1. Soil Rocks and Minerals
4th Grade Science

2. How was the Earth’s Layers formed?
What does the formation of the Earth have to do with rocks?
Crust- the rigid, rocky outer surface of the Earth, composed mostly of basalt and granite. The crust is thinner under the ocean.
Mantle-a rocky layer located under the crust – it is composed of silicon, magnesium, iron, aluminum, and calcium. Convection (heat) currents carry heat from the hot inner mantle to the cooler outer mantle.
Outer core- the molten iron-nickel layer that surrounds the inner core.
Inner core- the solid iron-nickel center of the Earth that is very hot and under great pressure

3. Comparing the layers of Earth to an apple
Apple Peel = Crust Fruit = Mantle Core = Outer Core Seeds = Inner Core

4. Layers of the Earth

5. What are Minerals?

6. Many properties can help identify minerals and rocks.
Minerals can be identified by:
Hardness
Streak
color
Rocks can be identified by:
Texture
Minerals they are made of
How easily they crumble

7. A mineral is a solid object found in nature that has never been alive.

8. Properties of Minerals
Minerals are identified by their properties or characteristics. Some of the properties used to identify minerals are:
Color
Streak
Luster
Hardness
Magnetism

9. Hardness is the measure of how difficult it is for a mineral to be scratched. Mohs Scale

10. What is a rock?
A rock is a naturally formed solid made of one or more minerals.

11. What are the three types of rocks?

12. Rocks can be divided into three broad categories- igneous, metamorphic, and sedimentary.

13. “Layer”
your
brain
with
SEDIMENTARY
ROCKS!

14. sedimentary rock- rock formed from material that
has settled into layers
Wind and water carry small bits of rock. Layers of these bits of rock form and, under pressure, become sedimentary rock. Most sedimentary rocks are formed from layers of sediments that have been compressed under water for long periods of time.

15. “Fire up” your
knowledge of
IGNEOUS
ROCKS!

16. What is a Volcano?

17. Igneous rock- rock that was once melted and then cooled and hardened
Volcanoes bring melted rock (magma) to the surface, where it cools. The cooled rock is igneous.
Igneous rocks or “fire” rocks are formed from hot molten material called magma.

18. “Change” your thoughts about METAMORPHIC ROCKS!

19. metamorphic rock- rock that has been changed by temperature and pressure
Rocks inside the Earth soften from Earth’s high temperature.
Pressure inside Earth then squeezes the rock. The rock
changes into metamorphic rock. Metamorphic means to change form. Metamorphic rocks are formed inside the earth.

20. The Rock Cycle