Scientists solve mystery of how Giant's Causeway was formed [View all]

[Judi Lynn]

Volcanologists use samples from Eyjafjallajökull in Iceland to recreate famous hexagonal columns in laboratory
Hannah Devlin Science correspondent

@hannahdev
Thu 12 Apr 2018 11.02 EDT

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.

Yan Lavallée, professor of volcanology at the University of Liverpool and lead author, said: “[This] 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.”

To answer the question, Lavallée and colleagues recreated the process in the laboratory using basalt cores drilled from the Eyjafjallajökull volcano in Iceland. The 20cm-long cylinders, gripped by a clamp at each end, were heated to more than 1,000C until they began to soften into lava. The samples were fixed at each end in a mechanical grip and cooled to test at what point they snapped.

More:
https://www.theguardian.com/science/2018/apr/12/scientists-solve-mystery-of-how-giants-causeway-was-formed?utm_source=esp&utm_medium=Email&utm_campaign=Lab+notes+2016&utm_term=271305&subid=25418764&CMP=ema-3242






More images of the Giant's Causeway:

https://images.search.yahoo.com/search/images;_ylt=AwrUieGn6_harkMAmmeLuLkF;_ylc=X1MDOTYwNTc0ODMEX3IDMgRiY2sDZWFlcjdmOWNnbDI5ZyUyNmIlM0Q0JTI2ZCUzRGZFVE9PSzFyWUgzS3VfNWJGaWk4THF3a19jX3JYc19ya1E2azM1dGQ0N2NwM1EtLSUyNnMlM0RkayUyNmklM0RhUld1NUEwY3cxX0t4T1NsM1EyTQRmcgMEZ3ByaWQDU2hnVUpEMUJRbFdiZnh1WFJnVC5RQQRtdGVzdGlkA251bGwEbl9zdWdnAzEwBG9yaWdpbgNpbWFnZXMuc2VhcmNoLnlhaG9vLmNvbQRwb3MDMARwcXN0cgMEcHFzdHJsAwRxc3RybAMxNwRxdWVyeQMgR2lhbnZcyBDYXVzZXdheQR0X3N0bXADMTUyNjI2MjcwOAR2dGVzdGlkA251bGw-?gprid=ShgUJD1BQlWbfxuXRgT.QA&pvid=NuHBjjEwLjLlO2d6WQqJMAJtMjYwMAAAAAC5xiXO&fr2=sb-top-images.search.yahoo.com&p=+Giant’s+Causeway&ei=UTF-8&iscqry=&fr=sfp#id=143&iurl=http%3A%2F%2F2.bp.blogspot.com%2F-WxKqw2k57rA%2FVzn1DijMA8I%2FAAAAAAAAAK8%2FSW9jTswncZI5hH6MT475RWTpgAMvWuOTgCK4B%2Fs1600%2Fgiants-causeway-f.jpg&action=close