3. Igneous Rocks
Can be a single mineral or an aggregate of many
minerals
Created by volcanic activity
Can form on earth’s surface or below it
Oldest Rocks on earth
4. Minerals
Composed of one substance
Can be a single element
Examples:
Halite (salt)
Sulfur
Quartz
Calcite
5. Igneous Rocks Cont.
Coarse Grain Rocks
Intrusive – Formed inside the earths surface
Cooled slowly
Large crystals – Slow cooling allowed the crystal
forming minerals more time to collect
Examples:
Granite
Gabbro
6. Igneous Rocks Cont.
Fine Grain Rocks
Formed at earths surface – above ground or under
water
Cooled very quickly
Examples:
Basalt
Rhyolite
Obsidian – volcanic glass
no crystals due to instant cooling
7. Sedimentary Rocks
Not formed from volcanic activity
Made of other rocks and minerals
Grain size can range from not present to huge boulders
Pieces that make up a sedimentary rock are called
sediments.
9. Clastic Sedimentary Rocks
Made up of rock fragments, shells, or other sediments
cemented together
Can often see or feel the different sediments in the
rock
Examples
Sandstone
Conglomerate
Breccia
10. Non-Clastic Sedimentary rocks
Usually made of one chemical
Can be composed of:
Precipitated minerals in water
Once living plants or organisms
Examples:
Coal
Gypsum
Limestone
11. Metamorphic Rocks
Rocks that have undergone change due to extreme
heat and pressure
The rocks and minerals contained in them do not melt
during this process.
12. Metamorphic Rocks
There are two main types of metamorphic rocks, what
are they?
Stratified
Non-stratified
13. Stratified Rocks
Rocks that have visible bands of minerals
Bands run in lines that resemble layering
Has had extreme pressure applied to two opposite
sides
The bands are minerals that grouped together during
the extreme pressure
14. Examples of Stratified Rocks
Parent Rock Metamorphosed Rock
Granite Gneiss
by Andrew Alden by Andrew Alden
Shale Schist
by Andrew Alden by Andrew Alden
15. Non-stratified Rocks
No rings or bands
Noticeable change from parent rock
Pressure was applied from all directions
Parent Rock Metamorphosed Rock
•Limestone •Marble
•Photo by: Georges Grondin Photo by: Titus Tscharntke