A column of igneous rock formed by congelation of lava in the conduit of a volcano and later exposed by the removal of surrounding rocks.
A vertical intrusion with the geometry of a volcanic pipe. An erosional remant of a volcanic pipe.
The solidified magma that originally filled the vent or neck of an ancient volcano and has subsequently been exposed by erosion.
See volcanic pipe.
a cylindrical-shaped landform standing above the surface created by magma solidifying in the vent of a volcano
a plug of basalt that fills the throat of a volcanic cone
A massive pillar of rock more resistant to erosion than the lavas and pyroclastic rocks of a volcanic cone.
The solidified material filling a vent or pipe of an inactive volcano. This hard igneous rock may resist erosion better than the mountain mass originally encompassing it and eventually stand alone as a column, tower, or crag.