Question

Which is not true of calderas?

a. they generally form over continental hotspots
b. they erupt high-viscosity lavas
c. they are highly explosive
d. they generally produce basaltic lava
e. they result from an emptied or partially emptied magma chamber

Answer 1

The false statement about calderas is that they generally produce basaltic lava, as they often erupt high-viscosity and explosive rhyolitic lava over continental hotspots.

Step-by-step explanation:

The statement about calderas that is not true is that they generally produce basaltic lava (Option D). Calderas can form over continental hotspots and can be highly explosive due to the emptying of a magma chamber.

The Yellowstone hotspot and the Anahim hotspot are examples of continental hotspots that have formed calderas. Calderas typically erupt high-viscosity lavas, which can be more rhyolitic due to their silica content, leading to more explosive eruptions. The basaltic lavas are more commonly associated with oceanic crust and lava plains.