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Magma and igneous rocks formed at subduction zones originate due to _______ Question options:?
Magma and igneous rocks formed at subduction zones originate due to _______
loss of volatiles
addition of volatiles
- Anonymous2 months ago
...due to anomalies in the matrix.
- busterwasmycatLv 72 months ago
If I had to give one of those choices as an answer, I would choose D. The devolatilization of the wet rock forming the descending slab causes addition of water and other volatiles to the materials above the slab, and the addition of water, in particular, has the effect of lowing melting points for materials having a broadly granitic composition. In effect, melting occurs because of composition change and not because of any temperature or pressure change.