Download Rocks and Minerals

Rocks
Notes
Processes that form rocks:
• Melting:
• Heating in the Earth causes rocks to melt forming
magma (melted rock beneath the Earth’s surface).
• Cooling & Hardening:
• Magma rises to the surface, cools and hardens.
• Weathering, Erosion and Deposition:
• Weathering breaks down rocks into sediment.
• Erosion is the movement of that sediment.
• Deposition is the process where the sediment is
dropped off.
Processes that form rocks:
• Compacting & Cementing:
• Cementation is when sediments are glued together
to form a rock. Pressure packs sediment together,
cementing minerals together.
• Compaction is when sediments are pressed together
through pressure
• Heat & Pressure:
• Heat from magma and pressure from overlying rock
squeezes minerals changing rocks.
Types of Rocks
Igneous Rock
Forms from magma or lava (melted rock on the Earth’s
surface), melted rock.
Granite
Diorite
• When it cools above
ground it cools faster
forming extrusive
igneous rock (ex.
granite).
• When it cools
underground, it cools
slower, forming
intrusive igneous rock
Pumice
Obsidian
Types of Rocks
• Sedimentary Rock
Conglomerate
• Formed from sediment that has become
compacted and cemented together.
• Sediments are small pieces of material
broken off rocks.
• When rocks are deposited in layers and
they are compacted and cemented
together, they form strata (a
layered/striped look).
• Examples - Limestone, conglomerate
and sandstone.
http://www.physicalgeography.net/fundamentals/10f.html
Sandstone
Types of Rocks
• Metamorphic Rock
• Form from other rocks
being heated and put
under pressure.
• Rocks undergo
metamorphosis, not
melting.
• Example - Marble
http://www.physicalgeography.net/fundamentals/10f.html
Gneiss
Marble
http://rst.gsfc.nasa.gov/Sect2/rock_cycle_800x609.jpg
http://www.victoria-sponge.com/media/ROCK%20CYCLE%20diagram%20websm.jpg