What are the layers of the earth?

Crust, Mantle, Core (Outer and Inner)

Crust is the thinnest layer. Its thickness varies, for example the crust in ocean or oceanic crust has it thickness of only about ##8## ##km## while in the continental crust it has a depth of up to ##32## ##km##. It is composed of O, Si, Al, Fe, Ca, Na, K, Mg, Ti, and H.

After that, there is a boundary discovered by Andrija Mohorovicic which is named after him. The Mohorovicic Discontinuity or sometimes known as the Moho.

The next one is the mantle which is about ##2900## ##km## in depth. This makes up about ##80 %## of 's volume and ##68## ##%## of the its mass. It composed mainly of Si, O, Fe, and Mg.

The core:Outer core which has a depth of ##2250## ##km## is made of liquid Iron and Nickel. It surrounds the Inner core which has a radius of ##1300## ##km##. It is very dense. It is the innermost layer and is made of solid Iron and Nickel.

http://paleogeology.blogspot.com/2008_11_01_paleogeology_archive.html