Assertion: caldera | /r/MadeOf | the collapse of land
Facets:
value: usually
type: TEMPORAL
value: following a volcanic eruption
type: TEMPORAL
Source sentences:
text: The article opens with: "A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption.
text: A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption.