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Silicic Magma 

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Granite USGSSilicic magmas are those with a high percentage of silica, over 65%, granite and rhyolite come into this category. Granitic plutons will crystallise slowly and larger crystals will grow.Continental crust is largely composed of silicic rocks. Indicative minerals are

Within the magma flow patterns caused by convection currents align the crystals. Silicic magmas occur in subduction zones beneath continental crust,continental collision where fractional crystallisation occurs. This where lighter minerals float to the top of the magma chamber and more dense Fe/Mg minerals sink to the bottom.