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| Titel |
Upper mantle structure beneath the Southern Scandes Mountains and the Northern Tornquist Zone - results from teleseismic P-wave travel time tomography |
| VerfasserIn |
Anna Bondo Medhus, Niels Balling, Bo Holm Jacobsen, Richard W. England, Rainer Kind, Zaher Hossein Shomali, Christian Weidle, Søren Gregersen, Peter Voss, Hans Thybo |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250039272
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| Zusammenfassung |
| Structure and dynamics of the upper mantle is important in understanding timing and
mechanisms shaping prensent day topography and near surface geology.
Debate persists regarding the geological age of the Scandes Mountains. We contribute by
imaging upper mantle structure beneath southern Scandinavia using teleseismic P-wave travel
time tomography (P-tomography).
We include data from mobile stations deployed in projects CALAS, CENMOVE, MAGNUS,
SCANLIPS and Tor. Permanent stations included are those available from the University of
Uppsala, NORSAR and GEUS.
P-wave arrival times generally show differences of up to 1 second across the study
area.
Upper mantle velocities are relatively high in southern Sweden and southern Norway east of
the Oslo Graben. Lower velocities are observed in the Norwegian-Danish Basin
southwest of the Sorgenfrei-Tornquist Zone(STZ) and in the southwestern part of
Norway.
We interpret the southwestern boundary of thick Baltic Shield lithosphere where we observe
the highest horizontal P-wave velocity gradient. Thus, we find the boundary of thick
lithosphere to more or less coinside with the STZ in the southeastern part of the study area,
extending from southern Sweden into the northern part of Jutland. From here it turns north,
passing through the Oslo Graben area to about 60-N then turning northwest, approaching the
Norwegian west coast around 65-N.
Thus, as compared to Baltic Shield, upper mantle velocity is significantly reduced beneath
deep sedimentary basins of Denmark and northern Germany. |
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