| Summary: | New quantitative methods of determining plate motions with respect to the hotspots, and their associated uncertainties are presented. These methods are then applied to Pacific hotspot data and combined with the global plate circuit to make estimates of the Cenozoic motion between Pacific and Indo-Atlantic hotspots. It is found that Pacific and Indo-Atlantic hotspots have little to no resolvable motion, about 3 +/- 6 mm yr-1, since 48 million years before present (Ma), but do show large motions, about 50 +/- 15 mm yr-1, between 48 and 68 Ma. This implies that a global hotspot reference frame for plate motions is attainable, at least since 48 Ma. It is also demonstrated, with the aid of paleomagnetic data that the observed large scale motions prior to 48 Ma are likely, at least in part, a result of unresolved links in the global plate circuit across Antarctica before 48 Ma.
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