Wide-angle seismic constraints on hyper-extended crust at the Deep Galicia Margin
Abstract
During the Galicia3D experiment in 2013, we acquired coincident normal-incidence and wide-angle seismic data covering a 64 by 20 km region of hyper-extended continental crust and exhumed mantle on the Deep Galicia Margin west of Spain. The hyper-extended crust is characterised by steeply dipping normal faults soling out onto the low-angle S detachment. Using three-dimensional first-arrival seismic tomography across this region and two-dimensional reflection-refraction tomography along a densely sampled region through this region, we have previously shown that uppermost mantle velocities are reduced where the normal faults intersect with the S detachment, interpreted as the result of hydration. Here we present further analysis of these data using two-dimensional time-domain full-waveform inversion (FWI) and three-dimensional reflection-refraction tomography. These techniques allow us to reduce ambiguities in interpretation of syn-rift sediment, pre-rift sediment and crystalline crust above S, and provide enhanced resolution of variations in hydration beneath S.
- Publication:
-
EGU General Assembly Conference Abstracts
- Pub Date:
- April 2017
- Bibcode:
- 2017EGUGA..19.8898M