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.

• Which ecological outcome occurs when coastal upwelling currents are significantly reduced?
• Which crustal deformation mechanism generates strike-slip faults along a transform boundary edge?
• Which process primarily maintains water balance in endorheic lakes located in arid regions?
• Which effect promotes plankton blooms when coastal upwelling transports deep water towards the surface?
• Which outcome occurs when a barrier island's dune system loses vegetation cover?
• Which risk significantly increases along major river valleys adjacent to volcanic areas following substantial pyroclastic flows?