Which mechanism causes a shield volcano's broad, gently sloping shape when compared to stratovolcanoes?

💡 Explanation

When low-viscosity lava erupts, effusive eruptions occur because this magma flows readily over long distances, forming broad, gently sloping shield volcanoes characteristic of hotspot volcanism. Therefore, low viscosity lava is responsible, rather than high-silica magma, pyroclastic flows, or tectonic uplift, which involve different volcanic and geological processes.

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