What generally happens when subduction-derived magma encounters thick continental crust?
A) most magma reaches the surface with minor modification
B) the magma solidifies in sheeted dikes with a composition of basalt
C) the magma interacts with the crust, forming felsic or intermediate compositions
D) the oceanic crust melts

Question

Quizplus · Accepted Answer

When subduction-derived magma encounters thick continental crust, it typically interacts with the crustal material. This interaction often results in the magma evolving into more felsic or intermediate compositions due to processes like assimilation, where the magma incorporates elements of the continental crust, and fractional crystallization, where different minerals crystallize out of the magma at different temperatures, changing its composition.

What Generally Happens When Subduction-Derived Magma Encounters Thick Continental Crust