Volcanic Activity in the Channel Islands - Matthew Babcock

    Although the Channel Islands are not currently considered to be volcanically active, there has been past volcanic activity on some of the islands, with Guernsey being the most active of the 8. The eruption that formed the island of Guernsey, which is believed to have occurred around 60 million years ago, was likely a submarine eruption experts say, which means that it occurred on the ocean floor and resulted in the formation of a "volcanic island" as lava and ash built up over time. Today, the island's geology is dominated by igneous rocks, including basalt and rhyolite, which are types of volcanic rock. Guernsey is also the most "geologically diverse" of the Channel Islands, with a lot of rock formations that are evidence of past volcanic activity. One of the most notable examples is the "Basalt Island Formation" which is a series of lava flows that date back to the Cretaceous period, around 130 million years ago. These formations can be seen in various locations around Guernsey, such as Pleinmont Point and Rocquaine Bay.

    Another example of past volcanic activity on Guernsey worth mentioning is the "Hot Rocks Formation" - a set of "dolerite intrusions" that also date back to the Cretaceous period. These intrusions can be seen in various locations around the island, including around the Vale Castle and Vale Pond. In addition to these examples, there are other areas on Guernsey where volcanic activity is believed to have occurred, such as the dolerite formations at Petit Port and the granite outcrops at Icart Point.

    It is important to note, however, that there have been no volcanic eruptions in the Channel Islands for millions of years, and there is no current volcanic activity of any kind in the region. The volcanic activity on Guernsey and some of the other Channel Islands occurred long ago, and the islands are now really only subject to occasional minor earthquakes.

   In conclusion, while the past volcanic activity of the Channel Islands is ancient history, it has had a lasting impact on the islands' geology and landscape. The rocks that make up much of the islands' geology are resistant to erosion, which has contributed to the development of rugged coastlines and rocky cliffs. The volcanic activity has also contributed to the current mineral wealth of the islands, with basalt being used as a building material and a source of paving stones, and rhyolite being used for decorative purposes.

Sources:

https://www.telegraph.co.uk/travel/destinations/europe/united-kingdom/articles/uk-volcanoes/

https://www.bgs.ac.uk/discovering-geology/earth-hazards/volcanoes/

https://en.wikipedia.org/wiki/Channel_Islands

https://www.bbc.com/news/world-europe-18175986

https://www.heritagedaily.com/2018/09/volcanic-map-of-the-united-kingdom/121724

https://www.nps.gov/subjects/volcanoes/prehistoric-and-historic-eruptions.htm