Cornwall and Devon proved to be land mass that exited Europe a few millennia earlier
THE CORNISH have long claimed independence from the rest of Britain, arguing that they are culturally distinct and deserving of devolution.
Now a new study suggests they may have a point – at least geologically speaking.
Geologists at the University of Plymouth have discovered that Cornwall and Devon were once part of the land mass that is now France.
Scientists have for centuries believed that England, Wales and Scotland were created by the merger of Avalonia and Laurentia more than 400 million years ago.
But new research shows the British mainland was in fact formed from the collision of three ancient land masses, including Armorica, which became continental Europe.
The findings, published in Nature Communications, follow an extensive study of mineral properties at exposed rock features across Devon and Cornwall.
They reveal a clear boundary running across the two counties, with areas to the north sharing their geological roots with the rest of England and Wales, but everything south being geologically linked to France and mainland Europe.
The research project’s lead author, Dr Arjan Dijkstra, a lecturer in igneous petrology, said: “This is a completely new way of thinking about how Britain was formed.
“It has always been presumed that the border of Avalonia and Armorica was beneath what would seem to be the natural boundary of the English Channel.
“But our findings suggest that although there is no physical line on the surface, there is a clear geological boundary which separates Cornwall and south Devon from the rest of the UK.”
There have long been human links between France and Cornwall, with Julius Caesar writing of the strong trade contacts between South West England and the area that is now Brittany.
The Cornouaille region of Brittany was named after Cornwall and the two regions spoke a similar language, which has evolved into Cornish and the closely related Breton.
The new revelations could even explain the tin-mining boom in Cornwall, as the metals tin and tungsten – which are abundant in south-west England, but not so evident in the rest of the UK – are also found in Brittany and other areas of mainland Europe.
For the research, Dr Dijkstra and his team visited 22 sites in Devon and Cornwall that were left exposed following geological events such as underground volcanic eruptions. These took place around 300 million years ago and brought magma from depths of 100km to the Earth’s surface.
The researchers took rock samples from each site, then subjected them to detailed chemical analysis in the laboratory using X-ray fluorescence (XRF) spectrometry.
The samples were also dissolved in acid in order to conduct a more intensive isotopic analysis, with scientists examining the levels of two elements – strontium and neodymium – to understand the full history of the rocks. These findings were compared with previous studies elsewhere in the UK and mainland Europe, with the results showing the clear boundary running from the Exe Estuary in the east to Camelford in the west.
“We always knew that around 10,000 years ago you would have been able to walk from England to France,” Dr Dijkstra said. “But our findings show that millions of years before that, the bonds between the two countries would have been even stronger.
“It explains the immense mineral wealth of south-west England, which had previously been something of a mystery, and provides a fascinating new insight into the geological history of the UK.”