Introduction to Rocks

7th grade science

What are rocks? Rocks are a combination

of minerals

Are all rocks the same? No Not only are they different

colors, but there are also different types

The three main types are igneous, sedimentary, and metamorphic rocks.

Igneous: Granite

Sedimentary: Sandstone

Metamorphic: Gneiss

Where do rocks come from? Rocks are created,

transformed, and destroyed in a process called the rock cycle

Interactive Rock Cycle Animation

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

The rock cycle: Part 1 First of all there is no real

beginning or end to the rock cycle.

However, for this lesson we will begin with igneous rocks.

Igneous rocks often forms when lava erupts from volcanoes then cools.

Igneous Rocks

Can be: Shiny Crystalline Porous

http://geology.about.com/library/bl/images/blrockindex.htm

The rock cycle: Part 2 Secondly, the rock cycle is

not a perfect circle, it does not occur in a specific sequence.

Igneous rocks can be re-melted, eroded, or pressed.

Rocks that are formed from eroded sediment are Sedimentary Rocks.

Sedimentary Rocks

Can be: Grainy, Sandy Made of different pieces

of rocks or minerals Striped

The rock cycle: Part 3 Finally, rocks can be

transformed over time to make new rocks.

Heat and pressure can create new rocks

These rocks are called Metamorphic rocks.

http://www.tulane.edu/~sanelson/geol111/metamorphic.htm

Metamorphic Rocks

Come in a variety of styles, shapes and colors

Many have stripes, but not all

Many contain unique crystal and mineral formations only unique to metamorphic rocks

Review

There are review questions about rocks on the following slides.

In order to progress through the quiz in the correct order you have to click the links on the slides.

Click the “Begin Quiz” link on this page to start the quiz.

Begin Quiz

1. True or False: The rock cycle always starts with igneous rocks and

ends with metamorphic rocks.

A. True

B. False

2. True or False: The rock cycle does not always follow the same order.

A. True

B. False

3. Igneous rocks…

A. Can be formed from pieces of sediment that have been compacted and glued together.

B. Can be formed from molten magma or lava.

C. Are formed when heat and pressure transform old rocks into new rocks.

4. Sedimentary rocks…

A. Can be formed from pieces of sediment that have been compacted and glued together.

B. Can be formed from molten magma or lava.

C. Are formed when heat and pressure transform old rocks into new rocks.

5. Metamorphic Rocks

A. Can be formed from pieces of sediment that have been compacted and glued together.

B. Can be formed from molten magma or lava.

C. Are formed when heat and pressure transform old rocks into new rocks.

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

http://geology.about.com/library/bl/images/blrockindex.htm http://www.tulane.edu/~sanelson/geol111/metamorphic.htm