Comparisons of the Hawaiian and Louisville volcanic chains: Implications for frames of reference and processes causing hotspot motion (Invited)
Abstract
Of the many volcanic chains on the Pacific plate, only two have a demonstrable long-lived (>70 million-year- long) age progression: the Hawaiian-Emperor chain of the northwestern Pacific and the Louisville chain of the southwestern Pacific. Paleomagnetic data, plate circuits, sediment facies and geodynamic modeling indicate rapid southward motion of the Hawaiian hotspot during creation of the Emperor Seamounts, with a dramatic change in the rate of motion near the time of the great bend in the chain (ca. 47 Ma). Several mantle motion processes can explain these characteristics, including mid-mantle tilt toward a paleo-spreading center (Tarduno et al., Science, 2009). The oldest part of the Louisville chain may have also been formed close to a spreading ridge axis. The Louisville track has a more general curvature, and estimates of the past motion of the hotspot have been hindered by uncertainty in the present hotspot location. Notwithstanding this uncertainty, we use revised plate circuit reconstructions, geometric considerations, and paleomagnetic bounds to better understand processes responsible for creation of the Louisville track. We also compare these observations on Late Cretaceous-Paleogene hotspots and their motion with observations on mid-Cretaceous hotspots.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMGP24A..01T
- Keywords:
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- 1525 GEOMAGNETISM AND PALEOMAGNETISM / Paleomagnetism applied to tectonics: regional;
- global;
- 3037 MARINE GEOLOGY AND GEOPHYSICS / Oceanic hotspots and intraplate volcanism;
- 8157 TECTONOPHYSICS / Plate motions: past;
- 8415 VOLCANOLOGY / Intra-plate processes