what causes columnar jointing
Columnar Jointing. Columnar jointing forms in lava flows, sills, dikes, ignimbrites (ashflow tuffs), and shallow intrusions of all compositions. Most columns are straight with parallel sides and diameters from a few centimeters to 3 m.Some columns are curved and vary in width.Columns can reach heights of 30 m. This photo is an early 20th century postcard of the Honeycomb at Giants Causeway.ntablature is probably the result of cooling caused by fresh lava being covered by water. The flood basalts probably damned rivers. When the rivers returned the water seeped down the cracks in the cooling lava and caused rapid cooling from the surface downward (Long and Wood, 1986).