ABSTRACT
Domes are formed when lava is too viscous to flow as it emerges from the vent, but accumulates and solidifies there in a bulbous mass. They are amongst the smallest, rarest and yet most striking and easily recognizable of the major landforms produced by lava emissions. Although they are much less common than cinder cones, it has been calculated with admirable precision that 217 domes have been formed in the past 10000 years. They are rarely more than 250m in height or 1 km broad and have steep convex sides and no true craters. Domes are commonly built by rhyolitic, dacitic or trachytic lavas, extruded at relatively low temperatures of about 900°C or 750°C.
