1. Rock Cycle and Rock Types

2. Earth’s 5 Structures lithosphere asthenosphere inner core mantle
outer core

3. This slide show is intended to help you understand important types of rocks.
The diagram in the next slide represents the ROCK CYCLE—a scheme that represents the processes of continuous changes that connect the three major groups of rocks:
SEDIMENTARY
IGNEOUS
METAMORPHIC
It also shows two other important parts of the “Rock Cycle” – SEDIMENTS and molten LAVA and MAGMA

5. Here is another version of the Rock Cycle

7. Igneous Rocks Are Separated into Two Main Categories
EXTRUSIVE
INTRUSIVE

8. Cooling and crystallization
Igneous Rocks
Igneous rocks are rocks that are formed from the crystallization of magma.
Heat and melting
Magma
Cooling and crystallization
Igneous Rocks

9. Sedimentary Rocks
Sedimentary rocks may be made of rock fragments—sediments—or by chemical reactions. The classification of sediments is shown below.

10. Clastic rocks–made of cemented sediments—are classified by their grain sizes.

11. Non-clastic rocks form by chemical precipitation (settling out from a solution.) Limestone is made from calcite, chert from quartz, and halite is rock salt.

12. Biologic sedimentary rocks come from the remains of organic matter.
The most important of these is coal. Anthracite coal results from the greatest pressure and releases the most energy when burned. Other varieties are bituminous and lignite. “Petrified” (permineralized) wood is another organic rock.

13. More about sedimentary rocks
Shale is the most common sedimentary rock
Sedimentary rocks cover about three-quarters of the land surface

14. Making Sedimentary Rocks
Rocks formed from lithification.

15. lithification
transformation of sediments into rock through compaction and cementation

16. Compaction
the process in which pressure squeezed air and water out and pushes fragments together
pressure comes from rock layers above

17. Cementation
the process in which water and minerals combine to form cement that holds sediment together.

18. Three Types of Sedimentary Rocks
Clastic Sedimentary Rocks
Evaporites Sedimentary Rocks
Organic Sedimentary Rocks
organic - once living

19. Chemical Sedimentary Rocks
Formed from minerals that were once dissolved in water

20. Evaporites
Formed when a change in temperature caused water to be evaporated
Examples: Gypsum and Halite
GYPSUM
HALITE

21. Organic Sedimentary Rock
formed from the remains of living things
Sedimentary rocks are the only rocks with fossils
FOSSILIFOROUS LIMESTONE

22. Metamorphic Rocks
Are rocks formed from an increase in pressure and temperature deep within the lithosphere.

23. Metamorphic rocks are classified by how they are formed.
How are metamorphic rocks classified?
Metamorphic rocks are classified by how they are formed.

24. Three Types of Metamorphic Rocks
Contact Metamorphism
occurs when molten rocks, such as those in an igneous intrusion, come in contact with solid rock

25. Regional Metamorphism
are produced when high temperature and pressure affect large regions of Earth’s crust.
the grade of regional metamorphism reflects the intensity of temperature and pressure
classified as low grade, intermediate grade, and high grade.

26. Metamorphic Rocks Are Classified By Their Texture
GNIESS IS FOLIATED
MARBLE IS NONFOLIATED

27. Nonfoliated
composed mainly of minerals that form with blocky crystal shapes.
Quartzite and marble are two common examples of nonfoliated rocks.

28. Foliated metamorphic rocks are characterized by bands of minerals
high pressure during metamorphism causes minerals with flat or needlelike crystals to form with their long axes perpendicular to the pressure

29. Chemical Change
When hot fluids, water or magma, migrate in and out of the rock during metamorphism the original composition of the rock can change.
Minerals melt into a liquid state then recombine with other elements to create new minerals.

30. Mineral Changes
During metamorphism, the minerals in a rock change into new minerals that are stable under the new temperature and pressure conditions.

31. Locations, types, and ages of the bedrocks are represented in a geologic map