Rock Cycle Unit
Vocabulary
th
7
Grade Science
Weathering
• The breaking down of Earth’s materials by
natural processes (water, wind, ice, chemicals,
etc.) into smaller pieces or sediments
Erosion
• Weathered rock and soil particles are moved
from place to place by water, wind, or ice
Deposition
• Weathered sediments are laid down in a new
location helping create new landforms or rocks
Melting
• Caused by heat and pressure around the rock
to form magma
Solidification
• Magma or lava cools and hardens
Recrystallization
• Through heat and pressure, the rock’s atoms
and crystals are rearranged
Igneous Rock
• Formed from the cooling and solidification of
magma or lava
• 2 Types
– Extrusive Igneous Rock
– Intrusive Igneous Rock
Extrusive Igneous Rock
• Formed above ground from lava cooling and
hardening
• Characteristics from Cooling Quickly
– Small or no crystals
– Fine-grained texture
Intrusive Igneous Rock
• Formed below ground from magma cooling
and hardening
• Characteristics from Cooling Slowly
– Large or small crystals
– Coarse-grained texture
Sedimentary Rock
• Formed from sediments (rock fragments,
mineral grains, animal or plant remains) that
are pressed or cemented together
• 3 Types
– Clastic Sedimentary Rock
– Organic Sedimentary Rock
– Chemical Sedimentary Rock
Law of Superposition
• States that layers and fossils on top are
younger than lower layers
• Strata – horizontal layers formed from
deposited sedimentary rock
• Stratification – process of arranging
sedimentary rocks into layers
Youngest
Rocks
Here !
Oldest Rocks
Here !
Metamorphic Rock
• Rock changes due to intense heat and high
pressure then recrystallizes
– Not heated enough to melt the rock
• 2 Types
– Foliated Metamorphic Rock
– Non-Foliated Metamorphic Rock
Bands (CAN) Form = Foliated
Metamorphic
means
“changed”
The Rock Cycle