columnar jointing

columnar jointing

[kə′ləm·nər ′jȯint·iŋ]
(geology)
Parallel, prismatic columns that are formed as a result of contraction during cooling in basaltic flow and other extrusive and intrusive rocks. Also known as columnar structure; prismatic jointing; prismatic structure.
References in periodicals archive ?
The textbooks used in such classes ascribe the formation of columnar jointing to the volume change (contraction) of flows or shallow intrusions as they cool from the top down (e.g., see [1]).
Spry, "The origin of columnar jointing, particularly in basalt flows," Geological Society of Australia, vol.
These are examples of columnar jointing, solid rock divided into prismatic columns by contraction as the lava flow solidified (Devil's Postpile is the greatest example in the West).
Photo: Fractured block of basalt lava along Burton Creek trail shows columnar jointing