THE PANGAEAN PARADOX: WHERE IS IT?
Version of Record online: 18 DEC 2007
Journal of Petroleum Geology
Volume 5, Issue 2, pages 149–160, October 1982
How to Cite
Crawford, A. R. (1982), THE PANGAEAN PARADOX: WHERE IS IT?. Journal of Petroleum Geology, 5: 149–160. doi: 10.1111/j.1747-5457.1982.tb00502.x
- Issue online: 18 DEC 2007
- Version of Record online: 18 DEC 2007
The postulation of a Precambrian (about 1,300 Ma) expansion of the Earth by Embleton et al. (1981) and Schmidt and Embleton (1981) to explain paradoxical results from palaeomagnetism, by creating a Pangaea asymmetrically disposed on the Earth, produces more problems than it solves. It is preferable to infer that the present pattern of continent and ocean, which appears to be normal (and is probably non-random) derives from a Pangaea which covered the Earth completely or almost completely in the Precambrian and dispersed during the Mesozoic-Cenozoic at a critical stage of persistent, exponentially-increasing and perhaps mildly-pulsatory expansion. In this orderly dispersal, the geometrical relations between the continents were maintained. Data from palaeomagnetism for the period 1,000–200 Ma, although amenable to a consistent orthodox interpretation, may nevertheless be illusory and indicative not of any different continental pattern (in terms of geocentric angles) but of some inner disturbance perhaps related to (or at least concurrent with) large-scale obliquity changes. An earlier critical stage, represented by the ‘Pan-African event’ over the period 750-450 Ma, was the time of the first development of future continental outlines.
This exponentially-increasing expansion permitted retention of continental meridionality from the Precambrian, except for Asia, and preservation in their original orientations of imprints of a global fracture pattern on the continents.
Major Mesozoic-Cenozoic expansion avoids the need for a ‘Tethys Ocean’ (as distinct from an epicontinental Tethys Sea). Precambrian expansion would create such an ocean as an extension of a great and equally artefactual ‘Panthalassa’.