A steep-sided mound that forms when viscous lava piles up near a volcanic vent. Domes are formed by andesite, dacite, and rhyolite lavas.

Domes form when a dome-shaped mass of volcanic rock is too viscous to flow far from the vent. They are often formed on composite volcanoes at the end of an eruption.

Small steep-sided volcano that has been formed by pasty lava that has piled up atop its vent. Domes are typically no larger than 2 to 3 kilometers (1 to 2 miles) in diameter and are composed of silica-rich lavas.

A steep-sided mass of viscous (doughy) lava extruded from a volcanic vent (often circular in plane view) and spiny, rounded, or flat on top. Its surface is often rough and blocky as a result of fragmentation of the cooler, outer crust during growth of the dome.

A steep-sided mound that forms when viscous (thick like honey) lava piles up near a volcanic vent (opening at the surface).

a bulge usually within a volcanic crater, caused by the building up of lava that is too thick (viscous) to flow freely. Often precedes an explosive eruption.

A steep-sided pile of lava formed by the eruption of sticky lava.

A steep-sided mound that forms when very viscous lava is extruded from a volcanic vent.

A lava dome is a dome-shaped mound that is formed around a vent by viscous lava.

A solid bubble shaped cap that forms over a vent when the lava is so viscous that it cannot flow. Gases that form underneath the dome either escape from a side vent, or cause another eruption that will shatter the dome.

a steep-sided, rounded extrusion of highly viscous lava squeezed out from a volcano and forming a dome-shaped or bulbous mass of congealed lava above and around the volcanic vent.

Formed where a steep-sided mass of viscous lava is extruded from a volcanic vent. Domes often have circular bases. Dome surfaces are often rough and blocky as a result of fragmentation of the cooler, outer crust during growth of the dome.

Gas-poor lava forming a steep-sided hill, usually close to an eruptive vent. Examples include Motutaiko Island (Lake Taupo), Mokoia Island (Lake Rotorua), the domes that make up Mount Ngongotaha (Rotorua), etc.