Do you think of the Earth as one big solid planet?
Well, it’s actually not, there are loads of different layers to the Earth, similar to an onion, and today we’re going to look at the Earth’s crust which is like the outermost layer of the onion.
The crust is the outermost layer of our planet and is less than 1% of the entire Earth’s size.
There is the crust and then the mantle and they both contain different kinds of rocks which make them different from each other.
The continental crust is the crust that is covered by land.
It’s light in color and is made mostly out of granite.
Above the granite is a sedimentary rock, which is made up of bits of materials and the remains of dead animals or plants. Sounds gross, doesn’t it?
Underneath the ocean is the oceanic crust.
This is made from basalt lava flows, which have come from erupted volcanoes that have taken place over millions of years.
It is very dark or even black and it’s really, really heavy.
Oceanic crust is also made up of iron, oxygen, silicon, magnesium, and aluminum.
The crust is the thin outer layer of the Earth where we live.
When you look at it on a picture it looks really thin in comparison to the other layers, but don’t worry, we won’t be falling through it by accident anytime soon.
The crust can be between 5km thick (in the ocean floor) to around 70km thick (on land where we live called the continental crust).
The oceanic crust is about 8km thick.
The continental crust is solid and the temperature overall is about 22⁰C.
The Different Types of Rock Earths Crust is made of
As we know, the Earth’s crust is made up of different types of rock; here we take a look at each of them to see what they are.
Igneous Rocks – these are rocks that are formed from magma, which is a liquid rock that has cooled and hardened inside the Earth.
Sedimentary Rocks – these rocks form over long periods of time from broken rocks, chemical sediment, and debris.
Basaltic Layer – these rocks are in the oceanic crust and they are rocks that form the deep sea bed floor.
So there are some of the rocks that make up the crust, let’s take a look at a few facts!
Interesting Facts about the Earths Crust
- The crust is deepest in mountainous areas. It can be up to 70km thick here.
- The continental and oceanic crusts are bonded to the mantle, which we spoke about earlier, and this forms a layer called the lithosphere. This layer is cool and rock solid.
- Beneath the lithosphere, there is a hotter part of the mantle that is always moving. This movement splits the lithosphere and causes volcanoes and earthquakes. Wow, so that’s where they come from!
Ever wondered why the ocean floors are so much deeper than land?
Well unbelievably the continents that we live on are thicker and lighter, so they float on top of the mantle. Cool huh?
They are kind of like chunks of ice floating on a lake. Wow, that’s interesting.
So there’s all you need to know about the Earth’s crust! Watch out for more info on the many different layers of the Earth.