Which type of volcano forms low sloping, broad mountains with generally quiet eruptions?

Which type of volcano forms low sloping, broad mountains with generally quiet eruptions?

• A. Shield Volcanoes
• B. Composite Volcanoes
• C. Cinder Cones
• D. Lava Domes

Answer: (A)

The main idea here is how magma viscosity shapes volcano form and eruption style. Low-viscosity lava, like basalt, flows easily and spreads out over large areas instead of piling up high around the vent. This creates broad, gently sloping mountain masses built up by many lava flows that cover a wide footprint. Because the magma can flow freely, eruptions are typically effusive—lava pours out in lava flows that travel far from the vent rather than erupting explosively and ejecting large amounts of ash and tephra. That’s why shield volcanoes fit the description: they form low, wide, dome-like mountains and usually have relatively quiet eruptions. In contrast, composite (stratovolcanoes) have steeper sides and erupt explosively due to more viscous magma trapping gases, while cinder cones are smaller and steeper, built from volcanic fragments ejected into the air, and lava domes form from viscous magma that piles up near the vent and can be quite explosive.

The main idea here is how magma viscosity shapes volcano form and eruption style. Low-viscosity lava, like basalt, flows easily and spreads out over large areas instead of piling up high around the vent. This creates broad, gently sloping mountain masses built up by many lava flows that cover a wide footprint. Because the magma can flow freely, eruptions are typically effusive—lava pours out in lava flows that travel far from the vent rather than erupting explosively and ejecting large amounts of ash and tephra.

That’s why shield volcanoes fit the description: they form low, wide, dome-like mountains and usually have relatively quiet eruptions. In contrast, composite (stratovolcanoes) have steeper sides and erupt explosively due to more viscous magma trapping gases, while cinder cones are smaller and steeper, built from volcanic fragments ejected into the air, and lava domes form from viscous magma that piles up near the vent and can be quite explosive.