Which phenomenon causes arc volcanism when an oceanic plate subducts beneath a continental plate?

💡 Explanation

When an oceanic plate subducts, hydration-induced melting occurs because water released from the subducting plate lowers the mantle's melting point, resulting in magma formation and arc volcanism. Therefore, hydration melting is the main cause, rather than decompression, friction, or radiogenic heating which are less significant factors in this process.

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• Which outcome increases proximal fault stress when stick-slip behavior occurs?
• Which mechanism creates arid conditions around 30 degrees latitude within Hadley cells?
• Which effect is directly intensified when El Niño-Southern Oscillation (ENSO) causes a temporary reversal of the Walker circulation?
• Which mechanism creates natural levees bordering a mature alluvial river?