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Plate
Tectonics
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Plate
Tectonics
The earth is made of 3 major layers. The inner layer is called the core. It is made of iron and nickel and is about 3500o. The middle layer is the mantle. The mantle is mostly solid rock, but the temperature in the upper mantle is hot enough to melt some rock. This melted rock is called magma. The outer layer that we live on is called the crust. It seems that the crust is solid, but it is not. It is divided into about 20 sections called plates. The plates float on the magma of the upper mantle and slowly move in certain directions.
The plates have been moving for millions of years. About 225 million years ago, the continents were close to each other. This "super-continent" is called Pangea.
25 million years later, the plates had moved so that the continents had seperated, and it looked like 2 huge continents. The northern continent is called Laurasia and the southern continent is called Gondwanaland.
By the Jurassic era, when the dinosaurs walked the earth, the continents looked like this, with South America and Africa still together and North America touching Europe.
65 million years ago, the continents had drifted apart even more.
Today the continents look like this. India has crashed into the continent of Asia, creating the highest mountains in the world, the Himalayas.
What do you think the continents will look like 20 million years in the future? ? ?
Link to Plate Tectonics Hotlist
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