Explain why a rhyolitic lava flow is more viscous than a basaltic lava flow
What will be an ideal response?
Answer: Viscosity is dependent primarily on temperature and silica content. The more silica in the magma, the greater the viscosity. Since rhyolitic flows are high in potassium, sodium, and high silica content (~70%) they have a much higher resistance to flow. Basaltic flows have a much lower silica content (~50%). Applying heat to a fluid makes the substance more fluid thus increasing its mobility.
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