A TEAM of scientists from the University of Liverpool has made a breakthrough into how the unusual Giant’s Causeway rock formations were created.
According to legend, the causeway was created by Irish giant Finn MacCool throwing chunks of the Antrim coast into the sea to build a route to Scotland.
He planned to fight Scottish giant Benandonner but fled when he saw how large he was.
However MacCool’s wife disguised him as a baby, with the Scot reasoning that if the baby was that size, the father must be massive.
The scientific explanation meanwhile is that the rocks were formed when cooling magma from fissure eruptions cracked.
Until now however, it was unknown at what temperature the magma cooled to form the spectacular stepping-stones.
'We have found the answer'
Recreating the lava cooling process, geologists from the University of Liverpool showed that the rocks fracture when they cool about 90 to 140˚C below the temperature at which magma crystallises into a rock, which is about 980˚C for basalts.
This means that the unique basaltic rock formations at the Giant’s Causeway were formed around at 840-890˚C.
Yan Lavallée, Liverpool Professor of Volcanology who headed the research, said: “The temperature at which magma cools to form these columnar joints is a question that has fascinated the world of geology for a very long time.
“We have been wanting to know whether the temperature of the lava that causes the fractures was hot, warm or cold.
“I have spent over a decade pondering how to address this question and construct the right experiment to find the answer to this question.
“Now, with this study, we have found that the answer is hot, but after it solidified.”
The findings could have tremendous applications for both volcanology and geothermal research.
Understanding how cooling magma and rocks contract and fracture is central to understanding the stability of volcanic constructs and how heat is transferred in the Earth.
We still prefer the giant story though.
