Shear-velocity structure of the Tyrrhenian Sea: Tectonics, volcanism and mantle (de)hydration of a back-arc basin
| Autor: | Greve, S., Paulssen, H., Goes, S., van Bergen, M., CRYSTAL2PLATE: How does plate tectonics work: from crystal-scale processes to mantle convection with self-consistent plates, Petrology, Seismology |
|---|---|
| Přispěvatelé: | CRYSTAL2PLATE: How does plate tectonics work: from crystal-scale processes to mantle convection with self-consistent plates, Petrology, Seismology |
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Tyrrhenian Sea
010504 meteorology & atmospheric sciences Mantle wedge tomography 010502 geochemistry & geophysics 01 natural sciences Mantle (geology) Geochemistry and Petrology Lithosphere Asthenosphere Transition zone Earth and Planetary Sciences (miscellaneous) 14. Life underwater Petrology 0105 earth and related environmental sciences Crust surface waves Tectonics asthenosphere Geophysics back-arc basin 13. Climate action Space and Planetary Science Back-arc basin Seismology Geology hydration |
| Zdroj: | Earth and Planetary Science Letters Earth and Planetary Science Letters, 400, 45. Elsevier |
| ISSN: | 0012-821X |
| Popis: | The Tyrrhenian Sea in the Mediterranean formed as the result of roll-back of the Adriatic and Ionian subducting plates. It is mostly underlain by strongly thinned continental lithosphere, but contains two small oceanic basins in the southern Tyrrhenian, the youngest one located just behind the active magmatic arc. Its regional setting with dense station coverage provides a unique opportunity to derive a high-resolution, 3-D shear-velocity model of this back-arc basin and surrounding onshore areas using interstation Rayleigh-wave dispersion measurements. Our tomographic model, extending to a depth of approximately 160 km, displays a pronounced, nearly ring-shaped low shear-velocity zone between 70 and 110 km depth which surrounds the older oceanic Vavilov Basin. The sharp velocity decrease at 70 km depth can be explained by the transition from a relatively dry lithospheric mantle to more hydrous asthenospheric mantle material. The tectonic evolution of the region and the correlation of the low-velocity anomaly with subduction-related volcanism indicate that the low-velocity anomaly reflects hydrous mantle material in (present or former) mantle wedge regions. We suggest that the absence of the low-velocity zone beneath the Vavilov Basin is due to mantle dehydration caused by the creation of MORB crust. Whereas temperature effects may dominate the asthenospheric shear-velocity differences between various back-arc basins, we find that the variations in shear-velocity structure within the Tyrrhenian area are best explained by variations in mantle water content. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect