Which the theory of plate tectonics states that the earths crust is composed of many plates that move gradually across the earths surface?
> t
or
> f

D. latin america followed by africa

Magma forms by partial melting of upper mantle and crust. partial melt means that only a fraction of the available material forms a melt, and that the remainder stays solid. the partial melt rises because of its lower density and ascends through he crust. this is so conclusive mean the answer would be magma igneous rocks or balistic magma.