Rock Cycle
Classifying Rocks
Igneous
Metamorphic
Sedimentary
Sedimentary Rock
• Sediment is weathered, eroded,
deposited, compacted, and cemented to
make sedimentary rock.
• Examples:
– Sandstone
– Conglomerate
– Limestone
– shale
Igneous Rock
• Rock material is melted an cooled.
• Magma underground is made of melted
rock.
• If the magma cools slowly underground,
its crystals will be large. Example: granite
• If the magma erupts from a volcano, the
molten rock is called lava. Lava cools
quickly, so crystals will be very small.
Examples: pumice, scoria, obsidian
Metamorphic Rock
• This type of rock was once another type of
rock that was changed due to extreme heat
and pressure, but not melting.
• Magma underground that is near the rock
heats it up, but does not melt it.
• The rock recrystallizes. Examples:
– Limestone becomes marble
– Granite becomes gneiss
– Shale becomes slate
– Sandstone becomes quartzite.
Rock Cycle