A low, oven-shaped mound, common in volcanic regions, and emitting smoke and vapors from its sides and summit.
A rootless spatter cone (fed by lava from within an underlying lava tube) that has a steep sided, inverted cone shape and is formed from an accumulation of pyroclastic materials.
A small spatter cone up to 5 m high which spits out red hot drops of lava.
a conical mound of spatter above a rootless vent--in this case, a break in the roof of a lava tube
a steep-sided mound of spatter above a rootless vent, in this case a former skylight in a lava tube
A small rootless spatter cone that forms on the surface of a basaltic lava flow (usually pahoehoe) is called a hornito. A hornito develops when lava is forced up through an opening in the cooled surface of a flow and then accumulates around the opening. Typically, hornitos are steep sided and form conspicuous pinnacles or stacks. They are "rootless" because they are fed by lava from the underlying flow instead of from a deeper magma conduit.
