ELSEVIER Earth and Planetary Science Letters 164 (1998) 31–40 Location of Louisville hotspot and origin of Hollister Ridge: geophysical constraints Louis Ge ´li a,L , Daniel Aslanian a , Jean-Louis Olivet a , Ivan Vlastelic a , Laure Dosso b , Herve ´ Guillou c , Henri Bougault a a De ´partement des Ge ´osciences Marines, IFREMER, B.P. 70, 29280 Plouzane ´, France b CNRS-IFREMER, BP 70, 29280 Plouzane ´, France c Centre des Faibles Radioactivite ´s, CEA=CNRS, 91198 Gif=Yvette, France Received 30 July 1998; accepted 2 October 1998 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. Ge ´li, 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 57ºN, 100ºW 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 50.5ºS, 139.2ºW) and claim that the Hollister Ridge most probably results from intraplate deformation processes.  1998 Elsevier Science B.V. All rights reserved. Keywords: hot spots; Louisville Ridge; intraplate processes 1. The debate Because the supply of magma for building vol- canoes along the 4300 km-long Louisville seamount chain declined sharply after 25 Ma and was almost totally interrupted after about 11 Ma, the question of the survival and the present-day location of the Louisville hotspot has been a long-term subject of debate ([1,2]) of critical importance, related to the L Corresponding author. questions of absolute plate motions and hotspot fix- ity. In the early seventies, it was suggested [3,4] that the Louisville Ridge was an extension of the Eltanin Fault System (EFS). But Clague and Jarrard [5] pointed out the copolarity of the Louisville Ridge with the Emperor and Hawaiian seamounts, and Mol- nar et al. [6] noted that the topography of the ridge more closely resembled that of a linear seamount chain than a fracture zone. From the shallowing of the Pacific–Antarctic spreading center (with water depth soundings as shallow as 140 m recorded by 0012-821X/98/$ – see front matter  1998 Elsevier Science B.V. All rights reserved. PII:S0012-821X(98)00217-9