An historical perspective of the early palaeozoic APWP of Gondwana: New results from the early Ordovician Black Hill Norite, South Australia

Abstract

While paleomagnetic pole paths and the palaeo-distribution of the continents is reasonably well understood for the past 200 Ma, there is an urgent need for more reliable Palaeozoic palaeomagnetic poles, especially from the Gondwana continents. The distribution of continents and the disposition and convergence of their margins is an important consideration in conceptual models of terrane accretion. Some continental distributions suggest only small oceans between Laurentia and Gondwana throughout the Palaeozoic, while others suggest a wide oceanic separation existed in the Devonian-Carboniferous. Current thoughts on the Gondwana Palaeozoic pole path may be grouped into, the autochthonous school, the allochthonous school and the Kanimblan overprinting push. The pole position from the Black Hill Norite, South Australia, suggests that some Australian Cambrian pole positions which plot nearby may be Early Ordovician overprints.