Location of Louisville hotspot and origin of Hollister Ridge: geophysical constraints

Abstract

The application of a new geometric technique [P. Wessel, L. Kroenke, A geometric technique for relocating hotspots and refining absolute plate motions, Nature 387 (1997) 365–369] recently pointed to a recent change in the Pacific plate absolute motion and suggested that the Louisville hotspot could now be located underneath the Hollister Ridge, south of the Eltanin fault system. However, the pole that was proposed for the last 3 Ma does not fit the trend of most Pacific volcanic alignments, supporting geochemical evidence [I. Vlastelic, L. Dosso, H. Guillou, L. Géli, H. Bougault, J. Etoubleau, J.-L. Joron, Geochemistry of the Hollister Ridge: relation with the Louisville hotspot and the Pacific–Antarctic Ridge, Earth Planet. Sci. Let. 160 (1998) 777–793] that does not favor a genetic relationship between the Louisville hotspot and the Hollister Ridge. We propose a pole near 57°N, 100°W that reconciles kinematic models with a previously proposed location [P. Lonsdale, Geography and history of the Louisville hotspot chain in the Southwest Pacific, J. Geophys. Res 93 (1988) 3078–3104] for the Louisville hotspot (near a Pleistocene volcano dredged at 50.5°S, 139.2°W) and claim that the Hollister Ridge most probably results from intraplate deformation processes.