Alpine peaks and salt intrusions – geological windows into deep Earth’s mantle – Jonathan Turner

The blood-red serpentinites exposed at Kynance Cove in the Lizard of south Cornwall are arguably Britain’s most beautiful rocks and they tell a fascinating geological story. Serpentinite is an unusual rock type that forms where seawater circulates through deep mantle rocks, changing their mineralogy from olivines and pyroxenes to amphiboles such as the curiously named lizardite. But Earth’s mantle lies deep beneath the crust – at least 7km below the surface and, on the continents, at least 35km. So how do mantle rocks such as serpentinite come to be exposed at Earth’s surface? The answers to this question have relevance not only for our general understanding of plate tectonic processes but also for oil and gas exploration in ultra-deep water ocean basins such as Brazil and West Africa. This talk looks at some of the settings where mantle rocks are exposed and will discuss the geological processes that lead to their “exhumation”.

Jonathan Turner is a structural geologist and studied the deep structure of the Pyrenees for his PhD. He spent his career in oil and gas exploration, in academia at Birmingham University, and with Nuclear Waste Services.

https://www.jonathanturner.co.uk

Register in advance to attend virtually:
https://us02web.zoom.us/meeting/register/tZAuceCgrjwrHdI7EARmlrqPJvwrSJnkDsnX

Venue:
St Francis Of Assisi RC Church, 110 Warwick Rd, Kenilworth CV8 1HL
https://maps.app.goo.gl/9CGWRNdgFfttDKtd7