The document discusses the rock cycle, which describes how rocks constantly change form through various natural processes. Rocks can be broken down by weathering into sediments and then transported by erosion. These sediments may be deposited, compacted, and cemented to form sedimentary rocks. Increased heat and pressure can metamorphose sedimentary and igneous rocks. Melting of rocks forms magma that cools and solidifies into new igneous rocks. This cyclic process results in rocks continuously changing their shape and composition over geological time.

1. Rock Cycle
Notes

2. Rock Definition
• Solid mixture of crystals of one or more
minerals

3. Value of Rock
• Natural resource
– Used as tools and weapons (hammers, spears,
knives)
– Used in buildings, roads, and monuments

4. Value of Rock ‐ History
• Important to scientists
– Help answer questions about the history of earth
and the solar system.
• Record of what the Earth used to be
• Fossils

5. Rock Cycle
• Rocks are constantly changing
• Changes shape and composition

6. Rock Cycle Processes
• Erosion
• Deposition
• Compaction and Cementation
• Metamorphism
• Melting
• Cooling
• Solidification
• Weathering

7. Rock Cycle Processes
• Weathering
– Rocks attacked by weather
• Air, moisture, and living
things
– Rocks broken down into
sediments
• Erosion
– Sediment is transported by
wind, water, ice or gravity

8. Rock Cycle Processes
• Deposition
– Sediments settle to the bottom
• Compaction and Cementation
– Compaction
• Layers form on top of each other
• Air and water pushed out
– Cementation
• Loose sediments are glued
together by natural glue

9. Rock Cycle Processes
• Metamorphism
– Means changed form
– Increased heat and
pressure
– Changes a rock into a
metamorphic rock

10. Rock Cycle Processes
• Melting
– Rocks deep in Earth melt and become magma
• Cooling
– Magma cools
• Solidification
– Rock solidifies

14. Rock Classification
• How they are formed
• Where they are formed
• Composition
– Minerals that make up a rock
• Texture
– Sizes, shapes, and positions of the grains