Warm-Up

• What are the five characteristics that make a mineral a mineral?

• List 6 ways you can identify a mineral by physical properties?

• How do igneous rocks form? What are the two classifications of igneous rocks?

• How can you differentiate between the two igneous rocks? Give three specific examples

The Rock Cycle Movie

• https://www.youtube.com/watch?v=CvDw07iYaJQ

• Write 5 Facts

• Complete video assessment at the end

What are the differences? Similarities?

Igneous Rock

Metamorphic Rock

Earth’s 5 Structures

inner core

lithosphere

asthenosphere

mantleouter core

This slide show is intended to help you understand important types of rocks.

The diagram in the next slide represents the ROCK CYCLE—a scheme that represents the processes of continuous changes that connect the three major groups of rocks:

SEDIMENTARYIGNEOUSMETAMORPHIC

It also shows two other important parts of the “Rock Cycle” – SEDIMENTS and molten LAVA and MAGMA

Here is another version of the Rock Cycle

Warm-Up

• Define the 3 rock types: igneous, sedimentary, metamorphic

Igneous Rocks Are Separated into Two Main Categories

INTRUSIVE

EXTRUSIVE

Igneous Rocks• Igneous rocks are rocks that are formed from

the crystallization of magma.

Heat and melting

Magma Cooling and crystallization

Igneous Rocks

Sedimentary Rocks

Sedimentary rocks may be made of rock fragments—sediments—or by chemical reactions. The classification of sediments is shown below.

Metamorphic Rocks• Are rocks formed from an increase in pressure

and temperature deep within the lithosphere.

Clastic rocks–made of cemented sediments—are classified by their grain sizes.

Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt.

Biologic sedimentary rocks come from the remains of organic matter.

• The most important of these is coal. Anthracite coal results from the greatest pressure and releases the most energy when burned. Other varieties are bituminous and lignite. “Petrified” (permineralized) wood is another organic rock.

More about sedimentary rocks

• Shale is the most common sedimentary rock

• Sedimentary rocks cover about three-quarters of the land surface

Sedimentary Rocks

• Rocks formed from lithification.

lithification

• transformation of sediments into rock through compaction and cementation

Compaction

the process in which pressure squeezed air and water out and pushes fragments together

pressure comes from rock layers above

Cementation

the process in which water and minerals combine to from cement that holds sediment together.

Three Types of Sedimentary Rocks

• Clastic Sedimentary Rocks• Evaporites Sedimentary Rocks• Organic Sedimentary Rocks

organic - once living

Chemical Sedimentary Rocks

• Formed from minerals that were once dissolved in water

Evaporites

• Formed when a change in temperature caused water to be evaporated

• Examples: Gypsum and Halite

HALITE

GYPSUM

Organic Sedimentary Rock

• formed from the remains of living things

FOSSILIFOROUS LIMESTONE

Metamorphic Rocks• Are rocks formed from an increase in pressure

and temperature deep within the lithosphere.

Metamorphic rocks are classified by how they are

formed.

How are metamorphic rocks classified?

Three Types of Metamorphic Rocks

• Contact Metamorphism – occurs when molten rocks, such as those in an

igneous intrusion, come in contact with solid rock

Regional Metamorphism

• are produced when high temperature and pressure affect large regions of Earth’s crust.

• the grade of regional metamorphism reflects the intensity of temperature and pressure

• classified as low grade, intermediate grade, and high grade.

Metamorphic Rocks Are Classified By Their Texture

MARBLE IS NONFOLIATED

GNIESS IS FOLIATED

Nonfoliated

• composed mainly of minerals that form with blocky crystal shapes.

– Quartzite and marble are two common examples of nonfoliated rocks.

Foliated

• metamorphic rocks are characterized by bands of minerals

• high pressure during metamorphism causes minerals with flat or needlelike crystals to form with their long axes perpendicular to the pressure

Chemical Change• When hot fluids, water or magma, migrate in

and out of the rock during metamorphism the original composition of the rock can change.

• Minerals melt into a liquid state then recombine with other elements to create new minerals.

Mineral Changes• During metamorphism, the minerals in a rock

change into new minerals that are stable under the new temperature and pressure conditions.

Locations, types, and ages of the bedrocks are represented in a geologic map

http://www.state.nj.us/dep/njgs/