A Presentation by Elizabeth Devon, Geologist
Talk on March 12th 2025 for the Berwick Civic Society
The talk began by looking for the evidence that the Cheviot Hills were volcanoes. We looked at the geology map and could see a vast area of lavas with granite in the middle. We looked at the types of lavas and realised that they are the type which erupt violently. We then explored the plate tectonic causes of the volcanic activity, some 400 million years ago, when the plates were south of the equator.
Next, by looking at the VEIs (Volcanic Explositivity Indices) of recent and well-documented past eruptions, we concluded that the eruptions on Cheviot were amongst the largest occurring on Earth. We decided that the chances of surviving the eruptions in Berwick were not good. Fortunately, there were only primitive plants on the land at the time but the fish in the sea would have heard the explosions.
Elizabeth was able to present geological data in a way that made it accessible to even the most unscientific member of the audience. We learnt that the clues to Earth’s story are all there beneath our feet for us to read. We came away with a greater understanding of the significance of this knowledge and why we are able to live and work on our piece of the planet at this time.