Thread: I need help with the earth's crust

I don't really know how to explain this but how did the earth's crust form I guess. I know that the earth was a shitstorm of magma and lightning and the magma was cooled to form the tectonic plates but how would the plate be shaped, what would/could have cooled the magma, what would the terrain be like, and how would the have moved. Any help or hell even speculation would be much appreciated.

Props for describing the early Earth as a 'shitstorm." That's the best scientific description, ever.

Originally Posted by Casmo82

I don't really know how to explain this but how did the earth's crust form I guess. I know that the earth was a shitstorm of magma and lightning and the magma was cooled to form the tectonic plates but how would the plate be shaped, what would/could have cooled the magma, what would the terrain be like, and how would the have moved. Any help or hell even speculation would be much appreciated.

Cooling of a hot body in space takes place by radiation, from the surface. So the surface would have cooled before the interior. Also, decay of radioactive elements would have helped to keep the interior of the Earth hot - a process that continues.

The temperature difference led to convection within the Earth, which is the source of the motion that drives plate tectonics.

Fractionation occurred, whereby the lighter minerals tended to float upward and the heavier ones to sink down towards the centre. This is how the Earth came to have a core that is rich in iron and nickel, while the mantle and surface rocks are rich in magnesium and aluminium, respectively.

The solid "skin" that would have formed at the surface due to the faster cooling would have been dragged by the convective motion and would have cracked. The blocks thus formed would have been the first tectonic plates.



Eventually,

Originally Posted by exchemist

Originally Posted by Casmo82

I don't really know how to explain this but how did the earth's crust form I guess. I know that the earth was a shitstorm of magma and lightning and the magma was cooled to form the tectonic plates but how would the plate be shaped, what would/could have cooled the magma, what would the terrain be like, and how would the have moved. Any help or hell even speculation would be much appreciated.

Cooling of a hot body in space takes place by radiation, from the surface. So the surface would have cooled before the interior. Also, decay of radioactive elements would have helped to keep the interior of the Earth hot - a process that continues.

The temperature difference led to convection within the Earth, which is the source of the motion that drives plate tectonics.

Fractionation occurred, whereby the lighter minerals tended to float upward and the heavier ones to sink down towards the centre. This is how the Earth came to have a core that is rich in iron and nickel, while the mantle and surface rocks are rich in magnesium and aluminium, respectively.

The solid "skin" that would have formed at the surface due to the faster cooling would have been dragged by the convective motion and would have cracked. The blocks thus formed would have been the first tectonic plates.



Eventually,

I would add that there are theories involving impacts of "cold" bodies which started plate tectonics, and added crustal materials.

Thanks!