Geologists Find Ancient Connection between England and France

The findings are published in Nature Communications and 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 north of it sharing their geological roots with the rest of England and Wales but everything south being geologically linked to France and mainland Europe.

Among other things, scientists believe the research explains the abundance of tin and tungsten in the far South West of England – metals also found in Brittany and other areas of mainland Europe, but not so evident in the rest of the UK.

The research’s lead author, Lecturer in Igneous Petrology Dr Arjan Dijkstra, 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.”

For the research, Dr Dijkstra and Masters student Callum Hatch (now working at the Natural History Museum) 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 100 km to the Earth’s surface.

Credit: University of Plymouth