Rocks!

Goal 2.1

Lesson 2

Igneous Rocks

Think About It…

What is the ultimate source of

all solid, non-living material

on Earth?

Focus Question…

How are igneous rocks

formed, classified, and used?

About Igneous Rocks…

• Meaning of the

word igneous…

– Igneous is

Latin for fire!

Volcano in the Philippines

http://news.bbc.co.uk/2/hi/in_pictures/5198238.stm

How Igneous Rocks Form …

• How do igneous rocks form? 1. Igneous rocks are

formed from the crystallization of magma.

2. Three factors that affect magma formation are

1. temperature

2. pressure

3. water content

http://news.bbc.co.uk/2/hi/in_pictures/5198238.stm

Practical Uses of Igneous

Rocks… Practical Uses of Igneous Rocks…

1. As construction materials – granite

2. As valuable ore deposits – silver, gold, lead, copper

3. Pegmatites contain gemstones

4. Kimberlites contain diamonds. See next slide.

http://www.granite-counter-tops.org/granite-sink-424.jpg

Granite countertop

http://gccweb.gccaz.edu/earthsci/imagearchive/PEGMATITE_tn.jpg

Pegmatite

A Giant Amethyst – Washington

DC

Kimberlites • In South Africa in the

1860’s, it was

discovered that

kimberlites were the

source of diamonds.

http://www.diamond-all.com/Diamond.html

Classification of Igneous

Rocks E

X

T

R

U

S

I

V

E

Felsic Intermediate Mafic Texture

I

N

T

R

U

S

I

V

E

-------

----------

--------

For pictures, see next slide…

obsidian and pumice

Basaltic glass

glassy

rhyolite andesite basalt fine

gabbro coarse granite

pegmatite

Very coarse

Extrusive

Rocks… o Pumice (glassy)

o Obsidian (glassy)

o Basalt (fine grained)

o Small to no crystals!

(glass)

http://geology.com/rocks/pumice.shtml

Hawaii’s Black Sand Beach – Eroded Basalt…

Intrusive

Rocks…

• Granite (coarse)

• Gabbro (coarse)

• Diorite (coarse)

• Large to very large

crystals!

diorite

granite

gabbro

Mount Rushmore – Granite

Faces!

Hawaii’s Green Sand

Beach…Eroded Olivine

www.lovingthebigisland.wordpress.com

www.skywalker.cochise.edu

Compare Extrusive to

Intrusive… • Both are mafic.

• Basalt cooled above

ground.

• Gabbro cooled

underground.

gabbro

basalt

Compare Extrusive

to Intrusive… • Both are felsic.

• Obsidian cooled

above ground.

• Granite cooled

underground.

granite

obsidian

Lesson 3

Sedimentary Rocks

Think About It…

What would happen to an

animal if it fell into lava?

Focus Question…

How are sedimentary rocks

formed, classified, and used?

About Sedimentary Rocks…

• The word

“sediments”

means…

– Pieces of solid

material

deposited on

Earth’s surface

http://science.nasa.gov/science-news/science-at-nasa/2001/ast23jan_1/

Types of Sediment

(smallest to biggest) • Clay

• Silt

• Sand

• Pebbles or gravel

http://techalive.mtu.edu/meec/module06/SoilClassification.htm

Types of Sediment

(smallest to biggest)

http://school.discoveryeducation.com/schooladventures/soil/name_soil.html

How Sedimentary Rocks

Form…

1.Rocks are weathered meaning…

–Big pieces are broken down into smaller pieces. Arches National Park in Utah –

weathered rocks become arches!

http://www.nationaloutdoors.net/files/images/arches_national_park.gif

How Sedimentary Rocks

Form…

2.Sediments are

eroded

meaning…

They are

removed to

another

location.

http://drake.marin.k12.ca.us/stuwork/rockwaterl

How Sedimentary Rocks

Form…

3.Sediments are

deposited

meaning…

– They are put

down

somewhere

else. Deposition of sediments

along a stream http://ag.arizona.edu/extension/riparian/chapt4/p5.html

How Sedimentary Rocks

Form…

4. Sediments are

buried.

How Sedimentary Rocks

Form…

5. Sediments are

lithified or turned

into stone by the

processes of…

a. compaction

b. cementation

http://faculty.ksu.edu.sa/alhomadhi/Sandstone/Forms/DispForm.aspx?ID=14

Sedimentary Rocks in the

Badlands (South Dakota)

Sedimentary Rock (Layers and

Erosion) – Badlands, S. Dakota

Importance of Sedimentary Rocks…

1. Sedimentary rocks

often contain

fossils which can

give us clues to the

past.

A trilobite preserved in sedimentary rock. http://www.fossilsforkids.com/

Aunt Pearl’s Fossil Farm East Tennessee

http://www.grayfossilmuseum.com/

http://www.grayfossilmuseum.com/?CONTEXT=art&cat=25&art=85&BISKIT=1941568670

Aunt Pearl’s Fossils (Short-face Bear)

http://boneblogger.com/how-big-was-the-giant-short-faced-bear/

Aunt Pearl’s Fossils (Saber Tooth Cat)

http://igs.indiana.edu/FossilsAndTime/Sabertooth.cfm

Aunt Pearl’s Fossils (Red Panda)

http://en.wikipedia.org/wiki/File:RedPandaFullBody.JPG

Aunt Pearl’s Fossils (Tapir) http://www.zooborns.com/zooborns/2013/01l

http://tapirs.org/tapirs/

Importance of Sedimentary Rocks…

2. Energy sources

(fossil fuels) such

as

1.oil

2.natural gas

3.coal

Sedimentary rock layers with petroleum and

natural gas deposits.

http://teeic.anl.gov/images/photos/third_stage_OG_formation.gif

Open-pit Coal Mine (Wyoming)

Coal-burning Power Plant –

Jacksonville, FL

Importance of Sedimentary Rocks…

3. Uranium, a

nuclear fuel, is

found in the

sedimentary

rock known as

sand stone.

Uranium containing sandstone found in

Colorado

http://www1.newark.ohio-state.edu/Professional/OSU/Faculty/jstjohn/Minerals/Carnotite.htm

Importance of Sedimentary Rocks…

4. Limestone is

processed to

make cement

for the

construction

industry.

Miami limestone!

http://www.dep.state.fl.us/geology/geologictopics/rocks/miami_limestone.jpg

Corvette Museum Sinkhole…

http://www.usatoday.com/story/money/cars/2014/02/21/corvette-museum-sinkhole/5674659/

Classification of Sedimentary Rocks… Clastic (broken)

1. Coarse-grained- conglomerate (gravel/pebbles)

2. Medium-grained – sandstone (sand)

3. Fine-grained – shale (clay)

4. These form when broken pieces of sediment are cemented together.

conglomerate sandstone shale

Classification of Sedimentary Rocks…

Chemical

1. Calcite - limestone

2. Halite – rock salt

3. Gypsum – rock gypsum

4. These form when water evaporates leaving the rock behind.

limestone halite

Classification of Sedimentary Rocks… Organic (from living things)

1. Shells – coquina limestone (shells & calcium carbonate)

2. Plant matter (swampy) – coal

3. These form from living things that get turned into

rock!

coquina limestone coal

http://www.dep.state.fl.us/geology/geologictopics/rocks/miami_limestone.jpg

Coquina Rocks in North Florida…

Coquina in

North Florida

www.uky.edu

Most of the coal burned in the USA is bituminous.

Lesson 4

Metamorphic Rocks

Think About It…

What happens to a caterpillar

during metamorphosis?

Focus Question…

How are metamorphic rocks

formed, classified, and used?

About Metamorphic Rocks…

• Metamorphic is

Greek for…

– change in

form

http://www.yourdictionary.com/images/main.metamorphosis.jpg

How Metamorphic Rocks

Form…

A metamorphic rock forms when high temperatures

and pressure combine to alter the texture,

mineralogy, or chemical composition of a rock

WITHOUT MELTING IT!

• Link to view a visualization of the process…

• http://www.classzone.com/books/earth_science/terc

/content/visualizations/es0607/es0607page01.cfm?

chapter_no=visualization

How Metamorphic Rocks

Form…

• Three types of

metamorphism may

change rocks…

a. Regional

b. Contact

c. Hydrothermal

http://www.fi.edu/fellows/fellow1/oct98/create/metamorph.htm

Practical Uses of

Metamorphic Rocks…

1. Contain economically

valuable minerals –

talc and garnets

2. Marble is used in

sculpting.

3. Deposits of gold, and

lead are formed by

metamorphism.

http://facstaff.gpc.edu/~pgore/geology/geo101/meta.htm

http://gurneyjourney.blogspot.com/2009/01/arc-of-hollows.html

Monument in Marble (GA white and TN)…

David…

http://www.firenzeturismo.it/aptgest/images/stories//musei//0056-al_accademia_david_di_michelangelo.jpg

Classification of Metamorphic Rocks…

• Foliated…

– Have wavy layers or bands that are caused by minerals with flat crystals that form long axes perpendicular to the pressure

1. Slate from shale

1. Schist from shale (buried

deeper)

2. Gneiss from granite

Mount Rushmore – Also contains mica

schist

Classification of Metamorphic Rocks…

• Nonfoliated…

– Lack mineral grains with long axes in one

direction. They form minerals that have

blocky crystal shapes.

2. Marble from limestone

1. Quartzite from sandstone

3. Hornfels from basalt

Bituminous Coal Morphs into Anthracitic

Coal…

Lesson 5

The Rock Cycle

Think About It…

How could you turn any rock

into an igneous rock?

Focus Question…

What are the processes that

turn one rock into another?

The Rock Cycle…

• How are igneous rocks formed?

– By melting, cooling, and crystallization

• What happens to igneous rocks that undergo

weathering and erosion?

– They become sediments

• How do sediments become sedimentary rocks?

– By deposition, burial, and lithification

(compaction and cementation)

The Rock Cycle (continued)…

• What forces cause sedimentary rocks to be

transformed into metamorphic rocks?

– Heat and pressure – without melting!

• How can metamorphic rock be transformed into

igneous rock?

– By melting, cooling and crystallization of

magma

• How can sandstone be transformed into

sediment?

– By weathering and erosion

The Rock Cycle…

http://www.personal.psu.edu/cll161/insys%20441/images/rock_cycle.jpg

The Rock Cycle – An

Animation…

http://www.learner.org/interactives/rockcycle/diagram.html

http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html

The Mystery of the Sliding Rocks…

• http://geology.com/nasa/racetrack-playa/