A plate tectonic reconstruction of the southwest Pacific, 0-100 Ma

Abstract

Southwest Pacific paleogeography has been reconstructed back to 100 Ma on the basis of the hotspot frame of reference. Plate circuits for all key tectonic elements have been determined with respect to the Indo-Australia (I-A), Antarctica, and Pacific plates, using hotspot trails on the India, Australia, and Pacific plates to constrain the motions of all the plates. Paleo-locations of rifted continental margins, oceanic plateaus, subduction zones, and marginal basins have been reconstructed for the Southwest Pacific in a series of palinspastic maps that are thought to closely portray the tectonic development of the Southwest Pacific during the last 100 m.y. Successive periods of convergence are shown occurring along five different paleo-subduction zones. Episodes of basin formation are shown occurring along the western and southwestern margins of the Pacific Plate and along the eastern and northeastern margins of the I-A Plate from the Late Cretaceous to the present. Seamount chains are also shown developing over the Tasmantid, Lord Howe, Louisville, and Samoa hotspots. -from Authors