is crust mafic or felsic
Making the world better, one answer at a time. Its made up of both. Oceanic crust is mostly mafic magma (basalt) and continental crust is mafic and felsic. The lithosphere also contains the upper portion of the upper mantle which is mostly mafic. The earths crust is 60% Si02 (silicates). Felsic rocks are much more silicate heavy than mafic. So one would assume that the crust is more felsic than mafic. That's just my conceptual thought process so don't take me on my word.