# Where do the electric charge carriers for the current for earth's magnetic field come from?

I have some trouble trying to understand, why streams and convections in the outer liquid earth core, coriolis forces etc. would create an electric current?
Because you probably need an electric potential first and what then is the cause of the electric potential?
Is it perhaps a property of the earth mantle to have regions that are polarized?

• Perhaps caused by tiny initial magnetic matter where nobody knows where this comes from? – Marijn Oct 13 '16 at 9:53