Melting above a subducting slab produces mafic magma, as described in Exercise 5.10, yet intermediate rocks (andesite, diorite) are common in many subduction zones. Considering the magmatic processes discussed in section 5.4 and the difference between oceanic and continental lithosphere, explain how this intermediate magma forms

The intermediate magma has a heterogeneous structure, since it has a part of Silice, approximately 50-60% to be more exact.

When it turns into lava, it produces rocks like the Andesite and, in the opposite case of its crystallization, it forms rocks like the Diorite.

A comparison of felsic magma is much more viscous.

It is important to clarify that this magma is a type of primary magma, that is to say that they are magmas formed from the fusion of the rocks of the mantle or the crust.

Explanation:

The fusion of these rocks are what would give rise to the intermediate magma, this intermediate magma is a primary magma, like the mafic and felsic.

The primary magmas unlike the derived magmas is the origin or the reason for how they are formed, which is what we write above, derived magmas usually form differently since they are the product of the evolution or changes that magmas undergo primary