Paleomagnetic evidence for a stationary Marion hotspot: Additional paleomagnetic data from Madagascar

The island of Madagascar experienced widespread magmatisin at ca. 90 Ma due to its interaction with the Marion hotspot. Previous palcomagnetic data from igneous rocks in the southwestern and northwestern regions of the island indicated that the Marion hotspot has remained fixed for the past 90 Ma. We report palcomagnetic data from northeastern Madagascar (d'Analava Complex). Samples were collected from basalts, rhyolites, gabbros and a dolerite dyke. Sixty samples from 5 sites yield a paleomagnetic pole at 66.7 degrees S, 43.5 degrees E (A95 = 10.7 degrees) and a grand mean pole (GMP) calculated from 10 different studies covering the entire island of Madagascar falls at 68.9 degrees S, 49.0 degrees E (A95 = 4.4 degrees). This pole translates to a paleolatitude for the Volcan de l'Androy (focal point of the hotspot) at 45.2 degrees + 6 degrees/-5 degrees S compared to the current location of the Marion hotspot at -46 degrees S. Our results confirm, and expand upon, previous studies that argue for the fixity of the Marion hotspot for the past 90 Ma. (c) 2006 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.