Publication Date:
2021-03-05
Description:
The first discovery of ultrahigh-pressure coesite in the European
Alps 30 years ago led to the inference that a positively buoyant continental
crust can be subducted to mantle depth; this had been considered
impossible since the advent of the plate tectonics concepts. Although
continental subduction is now widely accepted, there remains
debate because there is little direct (geophysical) evidence of a link
between exhumed coesite at the surface and subducted continental
crust at depth. Here we provide the first seismic evidence for continental
crust at 75 km depth that is clearly connected with the European
crust exactly along the transect where coesite was found at the
surface. Our data also provide evidence for a thick suture zone with
downward-decreasing seismic velocities, demonstrating that the European
lower crust underthrusts the Adriatic mantle. These findings,
from one of the best-preserved and long-studied ultrahigh-pressure
orogens worldwide, shed decisive new light on geodynamic processes
along convergent continental margins.
Description:
Published
Description:
815-818
Description:
7T. Struttura della Terra e geodinamica
Description:
JCR Journal
Keywords:
04.01. Earth Interior
;
04.07. Tectonophysics
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
