Transform and rift structure of Paleogene crust near Resolution Ridge, Tasman Sea, southwest New Zealand
Multibeam bathymetry, seismic reflection, magnetic anomaly, and gravity anomaly data show that most of the Resolution Ridge System is Tasman Sea oceanic crust, deformed by Eocene rift faulting associated with the initiation of the modern Australia‐Pacific plate boundary. Resolution Ridge, the most e...
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Veröffentlicht in: | Geochemistry, geophysics, geosystems : G3 geophysics, geosystems : G3, 2008-07, Vol.9 (7), p.np-n/a |
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Sprache: | eng |
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Zusammenfassung: | Multibeam bathymetry, seismic reflection, magnetic anomaly, and gravity anomaly data show that most of the Resolution Ridge System is Tasman Sea oceanic crust, deformed by Eocene rift faulting associated with the initiation of the modern Australia‐Pacific plate boundary. Resolution Ridge, the most eastern ridge of the system, is inferred to be continental crust that was plucked from the southwest corner of the Campbell Plateau during Eocene rift propagation. Rift propagation proceeded through sequential northward steps between weak points in the lithosphere: young fossil spreading centers, fracture zones, and the western margin of the continental Campbell Plateau. Fracture zones guided the large‐scale geometry of the rift, but there is not always a close surface correspondence between transform and rift faults. This may be because transform faults were subvertical, whereas rift faults evolved to be moderately dipping. The very good correspondence of fracture zones, rift faults, and magnetic anomalies from the Resolution Ridge System with their conjugates southwest of the Campbell Plateau allows precise prerift reconstruction of the Australia‐Pacific plate boundary at a time (circa 48 Ma) of significant global plate reorganization and profound change in Pacific plate motion. This precise plate reconstruction better constrains plate motion chains that connect the Pacific and Indo‐Atlantic hemispheres, thus contributing to debate of global scientific issues such as what caused the bend in the Emperor‐Hawaii seamount chain. |
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ISSN: | 1525-2027 1525-2027 |
DOI: | 10.1029/2007GC001887 |