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| Titel |
Seismic anisotropy of the mantle lithosphere beneath the Swedish National Seismological Network (SNSN) |
| VerfasserIn |
T. Eken, J. Plomerova, R. Roberts, V. Ludek, V. Babuska, H. Shomali, R. Bodvarsson |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020247
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| Zusammenfassung |
| Body-wave analysis - shear-wave splitting and P-travel time residuals - detect anisotropic
structure of the upper mantle beneath the Swedish part of Fennoscandia. Geographic
variations of both the splitting measurements and the P-residual spheres map regions of
different fabrics of the mantle lithosphere. The fabric of individual mantle domains is
internally consistent, usually with sudden changes at their boundaries. Distinct back-azimuth
dependence of SKS splitting excludes single layer anisotropy models with horizontal
symmetry axes for the whole region. Based upon joint inversion of body-wave anisotropic
parameters we instead propose 3D self-consistent anisotropic models of well-defined mantle
lithosphere domains with differently oriented fabrics approximated by hexagonal aggregates
with plunging symmetry axes. The domain-like structure of the Precambrian mantle
lithosphere, most probably retaining fossil fabric since the domains’ origin, supports
the idea of the existence of an early form of plate tectonics during formation of
continental cratons already in the Archean. Similarly to different geochemical and
geological constraints, the 3D anisotropy modelling and mapping of fabrics of the
lithosphere domains contribute to tracking plate tectonics regimes back in time. |
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