Introduction to Rocks

Introduction to Rocks 7th grade science

Rocks are a combination of minerals What are rocks?

No Not only are they different colors, but there are also different types The three main types are igneous, sedimentary, and metamorphic rocks. Are all rocks the same? Igneous: Granite Metamorphic: Gneiss Sedimentary: Sandstone

Rocks are created, transformed, and destroyed in a process called the rock cycle Interactive Rock Cycle Animation Where do rocks come from? http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html

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. The rock cycle: Part 1

Can be: Shiny Crystalline Porous Igneous Rocks http://geology.about.com/library/bl/images/blrockindex.htm

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. The rock cycle: Part 2

Can be: Grainy, Sandy Made of different pieces of rocks or minerals Striped Sedimentary Rocks

Finally, rocks can be transformed over time to make new rocks. Heat and pressure can create new rocks These rocks are called Metamorphic rocks. The rock cycle: Part 3 http://www.tulane.edu/~sanelson/geol111/metamorphic.htm

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 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. • True • False

Correct! Click to Continue…

Sorry, Try again. Click to Continue…

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

3. Igneous rocks… • Can be formed from pieces of sediment that have been compacted and glued together. • Can be formed from molten magma or lava. • Are formed when heat and pressure transform old rocks into new rocks.

4. Sedimentary rocks… • Can be formed from pieces of sediment that have been compacted and glued together. • Can be formed from molten magma or lava. • Are formed when heat and pressure transform old rocks into new rocks.

5. Metamorphic Rocks • Can be formed from pieces of sediment that have been compacted and glued together. • Can be formed from molten magma or lava. • Are formed when heat and pressure transform old rocks into new rocks.

The End

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

Introduction to Rocks