A revised reconstruction of the southern continents

Authors

  • E. J. Barron,

  • C. G. A. Harrison,

  • W. W. Hay


Abstract

A variety of different reconstructions of the southern continents have been proposed. This is largely a result of the lack of sufficient geologic and geophysical data to constrain their palaeopositions. Specifically, oceanic magnetic anomalies prior to the Late Cretaceous are of generally poor quality, and there is a lack of exposed geological section on Antarctica. A revised reconstruction of the southern continents, based on the 2000-m contour, is proposed which includes the salient features of previous reconstructions but also considers data from several critical areas. The Falkland Plateau is included as defined by the 3000-m contour. To prevent overlap and satisfy geologic constraints, the Antarctic Peninsula is placed to the western side of South America adjoining the Andean province and with Antarctica as a single unit. On the basis of geologic evidence, Madagascar is placed in a southerly position adjacent to Mozambique. The Seychelles are included as a continental fragment. Australia is shifted 250 km to the west with respect to Antarctica to produce a better geologic fit. A palinspastically reconstructed India is adjacent to western Australia and is fitted to a morphologically similar section of Antarctica. The Lord Howe Rise and Campbell Plateau are considered as two separate continental fragments. Although our revised reconstruction is controversial in some respects, it does remove many of the geologic inconsistencies present in earlier models.

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