The Three Different The Three Different Types of Rocks:Types of Rocks:
•Igneous
•Metamorphic
•Sedimentary
Where Do Rocks Come From?Where Do Rocks Come From?
• Where do you see rocks?
• Mountains
• Canyons
• Riverbeds
• All rocks are all made of minerals.
• As a matter of fact, rocks are made up of 2 or more minerals.
The Rock CycleThe Rock Cycle
• The rock cycle is an ongoing process that never stops
• There are three different types of rocks: Igneous, Metamorphic, and Sedimentary
• With melting, heat/pressure, and weathering/erosion rocks change into different types of rocks
• Rocks are always changing
Igneous Rocks Igneous Rocks
• The word Igneous comes from the Latin word Ignis, which means Fire.
• Igneous Rocks come from the magma inside of a volcano
• There are two types of igneous rocks:
• Extrusive • Intrusive
Igneous Rocks (Cont.)Igneous Rocks (Cont.)
• Extrusive igneous rocks are formed when a volcano erupts
• The magma will spill all over the surface and cool, this is an extrusive igneous rock
• An intrusive igneous rock is formed when magma doesn’t reach the surface
• Instead, it forces its way into cracks and spaces between other rocks already inside the Earth and turns solid before ever reaching the surface
• Magma that never makes it to the surface turns solid slowly, because it takes it a long time to cool inside the hot Earth
Types of Igneous Rocks Types of Igneous Rocks
• Some examples of igneous rocks are obsidian, pumice, scoria, and granite.
Metamorphic RocksMetamorphic Rocks
• Metamorphism means “to change”
• Normally when we think of metamorphism, we think of caterpillars changing into butterflies
• Through heat and pressure an igneous rock turns into a metamorphic rock
Metamorphic Rocks (Cont.)Metamorphic Rocks (Cont.)
• Marble is a type of metamorphic rock
• It is formed limestone, which is an igneous rock
• The Taj Mahal in India was built of all marble
Types of Metamorphic RocksTypes of Metamorphic Rocks
• Some other examples of metamorphic rocks are schist and gneiss.
Sedimentary Rocks Sedimentary Rocks
• Sedimentary rocks can be formed from many different ways
• Sedimentary rocks are worn down by wind and rain and are washed downstream where they settle at the bottom of rivers, lakes and oceans.
• Eventually, with the pressure of everything above the sediments a sedimentary rock is formed!
• Some of the ways that sedimentary rocks come from are:– Layers of other rocks– Dead animals/plants– Sand
Types of Sedimentary RocksTypes of Sedimentary Rocks
• Some types of sedimentary rocks are gypsum, conglomerate, shale, sandstone,
and limestone.
SummarySummary
• The three different rocks are: igneous, sedimentary, and metamorphic
• There are two types of igneous rocks: intrusive and extrusive
• Igneous rocks come from the magma inside of volcanoes
• Metamorphic rocks “change” with heat and pressure • Sedimentary rocks are formed from layers of other rocks
(at the bottom of lakes/rivers/oceans), dead animals/plants, or sand.