1. The Rock Cycle

2. The Rock Cycle
…is the natural process that rocks in the Earth's crust go through, that involves them continuously transforming into igneous, sedimentary, and metamorphic rocks.

3. What is a Rock? Naturally Occurring (not man made) Solid
Mixture of minerals and organic matter

4. What makes a rock different from a mineral?
Both
Mineral
Made of one or more minerals
Solid
Made of 1 type of element
Random crystal or no crystal structure
Naturally Occurring
Orderly crystal structure
Quartz
Granite = Feldspar
Muscovite

5. Types of Rocks Sedimentary: Sandstone Metamorphic: Gneiss Igneous:
Diorite

6. Igneous
Rocks

7. Igneous Rocks are formed from Magma and Lava
Igneous rocks are classified by where they form
Intrusive
Extrusive
vs.
forms when magma
cools in the Earth
forms when lava cools
on Earth’s surface

8. Intrusive Vs. Extrusive
Diorite Granite Basalt Andesite
Ask the students to take a few minutes to compare intrusive to extrusive. You could have them brainstorm on whiteboards as a group or a piece of paper and then share their observations.
Pegmatite Gabbro Rhyolite Scoria 8

9. Extrusive (earth surface)
Igneous Rocks:
Crystal Size and Cooling Time
Location of Rock
Intrusive (in earth)
Extrusive (earth surface)
Crystal Size
Large crystals
Small crystals
Picture
Cooling time
Longer cooling time
Shorter cooling time 9

10. Sedimentary
Rocks

11. Sedimentary Rocks form from sediment or rock particles
Sediment = material that is deposited by air, water, or ice.
These materials can be:
tiny pieces of rock
broken minerals
pieces of plants and animal remains

12. How do sedimentary rocks form?
Sediments pile on top of each other on land or in water.
As sediments pile, they become compacted and cemented together.
This forms cemented layers of sediment.

13. Sedimentation Process

14. Sedimentary Rock Layers

15. Sedimentary Rock Layers

16. Some rocks form from plants or shells
Coal- created from the remains of plants
(dead wood, bark, leaves, stems, and roots)
The coal we use today
started forming millions
of years ago in swamps
Limestone- created from the shells and skeletons of ocean organisms.

17. Limestone Formation

18. Metamorphic
Rocks

19. Metamorphic Rocks Extreme heat and pressure can change rocks.
The original rock is called the parent rock
The new rock formed is called the metamorphic rock
Heat and pressure change the structure of the parent rock and their minerals recrystallize

20. Examples of Metamorphic Rocks
Extreme heat
and pressure
Parent Rock
Shale
Metamorphic Rock
Slate

21. Examples of Metamorphic Rocks
Extreme heat
and pressure
Parent Rock
Limestone
Metamorphic Rock
Marble

22. Examples of Metamorphic Rocks
Extreme heat
and pressure
Parent Rock
Mica
Metamorphic Rock
Phyllite

23. A little bit more about igneous rocks…
Granite
Rhyolite

24. IGNEOUS ROCKS
GABBRO
BASALT

25. Composition of Igneous Rocks
Igneous rocks are mainly composed of silicate minerals (quartz, feldspar,etc.)
Rocks with high silicate levels-are typically light in color
ex: granite, rhyolite
Rocks with low silicate levels- dark in color
ex: gabbro and basalt

26. Igneous rocks make long-lasting landforms
Intrusive rock formations-as magma pushes up toward Earth’s surface, it makes channels and other formations underground.
Extrusive rock formations-
builds plateaus when erupting from long crack
gently sloping volcanoes (Hawaiian
islands)
cone-shaped volcanoes
(1). contains greater amount of silica
(2). erupts explosively
(3). Mount St. Helens is an example

27. RECAP:
Rock cycle-the set of natural processes that form, change, break down, and re-form rocks

28. Rocks are always changing by processes like:
When a rock forms, does it stay that way forever?
NO!!!!!!
Rocks are always changing by processes like:
Weathering
Melting
Erosion
Cooling
Compaction
Cementation

29. Our world is built of rocks
Rocks have many purposes
used to build houses and skyscrapers
great source of metals
used to carve statues and other works of art

31. 11. Rock Cycle Rocks can change from one category or rock into another
The rocks can move through the cycle in many ways, there is no particular order they must follow 31

32. Rock Cycle animation
Click the link in the title to go to an animation of the rock cycle.