Metamorphic Rocks For Kids
Rocks are made up of one or more minerals. Although different rocks can contain the same minerals, they are sorted into different types of rocks depending on how they were formed.
Metamorphic rocks form when existing rocks are exposed to heat and pressure deep within the Earth’s surface. That’s a pretty neat way of understanding different types of rocks!
Metamorphic Rock Examples
Examples of metamorphic rocks are marble and slate. There are many more with some really weird names like anthracite, quartzite, granulite, gneiss and schist.
What Are Some Other Types of Rocks?
There are three types of rocks: igneous, sedimentary and of course metamorphic rocks.
Metamorphic rocks don’t only form from igneous or sedimentary rocks, but they can also be formed from other metamorphic rocks. Wow, that’s weird.
How are Metamorphic Rocks Formed?
This type of rock is formed under extreme pressure and heat over quite a long time.
Metamorphic rocks are called this name as they always start out as another rock. Metamorphic is a word that literally means to change from one thing to another. There you go…now you know!
When slate forms, some of the clay from the original rock is replaced by a mineral called mica.
During the stage of changing – which is called contact metamorphism – broken down pieces of rock near the Earth’s surface are changed by magma.
During regional metamorphism, another stage of changing, rocks buried deep down in the Earth are changed by magma chambers.
Even though the rock gets really, really hot and is under a whole heap of pressure, it doesn’t melt. Wow, that’s one strong rock.
If it did melt, that would mean that either igneous or sedimentary rocks would form.
Interesting Metamorphic Rock Facts
There are rocks called foliated rocks. This is a type of rock with parallel bands of grain. Wow, that sure is weird.
Then there are non-foliated rocks. This is a type of metamorphic rock that has no bands of grain.
Now this is quite amazing. Do you know marble? Well, it’s a type of metamorphic rock that is made from limestone! Wow.
Schist is a type of metamorphic rock that comes from slate, which is another type of metamorphic rock.
Slate, a metamorphic rock, can form from shale, clay or mudstone.
The Taj Mahal in India is made entirely of different types of marble, a metamorphic rock. That’s really cool.
Marble is quite durable, but it can be dissolved by lemon juice and other acids. No throwing these things at the Taj Mahal then!
Did you know that most of the Earth’s crust is made of metamorphic rock? Well, it’s true!
Words You Need to Know
Igneous Rocks – these are formed through the cooling and then solidifying (becoming solid) of magma or lava.
Sedimentary Rocks – these are formed by sediment that is deposited over time, usually as layers at the bottom of lakes and oceans.
Foliated – this means that something is made up of thin sheets.
Durable – means that something is quite strong and hard to break.
