Overview
- The Geological Survey of Northern Ireland and the British Geological Survey published a high-resolution timeline this week showing the volcanic activity that formed the Giant’s Causeway took place over about 5.5 million years, roughly eight million years shorter than earlier estimates.
- Researchers used updated geochronology techniques to compress the timescale and improve precision, allowing them to place Northern Ireland flows into a clearer regional sequence.
- The new timeline ties the Causeway’s eruptions to contemporaneous lava flows that built Staffa and Fingal’s Cave and links Northern Ireland volcanism with magmatism in Mull, Rum, Skye, the Faroe Islands and Greenland.
- The Causeway’s roughly 40,000 basalt columns formed when intense fissure-fed lava flows cooled, contracted and fractured into regular columns, a process the study confirms happened within the revised, shorter window.
- By aligning Northern Ireland with the wider North Atlantic Igneous Province, the findings refine models of Paleogene tectonics and volcanism and will guide future mapping, research priorities and public interpretation of the site.