yr8 - metamorphic rocks
TRANSCRIPT
Metamorphic rocks are formed when high temperature and/or high pressure alter existing igneous and sedimentary rock.
Metamorphic rocks can also be formed from existing metamorphic rocks.
We can now complete our rock cycle!
The changes due to the high heat and pressure can be physical and/or chemical.
It can result in the formation of minerals not seen in igneous or sedimentary rocks.
• Regional metamorphismMetamorphism over a large area
• Contact metamorphismOccurs in rocks that come into contact with hot magma as it pushes through the mantle and crust.
Minerals in metamorphic rocks can become squashed into layers.
The rock may develop layers or bands in a process
called foliation.
The amount of banding depends on the amount of heat and pressure.
The bands in a rock are not always straight. Pressure can squash and crumple them, causing the bands to be wavy.
Very hard, suited for building work such as walls and floors (gneiss, quartzite, marble)
Split into flat sheets for floors and roofs (slate)
Sculptures, easy to cut and carve (marble)
To make glass, high silica content (quartzite)
Jewelry, rare and semi-precious gemstones (garnet, diamond, sapphire etc.)
Hardest natural substance, drill bits, saw blades (diamond)
Putting it all together How do Igneous Rocks Form?
How do Sedimentary Rocks Form?
How do Metamorphic Rocks Form?
Putting it all together How do Igneous Rocks Form?
Cooling of Magma or Lava to form solid Rock
How do Sedimentary Rocks Form? Weathering and Erosion forming Sediments which are
Compacted and Cemented
How do Metamorphic Rocks Form? High Temperature and Pressure forming new minerals
and creating Foliation
Putting it all together What are the two types of Igneous Rocks?
What are the two types of Weathering?
What are the three types of Sedimentary Rock?
What are the two types of Metamorphic Rock?
Putting it all together What are the two types of Igneous Rocks?
Extrusive and Intrusive Igneous Rocks
What are the two types of Weathering? Physical and Chemical Weathering
What are the three types of Sedimentary Rock? Clastic, Chemical and Organic
What are the two types of Metamorphic Rock? Contact and Regional