Carissimi Associati SGI,
Carissimi Soci Società Associate,
su indicazione del Prof. Rodolfo Carosi (Università di Torino e Presidente SGI) vi segnaliamo l'ultimo podcast di Geology Bites (Conversations about geology with researchers making key contributions to our understanding of the Earth and the Solar System):
Di seguito troverete il messaggio dell'ideatore, Oliver Strimpel, e il link al sito web di Geology Bites.
Cordiali saluti,
La Segreteria SGI
Hello, listeners,
I just released a new episode of Geology Bites with Brian Wernicke of Caltech on the Basin and Range Province.
Two things struck me particularly. The first is the sheer scale of the stretching: by reassembling Mesozoic thrust sheets that the faulting had dismembered, Wernicke and his colleagues showed that the Sierra Nevada has moved some 250 km away from the Colorado Plateau in the last 20 million years. The crust beneath Nevada has been pulled out to about twice its original width, and it is still stretching today.
The second is what set it off. For most of the Cenozoic the western margin was being compressed as the Farallon plate subducted beneath it. But the spreading ridge behind that plate was moving eastward, and when the ridge reached the margin, the boundary condition reversed: North America now faced a plate moving away from it. Compression gave way to extension, and the over-thickened crust spread apart.
Listen at geologybites.com, where you'll also find photographs, figures and animations, or wherever you get your podcasts.
I hope you enjoy listening.
Oliver