Sea floor spreading in the Tasman Sea: a Lord Howe rise ? eastern Australian reconstruction

Abstract

New finite poles have been calculated for the Tasman Sea based on both pre-existing magnetic data and recently released Australian Bureau of Mineral Resources magnetic data. The pole positions are more southerly than previously calculated; the stage pole positions imply that strike slip motion in the northern Tasman Sea was concurrent with accretion in the southern Tasman Sea during the early stages of opening from anomalies 33 to 32. Progressive northward movement of the stage poles from anomaly 32 time reflects the increasing development of spreading ridges and corresponding reduction in strike slip motion in the northern Tasman Sea until accretion was active throughout the entire basin from anomaly 30 time until its cessation at anomaly 24 time. Many of the characteristic features of the southeastern Australian margin, including its steep slope, its narrow width and scarcity of sediments, all difficult to reconcile with previously postulated rifted models, are more consistent with the present model of margin development.