HR: 11:15h
AN: GP22A-04    [Abstracts]
TI: Reconciling hotspot and TPW reference frames within the uncertainties by evolutionary computation of hotspot motion
AU: * O'Neill, C J
EM: cjoneill@rice.edu
AF: Rice University, Earth Sciences, Bldg 16 6100 Main St. Houston, Houston, TX 77005 United States
AU: Mueller, D
EM: dietmar@geosci.usyd.edu.au
AF: The University of Sydney, Earth Sciences, Bldg F05, Sydney, NSW 2006 Australia
AU: Steinberger, B
EM: bernhard.steinberger@ngu.no
AF: Geological Survey of Norway, N-7451, Trondheim, NA 1 Norway
AB: A significant discrepancy exists between TPW and fixed hotspot reference frames in the time period between 90-120Ma. A number of Indo-Atlantic hotspots, including Tristan da Cunha, Great Meteor and Kerguelen, display a significant paleolatitude drift at this time, which cannot be explained by polar wander. However, the degree of motion implied is of a similar magnitude to the uncertainties inherent in the hotspot reconstructions. We present a method for contraining the uncertainties in hotspot reconstructions, and present a model for the motion of the Indo-Atlantic hotspot group based on an interactive evolutionary approach to the inverse mantle convection problem. The hotspot motion is consistent with available paleolatitudinal constraints, and calculated plume conduit tilts are similar to tomographically imaged conduits. We show that fixed and moving hotspot reference frames are not significantly different until 80Ma, and the discrepancy between TPW and hotspot reference can be greatly alleviated for moving hotspots.
DE: 1525 Paleomagnetism applied to tectonics (regional, global)
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2005 Joint Assembly