Paleomagnetism in Australia: An overview



The pioneering work of John Jaegar and Ted Irving, together with their geochronology colleagues at the Australian National University (ANU), Canberra, resulted in a substantial contribution to the development of modern concepts in geoscience. Paleomagnetism played a major role in this work, providing strong support for the continental drift theory in its early days and, later, much of the data that led to definition of the geomagnetic polarity time scale.

Australia is particularly well suited for paleomagnetic studies in a range of interesting problem areas. Among the most outstanding are

  • Archaean and Proterozoic tectonics and magnetostratigraphy;
  • circum-Pacific terrain studies, notably in the Tasman Fold Belt (the “mountainous” eastern side of Australia) and Australia's active northern margin in Papua New Guinea and Indonesia;
  • effects of deep weathering on paleomagnetic signatures; and
  • southern hemisphere characteristics of the geomagnetic field, e.g., secular variation, nature of reversal transitions

. Precambrian rocks dominate the surface exposure over much of Australia and are probably the most extensive and conveniently accessible of anywhere in the world. The Tasman Fold Belt is a major part of a Paleozoic Circum-Pacific orogenic belt that stretches from the Antarctic Mountains through Australia, New Guinea, and into southeastern Asia. Understanding the macro- and micro-tectonics of this vast region poses a problem whose scale far exceeds that of the corresponding region of western North America.