Download Virtual Rock Hounding

Name: _________________________________
Date: _________________
Period: ______
2.2 Classifying Rocks
Chapter 2: Minerals & Rocks (S, P)
Essential Questions:
What should I know by the end of this lesson…?
1. How do geologists classify rocks?
Previewing Vocabulary:
Word & Definition:
ROCK-FORMING MINERAL –
Use it in a sentence:
What does it look like?
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GRANITE –
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BASALT –
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GRAIN –
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Fry 2015
Name: _________________________________
Word & Definition:
TEXTURE –
Date: _________________
Use it in a sentence:
Period: ______
What does it look like?
_________________________________________________
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IGNEOUS ROCK –
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SEDIMENTARY ROCK –
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METAMORPHIC ROCK –
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
Exploring Chapter 2: Lesson 2
(pages 44-47)
What is the essential question for this chapter? Write it below.
1. _____________________________________________________________________________
How did you find the essential questions?
___________________________________________________________________________________
What is the only MAIN HEADING (blue/green) for this lesson? Write it below.
___________________________________________________________________________________
What are the three SUBHEADINGS (red) for the main heading?
1. _____________________________________________________________________________
What are three facts from the paragraphs under the first subheading?
Please write them in complete sentences below.
a) _____________________________________________________________________
_____________________________________________________________________
b) _____________________________________________________________________
_____________________________________________________________________
c) _____________________________________________________________________
_____________________________________________________________________
2. _____________________________________________________________________________
What does the word grain mean?
a. A crop that grows in a field.
c. The way a rock was formed.
b. Little particles of minerals or rocks.
d. None of the above.
Draw a picture of rocks to match each of the descriptions below:
FINE GRAIN
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COARSE GRAIN
ROUNDED GRAIN
JAGGED GRAIN
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NON-BANDED GRAIN
BANDED GRAIN
Fry 2015
Name: _________________________________
Date: _________________
Period: ______
3. _____________________________________________________________________________
What does the word origin mean?
e. What planet the rock came from.
g. The way the rock was formed.
f.
h. None of the above.
What country the rock came from.
Draw a picture of your best interpretation of rock formation. Draw an
example of each of the three rock types forming below.
IGNEOUS ROCK FORMATION:
SEDIMENTARY ROCK FORMATION:
METAMORPHIC ROCK FORMATION:
Write the answer to the essential question below:
1. To study a rock sample, geologists ________________________ the rock’s _______________
____________________, color, and __________________. Geologists have ________________
rocks into ___________ major groups: _______________ rock, ___________________ rock,
and ______________________rock.
2.2 Classifying Rocks
How Do Geologists Classify Rocks?
1a. REVIEW Geologists classify rocks according to their
b. EXPLAIN How do igneous rocks form?
c. CLASSIFY Pumice is a type of rock that forms from molten material that erupts violently from a volcano. To what
group of rock does pumice belong?
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
How do geologists classify rocks?
To organize, or sort, items according to similarities in their characteristics is to:
__________________________________________
List some characteristics that you might
use to sort your MONSTERS below:
If you were a geologist, what characteristics
might you use to classify ROCKS?
To study a rock sample, geologists observe…
1. ____________________ 2. ____________________ 3. ____________________
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Name: _________________________________
Date: _________________
Period: ______
1. MINERAL COMPOTISION
What are “ROCK-FORMING MINERALS”?
_____________________________________________________________________
_____________________________________________________________________
How many rock-forming minerals are in Earth’s crust?
_______
2. COLOR
What mineral characteristic is one of the most
helpful in determining a rock’s identity?
What color is GRANITE?
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How is GRANITE different from BASALT?
(describe TWO characteristics)
WHY?
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Does color alone provide enough information to identify a rock?
YES
NO
3. TEXTURE
What is TEXTURE?
_____________________________________________________________________
_____________________________________________________________________
Explain the importance of GRAINS.
What is responsible for giving a rock its TEXTURE?
_________________________________________
_________________________
_________________________
_________________________
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Name: _________________________________
Date: _________________
Period: ______
The MINERAL COMPOSITION, COLOR, and TEXTURE of rocks
helps us to determine the rock’s:
_______________________
What does this mean?
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
Geologists have classified rocks into THREE major groups...
1.__________
2.__________
3.__________
How are these rocks formed?
How are these rocks formed?
How are these rocks formed?
________________________________
________________________________
________________________________
________________________________
________________________________
________________________________
________________________________
________________________________
________________________________
Draw a picture below to help you remember how each type forms…
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Fry 2015
Name: _________________________________
Date: _________________
2.2 Classifying Rocks
Period: ______
Understanding Main Ideas
Answer the following questions using your text book.
1.
What characteristics do geologists observe when studying a rock sample?
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
2. Name the three major groups of rocks and describe how each forms.
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
_______________________________________________________________________________________________________
Please use page 46 in your book to fill in the missing information in the table below.
Grain Property
Description
Texture
Size
Large, easy to see
3.
Size
4.
Fine-grained
Shape
Mineral crystals
Crystalline
5.
Rock fragments
Rounded or jagged
6.
Layered or random grains
Banded or nonbanded
Building Vocabulary
Fill in the blank to complete each statement. Please use your 2.2 vocabulary sheet.
7.
___________________________ is a dark-colored rock with a relatively low
silica content.
The look and feel of a rock’s surface is its __________________________.
9.
The particles of minerals or other rocks that make up a rock are called
.
___________________________.
.
12. ___________________________
rock forms when rock particles get pressed
and cemented together.
13. ___________________________ rock forms when a rock is changed by heat
10. The 20 minerals make up most of the rocks of Earth’s crust are known as
or pressure.
14. ___________________________ rock forms when magma or lava cools and
.
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___________________________ is generally a light-colored rock with a high
silica content.
8.
___________________________.
11.
hardens.
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
How do geologists classify rocks?
Virtual Rock Hounding
There are hundreds of different kinds of rocks, but all are classified as
either igneous, sedimentary, or metamorphic. In this Planet Diary
activity, you'll do some virtual rock hounding to identify and sort rocks.
www.planetdiary.com/_is/0222
Directions
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Compare igneous, sedimentary, and metamorphic rocks. For this activity, you'll identify eight rocks. Click the links
(or look on the next few pages) for each kind of rock to learn more about it.
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Which of the eight rocks matches each description in the Workspace table? What type is it? Use the information to
complete the table.
Workspace
DESCRIPTION:
ROCK NAME:
ROCK TYPE:
Porous, light rock that forms from explosive volcanic eruptions.
Coarse-grained rock that forms from sandstone.
Hard, black volcanic rock with low silica content.
Made up of sand particles cemented together.
Forms from limestone.
Forms when a body of seawater becomes closed off and
evaporates.
Made up of silt particles cemented together.
Dense, shiny volcanic glass.
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
IGNEOUS Rocks:
Andesite is a gray to black volcanic rock. It is generally erupted from stratovolcanoes as thick lava
flows. It can also generate strong explosive eruptions to form pyroclastic flows.
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Andesites erupt at temperatures between 900 and 1100° C.
Andesite contains crystals composed of plagioclase feldspar, pyroxenes, and hornblende.
The word andesite comes from the Andes Mountain Range where andesite is common.
Basalt Lava - Basalt is a hard, black volcanic rock. Less than ½ of the weight of basalt is silica (SiO2).
Because of basalt's low silica content, it has a low viscosity (resistance to flow). This enables basaltic
lava to flow quickly and allows volcanic gases to escape without explosive events.
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The minerals in basalt include olivine, pyroxene, and plagioclase.
Basalt is erupted at temperatures between 1100 to 1250° C.
Basalt is the most common rock type in the Earth's crust most of the ocean floor is made of
basalt.
Basaltic magma is commonly produced by direct melting of the Earth's mantle
Dacite lava is most often light gray, but can be dark gray to black. It is one of the most common rock
types associated with enormous Plinian-style eruptions.
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Dacite lava consists of about 63 to 68 percent silica (SiO2).
Dacite generally erupts at temperatures between 800 and 1000°C
Dacite has a high crystal content. This combined with a high silica content makes it viscous
and prone to explosive eruptions.
Dacite was erupted from Mount St. Helens 1980-86
Pumice is light and porous. It forms during explosive eruptions. Pumice is full of holes caused by
expanding volcanic gases. It is composed of volcanic glass and minerals, and can form in all types of
magma: basalt, andesite, dacite, and rhyolite.
Obsidian is usually black in color though it can also be red or have a greenish tint. It is a dense
volcanic glass, usually composed of rhyolite, rich in iron and magnesium. Obsidian is formed when the
lava cools so quickly that crystals do not have time to grow. Obsidian fractures with very sharp
edges. It was used by Stone Age cultures for making knives, arrowheads, and other tools where
sharp edges are important.
Rhyolite is a light-colored volcanic rock. It has a high silica content which makes it very viscous. This
prevents gases from escaping causing rhyolite eruptions to be explosive.
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Rhyolite has a silica (SiO2) content greater than about 68 percent by weight.
Common mineral types include quartz, feldspar and biotite
Rhyolite is erupted at temperatures of 700 to 850° C.
Rhyolite eruptions often produce pumice or obsidian
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
CLASTIC SEDIMENTARY Rocks:
Conglomerate is made up of rounded pebbles cemented together. The pebbles have been rounded by the
action of moving water. This could be from a river or stream or from waves on a long ago beach. Because
they have been transported by water the pebbles may be from a wide variety of rock types. The size of these
rock fragments is over 2 mm in diameter.They are often sorted by size.
After the pebbles have been deposited they are compacted by the sediments that pile up on top of them. Over
very long periods of time the pebbles become cemented together by minerals. Silica, calcite, and iron oxides
are the most common cementing minerals.
Breccia is very similar to conglomerate. The main thing that is different is that the pebbles in breccia have
not been rounded by the action of moving water as in a conglomerate. Breccia is made up of angular
pebbles cemented together. The size of these rock fragments is over 2 mm in diameter. After the pebbles
have been deposited they are compacted by the sediments that pile up on top of them. Over very long periods
of time the pebbles become cemented together by minerals.
Silica, calcite, and iron oxides are the most common cementing minerals. The angular pebbles in the breccia
are easily visible to the naked eye.
Sandstone is made up mostly of quartz. There are two reasons for this. First quartz is one of the most
abundant minerals on earth. Second is that quartz is very durable. It resists weathering and chemical
change.
Silica, calcite, and iron oxides are the most common cementing minerals for sand stone. These minerals are
deposited in the spaces between the sand grains by water.
Over the course of thousands or even millions of years the minerals fill up all of the spaces.
Siltstone is made from silt particles cemented together. Once deposited the silt becomes compacted and
cemented together into solid stone.
Silica, calcite, and iron oxides are the most common cementing minerals for siltstone. These minerals are
deposited in the spaces between the silt grains by water. Over the course of thousands or even millions of
years the minerals fill up all of the spaces resulting in solid rock.
Shale is made from silt particles cemented together. It is similar to siltstone but with even finer grain size. It
is a very common sedimentary rock.
It is composed of silt or clay. This is very fine particles of weathered and deconposed rock.
Once deposited the silt becomes compacted and cemented together into solid stone.
Silica, calcite, and iron oxides are the most common cementing minerals for shale. These minerals are
deposited in the spaces between the silt grains by water.
Over the course of thousands or even millions of years the minerals fill up all of the spaces. Shale is usually
found in layers.
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
CHEMICAL SEDIMENTARY Rocks:
Halite is also known as rock salt. The chemical name is sodium chloride NaCl It is called an evaporate. It
forms in places where sea water has been isolated from the ocean forming a lake. As the saltwater
evaporates in the lake the salt becomes concentrated in the remaining water. As the water continues to
evaporate the lake can no longer hold the same amount of salt. The salt precipitates out and is deposited as
crystallized sodium chloride or salt.
Selenite is a very common chemical sedimentary mineral. There are three kinds of chemical sedimentary
rocks: Evaporates, Carbonates, and Siliceous rocks. Selenite is one of the evaporates.
Salt is a well known evaporate. Most table salt comes from Utah. The Great Salt Lake is what is left of a huge
inland sea that once covered most of the western United States. It is slowly shrinking in size due to
evaporation. As the water evaporates the lake can no longer hold the same amount of salt. The salt
precipitates out and is deposited as crystallized halite. The salt found in your kitchen is an example of this
evaporate rock.
Limestone is made primarily of calcium carbonate or calcite. The most common source of this calcite is the
shells of marine organisms.
Fossiliferous Limestone is limestone that contains the remains of ancient plants or animals in the form of
fossils.
ORGANIC SEDIMENTARY Rocks:
Coal is composed of organic matter in the form of plant fragments. Coal can be:
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Lignite is black and has a crumbly consistency.
Bituminous coal can be dull to shiny and black.
Anthacite is usually considered metamorphic
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Fry 2015
Name: _________________________________
Date: _________________
Period: ______
METAMORPHIC Rocks:
Quartzite is a coarse-grained metamorphic rock derived from sandstone.
Marble is a metamorphic rock that comes from metamorphosed limestone or dolomite.
Slate is a fined grained metamorphic rock.
Phyllite is a fined grained metamorphic rock.
Schist is a coarse grained metamorphic rock.
Gneiss is a medium to coarse grained metamorphic rock.
All pictures on this page are courtesy of the USGS - United States
Geological Survey. Discriptions are adapted from the USGS.
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Fry 2015