Which mechanism increases magma silica content as an oceanic plate subducts beneath continental crust?

💡 Explanation

When an oceanic plate subducts, water released from hydrated minerals lowers the melting point of the mantle wedge. Thus crustal assimilation occurs because as magma rises through the continental crust, it incorporates silica-rich minerals from surrounding rocks, increasing its overall silica content. Therefore crustal assimilation results, rather than other mechanisms which don't directly involve contamination by Si minerals.

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