This is the thinnest layer of the Earth, and it is often described using terms like "oceanic" or "continental."
What is the Crust?
100
We are living in this Eon right now, and it is about 541 million years old - is also means "visible life."
What is the Phanerozoic Eon?
100
About 541 million years ago, there was a massive "explosion" of life, marking the end of the Proterozoic Eon.
What is the "Cambrian Explosion?"
100
If there was an earthquake, scientists can pinpoint this based on the main focus and seismic activity of the quake.
What is the Epicenter?
100
This is a large slab of rock, sometimes up to 65 km thick, which moves around on top of the Asthenosphere.
What is a Tectonic Plate?
200
This section of the Earth is as hot as the surface of the Sun, and scientists theorize it is a solid ball of Iron and Nickel.
What is the Inner Core?
200
This is the Era in which we live, qualified by large visible mammals.
What is the Cenozoic Era?
200
Starting as far back as 2.7 billion years ago, algae and bacteria in the oceans started photosynthesizing the sun's rays - pumping this into our atmosphere.
What is Oxygen?
200
This is the name we give to liquid rock - found underneath the crust and in the mantle, it helps push and move the tectonic plates around.
What is Magma?
200
A hypothetical super-continent that connected all land masses - supported by the fossil record.
What is the Pangaea?
300
This layer lies between the mantle and the core, and scientists think it is made of up Iron and Nickel - but it is more fluid and less hot.
What is the Outer Core?
300
Early on, in the Hadean Eon, a large planetoid struck the earth and subsequently created this.
What is the Moon?
300
This animal was one of the first "complex" species of life to walk around on the Earth, even though most of them lived in the ocean.
What is a Trilobite?
300
If you live on a fault line between two tectonic plates, you should expect to have a lot of these, either nearby or often. They are simply a result of the hot magma moving around below the earth's crust.
What are Volcanoes? What are Earthquakes
300
When the great Pangaea split apart 175 million years ago due to shifting tectonic plates, it created these.
What are Continents?
400
This is the thickest layer of the Earth - and it is often described like "toffee" which moves around under the surface of the Earth.
What is the Mantle?
400
This era means "Old life," and it ended with one of the largest mass-extinctions known to us.
What is the Paleozoic Era?
400
Scientists believe that this substance was formed in the Archean Eon, as it rose to the surface of the Earth; one theory is that it arrived from falling meteors.
What is water? What are the Oceans?
400
This is a very hot cloud of ash, lava fragments and glass fragments ejected from the crater of a volcano.
What is Pyroclastic Flow?
400
This is the name given to a large crack or split between two large, rocky plates of the Earth's crust.
What is a Fault?
500
This is a subdivision of the Mantle, and it is responsible for moving the tectonic plates around on the surface of the Earth.
What is the Asthenosphere?
500
This Eon means "Early Life" and it was dominated by small life forms that lived in the ocean - thankfully they also created much of the oxygen we breathe!
What is the Proterozoic Eon?
500
These early forms of "plants" and "microbial mats" are considered some of the oldest forms of life - and we have fossil evidence of these dating back to 3.7 million years ago!
What is a Stromatolite?
500
It is believed that during the Hadean and Archean Eons, this was formed from volcanoes spewing out tons of ash - and later it was used for photosynthesis. Without it, we would definitely not be here!
What is the Atmosphere?
500
When there is a large earthquake, and a massive shift in a fault line between two tectonic plates - it can cause one of these.