A cupola is a recess, indentation, or cavity in the ceiling of a

lava tube A lava tube, or pyroduct, is a natural conduit formed by flowing lava from a volcanic vent that moves beneath the hardened surface of a lava flow. If lava in the tube empties, it will leave a cave. Formation A lava tube is a type of lava ca ...

, a kind of cave formation. Cupolas may originate from partial collapse of the ceiling, inflation of the roof by

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

pressure, or from a roofed-over site of a former tube overflow. They can be situated anywhere in a lava tube but are most common in lower-level passages.

References

Volcanic landforms Cave geology {{Volcanology-stub

See also

References