Scientists have discovered an enormous ancient volcano buried deep beneath Norfolk and Lincolnshire on the east coast of England that erupted with the force of several thousand hydrogen bombs 454.4 million years ago, according to research from the British Geological Survey. The prehistoric blast blew volcanic ash as far away as Scandinavia, forming the massive ‘Kinnekulle tephra’ layer found across modern-day Norway, Sweden, the Baltic region, Belarus, and Poland.
Uncovering the Deep Geological Past of England
This remarkable discovery is reshaping our understanding of England’s deep geological past, according to Dr Tim Pharaoh, a geophysicist at the British Geological Survey and lead author of the study. Researchers first found clues pointing to the hidden volcano in rock samples taken from two boreholes spaced 65km (40.4mi) apart in Norfolk and Lincolnshire. However, the ancient volcanic system likely spanned an area even larger than that initial 65km distance.
The structure did not resemble a traditional mountain. This was probably not a simple, cone-shaped volcano, according to Dr Dan Condon, a research scientist at the British Geological Survey who co-authored the study. Evidence instead points to a large and complex volcanic system containing several cauldron-like hollows, known as calderas, which extended across tens of kilometres above an extensive body of magma.
Did you know? Zircon crystals act as tiny natural clocks. When zircon crystallises from magma, it incorporates uranium into its structure, which over time changes into lead. Scientists tracked this transformation rate, revealing that the material from the prehistoric English volcano and northern Europe’s Kinnekulle tephra originated simultaneously.
Matching Chemical Fingerprints Across Europe
To connect the English bedrock to the ash beds of northern Europe, researchers measured the rate of radioactive decay inside microscopic crystals. Alongside determining their dates, the British Geological Survey research group examined the makeup of the specimens and observed that their chemical signatures corresponded identically.
Trying to estimate the size of eruptions we have not witnessed is like trying to guess the picture on a jigsaw puzzle with only a few bits in place, according to Prof Jenni Barclay, a volcanologist at the University of Bristol who was not involved in the study. The new study finds striking similarities in the age and composition of rocks located hundreds of miles apart, making researchers more certain these pieces are from the same eruption, Barclay noted.
Frequently Asked Questions
Where was the ancient English volcano discovered?
The volcano lies buried deep beneath the counties of Norfolk and Lincolnshire on the east coast of England.
When did the volcano erupt?
According to researchers at the British Geological Survey, the eruption occurred 454.4 million years ago.
How powerful was the eruption?
Scientists calculate that the prehistoric volcano erupted with the force of several thousand hydrogen bombs, sending ash as far as Scandinavia.
What is the Kinnekulle tephra?
It is an enormous bed of volcanic ash originating from this eruption that is still found today across Norway, Sweden, the Baltic region, Belarus, and Poland.
Explore More Deep Earth Discoveries
Want to stay updated on the latest geological breakthroughs and prehistoric findings? Leave a comment below or share this article with fellow science enthusiasts.