Warm-Up 9-12

• If a region of a map has contour lines close together what does that tell you about the region?

• Why do contour lines never overlap?

• Draw a small contour map of a 100m tall mountain with two peaks.

Maps and Topography! To

LITHOSPHERE!

Rocks

What is a Rock?• Naturally-occurring mixtures of

minerals, mineraloids, glass or organic matter.

What is the difference between a rock and a mineral?

• Rocks are made up of ONE or MORE minerals.

Warm-Up. Happy Friday!

• What is magma?• What is lava?• Explain the difference between a rock and a

mineral.• How do rocks form?

Take about 10min to quietly read the article.

Then answer the following questions:

1. What activities in your life are dependent upon the successful work of a geologist?

2. How could an understanding of geology help you understand the world around you?

3. What did you find the most interesting about this article?4. Does anything about this article make you nervous?

What is a Rock?

• Rocks are divided into 3 groups based on how they were formed:

• IGNEOUS•SEDIMENTARY•METAMORPHIC

Igneous Rocks

Igneous rocks are formed from the cooling down of magma or lava.

2 types of igneous rocks

• Intrusive• Extrusive

INTRUSIVE rocks cooled slowly INside of the earth. Composed of larger crystals

EXTRUSIVE means “out of the earth”

It cooled on the surface of the earth and has small crystals

Intrusive

Crystal forming video!

Igneous rocks are classified according to the composition and texture.

Composition is the minerals that the rock is made of

Felsic rocks: light colored, high silica content

Mafic rocks: dark rock, low silica content

Texture is the size, shape, arrangement, and distribution of those minerals in the rock.

There are 4 textures: glassy, fine-grained, course-grained, and porphyritic.

rhyolite

Glassy – obsidian

Fine-grained - basalt

Course-grained - Granite

Porphyritic means that it has large crystals with small ones also.

Sedimentary Rocks

Sediments are pieces of solid material that have been weathered and then deposited

Sedimentary rocks are formed when rocks are broken down into sediments (weathered) and compacted together. (Compaction and cementation)

Sedimentary rocks are classified3 classifications: clastic, chemical, organic

breccia

CLASTIC:1. They are the most common sedimentary rock2. Are made from pieces of previous rock3. Example: “Big Chunks” – Breccia4. Example: Small pebbles, clay, and sand

“glued” together – Conglomerate5. Example: Small sand grains only = sandstone

CHEMICAL ROCKSFormed when a lake or ocean dries up, leaving

behind minerals.

Calcite, Halite, and Gypsum are examples

ORGANIC ROCKSThey are formed from the remains of once living

things

Coal is made from plant remains.

Metamorphic Rocks• Were once igneous or sedimentary rocks• Have been changed because of heat and/or

pressure.• Very strong rock. Resistant to weathering.

GneissSchist

END

• Explain the rock cycle in enough detail to relate the cycling of materials - formation and destruction of the three major rock types to the

• forces responsible: physical and chemical weathering, heat and pressure, deposition, foliation and bedding. The forms of energy that

• drive the rock cycle include heat and mechanical (gravitational potential) energy.

Warm-Up

1. How is an INTRUSIVE igneous rock formed?2. What are the 3 types of sedimentary rocks?3. When are chemical sedimentary rocks

formed?

The Rock Cycle

1. The rock cycle is the continuous changing and remaking of rocks.

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

content/investigations/es0602/es0602page02.cfm

2. Igneous rocks and sedimentary rocks may be transformed by heat, pressure, and chemical reactions into metamorphic rocks.

3. Metamorphic rocks may be changed or metamorphosed into other metamorphic rocks.

They also may be remelted into an igneous rock.

Or a metamorphic rock can be weathered to form a sedimentary rock.

Heat And Pressure

Eroded(broken down)

Melted

Eroded(broken down)

Heat And Pressure

Melted

4. Any rock can be changed into another rock!

Warm Up 2/6

1. Write 3-5 sentences about anything and everything that you know about rocks.

(Things to think/write about: Are there different types of rocks? If so, what makes them different? Why are rocks different colors? Why do rocks have different textures?)

Rock Cycle Vocabulary

Rock

• a mixture of one or more minerals, volcanic glass, organic matter, or other

materials

Sedimentary Rock

• forms when sediments are compacted and cemented together or when minerals

are left behind by evaporation

Examples

Metamorphic Rock

• forms when heat and pressure act on igneous, metamorphic

or sedimentary rock and change its form or make up.

Examples

Igneous Rock

• intrusive or extrusive rock formed when hot magma cools

and hardens

Examples

Rock Cycle

• model that describes how rocks slowly change from one form to another through time

Example

Sediments

• loose materials such as rock fragments, dirt, silt, and sand

Magma

• hot, melted rock material beneath the Earth’s surface

Weathering

• surface process that breaks rocks into smaller pieces

(wind, rain, temperature, etc)

Erosion

• process in which surface materials (sediments) are worn

away and transported from one place to another by water,

wind, and glaciers

Deposition

• The process of eroded materials being moved and deposited in another place.

Cementation

• sedimentary rock-forming process in which large

sediments are held together by natural cements (matrix) like

evaporated mud

Compaction

• process that forms sedimentary rocks when layers

of small sediments are compressed by the weight of

the layers above