes ___________________ Earth’s
surface
-Crystals that form in these rocks are
__________________________________________________________________________________________.
Texture of Igneous Rocks
Texture refers to the _____________, _______________, & _____________________________of the crystals or grains that make up a rock.
Crystal Size & Cooling Rates:
When lava flows on Earth’s surface, it cools ________________________ & there is ________________________________________________
for _______________________crystals to form.
Sometimes cooling occurs so ___________________that crystals _____________________________________________________. The result is volcanic glass (ex. obsidian).
When magma cools ___________________________beneath Earth’s surface, there is
enough (sufficient) time for ________________________crystals to form.
Vesicular Texture
•______________________________ appearance (ex. Pumice)
•Magma contains dissolved gases that escape; however, __________________________cooled
lava contains ______________________________. When the lava hardens, the ___________________ (or
_______________________) that remain are from the previously trapped air bubbles.
© 2011 ACQUIRE Lesson Plans
Draw a picture for Extrusive Igneous Rock
Igneous comes from the Latin word, ____________________, meaning ___________________.
Igneous rocks are rocks that form when _________________________(Lava or Magma) _______________ and crystallizes.
Lava vs. Magma
Lava: molten rock that flows out _________________ Earth’s ______________________.
Magma: molten rock _____________________ Earth’s surface
Magma Composition
•Type of igneous rock that forms depends on _________________________ of magma (What the magma is made of).
•Magma is often a slushy mix of molten ________________, dissolved ____________________, and mineral _____________________. •Common elements in magma: _________________, _________________, aluminum, iron, magnesium, calcium, potassium, and sodium.
•Silica (SiO2) is the most abundant & has the most effect on magma ___________________________________.
It affects _______________temperature & how __________________it flows.
Classification of Igneous Rocks
1. ________________________________: magma cools & crystallize________________ Earth’s surface.
-Crystals are generally large enough to see without magnification
© 2011 ACQUIRE Lesson Plans
Igneous Rocks Note Sheet Level 3
Draw a picture for Intrusive Igneous Rock
Draw a picture for Vesicular Texture
2. . ________________________________: magma that cools and crystallizes ___________________ Earth’s
surface
-Crystals that form in these rocks are small & difficult to see without magnification
Texture of Igneous Rocks
Texture refers to the _____________, _______________, & _____________________________of the crystals or grains that make up a rock.
Crystal Size & Cooling Rates:
When lava flows on Earth’s surface, it cools ________________________ & there is not enough time for
_______________________crystals to form.
Sometimes cooling occurs so ___________________that crystals ________________________ form. The result is volcanic glass (ex. obsidian).
When magma cools ___________________________beneath Earth’s surface, there is enough (sufficient) time
for ________________________crystals to form.
Vesicular Texture
•______________________________ appearance (ex. Pumice)
•Magma contains dissolved gases that escape; however, ___________________cooled lava
contains _________________gases.
When the lava hardens, the ___________________ (or vesicles) that remain are from the
previously trapped air bubbles.
© 2011 ACQUIRE Lesson Plans
Draw a picture for Extrusive Igneous Rock
Igneous comes from the Latin word, ignis, meaning fire.
Igneous rocks are rocks that form when molten material (Lava or Magma) cools and crystallizes.
Lava vs. Magma
Lava: molten rock that flows out onto Earth’s surface.
Magma: molten rock below Earth’s surface
Magma Composition
•Type of igneous rock that forms depends on what the magma is made of.
•Magma is often a slushy mix of molten (melted) rock , dissolved gases and mineral crystals. •Common elements in magma: Oxygen, Silica aluminum, iron, magnesium, calcium, potassium, and sodium.
•Silica (SiO2) is the most abundant & affects melting temperature & how fast it flows.
2 Main Types of Igneous Rocks
1. Intrusive Igneous Rock : magma cools & crystallize below Earth’s surface.
-Crystals are generally large enough to see without magnification
© 2011 ACQUIRE Lesson Plans
Igneous Rocks Notes Level 1 & 2
Draw a picture for Intrusive Igneous Rock
Draw a picture for Vesicular Texture
2. Extrusive Igneous Rock : magma that cools and crystallizes on Earth’s surface
-Crystals that form in these rocks are small & difficult to see without magnification
Texture of Igneous Rocks
Texture refers to the size, shape, & distribution of the crystals or grains that make up a rock.
Crystal Size & Cooling Rates:
When lava flows on Earth’s surface, it cools fast & so only small crystals to form.
Sometimes cooling occurs so fast that crystals no crystals form. The result is volcanic glass (ex. obsidian).
When magma cools slowly beneath Earth’s surface, there is enough time
for large crystals to form.
Vesicular Texture
•Spongy appearance (ex. Pumice)
•Magma contains dissolved gases that escape; however, quickly cooled lava contains
trapped gases.
When the lava hardens, the spaces or holes (or vesicles) that remain are from the
previously trapped air bubbles.
© 2011 ACQUIRE Lesson Plans
Draw a picture for Extrusive Igneous Rock
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Name: ____________________________________ Date: ________________________ Period: _____Levels 4 & up
“Identifying Igneous Rocks” LabBackground:
Igneous rocks are formed when molten rock cools and hardens. There are two main types of igneous rock: intrusive (magma hardens below earth’s surface) and extrusive (lava hardens on earth’s surface). When magma cools atoms arrange in a repeating pattern to form crystals. Slow cooling magma produces large crystals. Faster cooling lava produces small crystals. Sometimes lava cools so fast that it hardens (freezes) before any crystals can from. In this case, volcanic glass is created.
The color of the igneous rock (light or dark) is based on the chemical composition of the magma. Mafic igneous rocks are darkly colored due to high composition of iron and magnesium. Felsic igneous rocks are lightly colored due to low composition of iron and magnesium and a high silica (SiO4) content. Some are neither mafic nor felsic. They are “in-between” in composition and thus color. Rocks such as these are called intermediate.
Texture is based on the size of the individual mineral grains. Grain size depends on the rate in which the magma cooled. The longer it takes to cool, the larger the crystals. Because of this, we can conclude that coarse-grained igneous rocks are "intrusive," in that they cooled below the Earth’s surface where they were insulated by layers of rock and sediment. Fine-grained rocks are then "extrusive" and are usually produced through volcanic eruptions.
o Coarse-grained: the majority of the crystals are >1mmo Fine-grained: the majority of the crystals are <1mm
Materials:Samples of Rocks Hand lens/magnifying glass Container with water Ruler
Procedure:1. Identify the names of the igneous rocks using the flow chart provided. Record all
information on the data table below. 2. Classify the igneous rocks as intrusive or extrusive, mafic, felsic, or intermediate.
Rock #
Coarse-grained, Fine-grained, or no
crystals formed?
Intrusive or Extrusive?
Mafic, Felsic, or Intermediate
Igneous Rock’s Name
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Key Questions
1. Are rocks that have a vesicular texture extrusive or intrusive? _________________
2. Why don’t both intrusive and extrusive rocks have vesicles?
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
3. Which rock(s) cooled the slowest? Explain how you know. _________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
4. Which rock(s) cooled the fastest? Explain how you know. _________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
5. Overall, what 2 things determine what kind of igneous rock forms? Explain your answer. _________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
© 2011 ACQUIRE Lesson Plans
Name: ____________________________________ Date: ________________________ Period: _____Level 3
“Identifying Igneous Rocks” Lab
Background: Igneous rocks are formed when molten rock
cools and hardens. There are two main types of igneous rock: intrusive (magma hardens below earth’s surface) and extrusive (lava hardens on earth’s surface). When magma cools atoms arrange in a repeating pattern to form crystals. Slow cooling magma produces large, crystals. Faster cooling lava produces small crystals. Sometimes lava cools so fast that it hardens (freezes) before any crystals can from. In this case, volcanic glass is created.
Texture is based on the size of the individual mineral grains. Grain size depends on the rate in which the magma cooled. The longer it takes to cool, the larger the crystals. Because of this, we can conclude that coarse-grained igneous rocks are "intrusive," in that they cooled below the Earth’s surface where they were insulated by layers of rock and sediment. Fine-grained rocks are then "extrusive" and are usually produced through volcanic eruptions.
o Coarse-grained: the majority of the crystals are >1mmo Fine-grained: the majority of the crystals are <1mm
Materials:Samples of Rocks Hand lens/magnifying glass Container with water Ruler
Procedure:3. Identify the names of at least 7 igneous rocks using the flow chart provided. Record
all information on the data table below. 4. Classify the igneous rocks as intrusive or extrusive.
Rock # Coarse-grained, Fine-grained, or no crystals formed?
Intrusive or Extrusive? Igneous Rock’s Name
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Key Questions
1. Are rocks that have a vesicular texture extrusive or intrusive? _________________
2. Which rock(s) cooled the slowest? Explain how you know. _________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
3. Which rock(s) cooled the fastest? Explain how you know. _________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
4. What determines what type of igneous rock forms?
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
© 2011 ACQUIRE Lesson Plans
Name: ____________________________________ Date: ________________________ Period: _____Level 1/2
“Identifying Igneous Rocks” LabBackground:
Igneous rocks are formed when molten rock cools and hardens. There are two main types of igneous rock: intrusive (magma hardens below earth’s surface) and extrusive (lava hardens on earth’s surface).
Because Intrusive Igneous rocks form below Earth’s surface, the magma cools very slowly. Slow cooling magma produces large crystals. Most of the crystals are larger than 1 mm.
Extrusive Igneous rocks form on Earth’s surface, so the magma cools very fast. Faster cooling lava produces small crystals. Sometimes lava cools so fast that it hardens (freezes) , so no crystals form . In this case, volcanic glass is created.
Materials:Samples of Rocks Hand lens/magnifying glass Ruler
Procedure:5. For each rock, tell if the crystals are large, small, or if no crystalf formed. 6. Based on crystal size, write if each rock is an Intrusive igneous rock or an Extrusive
igneous rock.
Rock # Large Crystals, Small Crystals, or
No crystals
Intrusive or Extrusive?
© 2011 ACQUIRE Lesson Plans
Key Questions
1. Which rock(s) cooled the slowest?
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
2. Which rock(s) cooled the fastest? _________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
3. Draw or write 2 things you have learned about Igneous Rocks. You may use your notes.
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
_________________________________________________________________________________________________
© 2011 ACQUIRE Lesson Plans
© 2011 ACQUIRE Lesson Plans
Crystals (grain size) is greater than 1mm
IntrusiveIgneous Rocks
Yes
NoExtrusiveIgneous Rocks
Volcanic Glass(Cooled too quickly for
crystals to form)
Not Volcanic Glass(Extremely tiny crystals;
fine grained)
Dark Colored(high in iron and
Magnesium)
Intermediate(about half and half)
Lightly Colored(high in silica and low in
iron and Magnesium)
Vesicular?
Yes
No
Gabbro
Diorite
Floats
Sinks
Dark Colored(high in iron and
Magnesium)
Obsidian
Lightly Colored(high in silica and low in iron and
Magnesium)
Pumice
Scoria
Basalt
Rhyolite
Abnormally large crystals
(3 cm or larger)
Yes
No Granite
Pegmatite