Very fluid fragments of molten lava ejected from a vent that flatten and congeal on the ground are called spatter. Typically, spatter will build walls of solidified lava around a single vent to form a circular-shaped spatter cone or along both sides of a fissure to build a spatter rampart.

Spatters ejected by Etna's South East Crater, 5.10.1998 (diameters up to several meters). Photo: J. Alean