Scientists solve mystery of how Giant's Causeway was formed

Volcanologists use samples from Eyjafjallajikull in Iceland to recreate famous hexagonal columns in laboratory

According to legend, the Giant's Causeway was built by the Irish giant, Finn MacCool, as a crossing to confront his Scottish rival. Scientists have an alternative explanation, and for the first time they have reproduced in the laboratory the process through which the causeway's 40,000 near-perfect hexagonal columns were formed.

Geometric columns are seen in a variety of volcanic rocks across the Earth and are known to form as the rock cools and contracts, resulting in a regular array of polygonal prisms or columns. But until now, geologists had been unsure of the threshold at which cooling magma suddenly fractures into a geometric pavement.