Lecture: Cornish cliffs, Alpine peaks and salt intrusions – Geological windows into Earth’s mantle
Speaker:
Entry Fee
Members: Free
Visitors: £5 on the door at BRLSI or book via Eventbrite to access on Zoom
Date and Time
19:30 -
Location
Bath Royal Literary and Scientific Institution, 16-18 Queen Square, Bath BA1 2HN
Lecture Description
The lithospheric mantle, the lower part of the tectonic plates beneath the crust, is made of dense, dark-green peridotite rich in olivine (peridot) and pyroxenes. Despite forming at depths of at least 35km mantle rocks crop out in many places, often occurring as highly altered serpentinite. This talk will focus on some of the processes that lead to exposure of mantle rocks at the surface. Probably the best-known settings in which serpentinite occurs in large volumes is in ophiolite complexes where instead of being subducted, slivers of oceanic crust are thrust up onto the overriding continental margin. Examples of ophiolites exist in Cyprus, Oman and, closer to home, in the Lizard of south Cornwall. I shall also look at some of the ideas emerging from the study of serpentinized peridotite discovered at the feather edges of continental margins, and what these rocks tell us about how continents split apart to form new oceans.
About the speaker: 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.