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Lithospheric architecture from amphibious AlpArray data across the Ligurian Basin.
Dannowski, Anke , Thorwart, Martin, Kopp, Heidrun , Caielli, G., de Franco, R., Grevemeyer, Ingo , Lange, Dietrich , Wolf, Felix Noah , Crawford, W. and Paul, A. (2020) Lithospheric architecture from amphibious AlpArray data across the Ligurian Basin. [Invited talk] In: GEO Utrecht 2020. , 24.08.-26.08.2020, Online-Konferenz .
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Abstract
The Ligurian Basin is located north-west of Corsica at the transition from the western Alpine orogen to the Apennine system. The Back-arc basin was generated by the southeast trench retreat of the Apennines-Calabrian subduction zone. The opening took place from late Oligocene to Miocene. While the extension led to extreme continental thinning little is known about the style of back-arc rifting. Today, the seismic events indicate the closure of this back-arc basin. To shed light on the present day crustal and lithospheric architecture of the Ligurian Basin, active seismic data have been recorded on short period ocean bottom seismometersin the framework of SPP2017 4D-MB, the German component of AlpArray. An amphibious refraction seismicprofile was shot acrossthe Ligurian Basininan E-W direction from the Gulf of Lion to Corsica. The profile extends onshore Corsica to image the necking zone of continental thinning. Local seismicity was recorded on broad band ocean bottom seismometers over a period of 8 month. The majority of the refraction seismic data show mantle phases at offsets up to 70km. The arrivalsof seismic phases were picked and inverted in a travel time tomography. The results show acrust-mantle boundary in the central basin at ~12km depth below seasurface. The mantle shows rather high velocities >7.8 km/s.The crust-mantle boundary deepens from ~12 km to ~18 km within 25 -30 kmtowards Corsica. The results do not map an axial valley as expected for oceanic spreading. However, an extremely thinned continental crust indicates a long lasting rifting process that possibly does not initiated oceanic spreading before the opening of the Ligurian Basin stopped. In the centre of the Ligurian Basin, a cluster of 15 seismic events with magnitudes lower than 2.5 occurred in the upper mantle in a depth of 10-15 kmbelow the seismic Moho. The fault plane solutions indicate reverse faulting and a convergence in NW-SE direction.
Document Type: | Conference or Workshop Item (Invited talk) |
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Keywords: | lithospheric, architecture, amphibious, AlpArray, Ligurian Basin |
Research affiliation: | OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-GDY Marine Geodynamics Kiel University |
Projects: | AlpArray |
International?: | Yes |
Date Deposited: | 18 Dec 2020 13:17 |
Last Modified: | 18 Dec 2020 13:17 |
URI: | https://oceanrep.geomar.de/id/eprint/51343 |
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