Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots.

Where is magma mainly generated?

Magma originates in the lower part of the Earth's crust and in the upper portion of the mantle. Most of the mantle and crust are solid, so the presence of magma is crucial to understanding the geology and morphology of the mantle.

How is magma generated in the earth?

Magma is created at mid-ocean ridges via decompression melting. Strong convection currents cause the solid asthenosphere to slowly flow beneath the lithosphere. The upper part of the lithosphere (crust) is a poor heat conductor, so the temperature remains about the same throughout the underlying mantle material.