Estimates of Palaeodiameters of the Earth through Geological Time

Abstract

Palaeozoic palaeopoles deduced from palaeomagnetic data and from the distribution of glacial deposits are in accord for some of the south polar positionst confirming that it was in the north-west of Morocco in the Cambrian. In Upper Permian the pole had moved to the south-east of South Africa, almost in the middle of Antarctica in the Pangaea assembly used here. The Cambrian North Pole, was similarly in Antarctica and migrated to the Verkhoyansk region in the Permian.

Palaeontological data show unequivocally that India was not involved in long distance drift and collision with the northern continents, as advocated by plate-tectonics protagonists. Instead, it existed in its present relationships with the other continents since at least the Cambrian, and may be earlier. The 'Indus Suture' concept is not valid and Chinese geologists, on the basis of their work in the area, are emphatic on the point. Pangaea, thus, existed as a large, composite super-continent comprising the entire existing continental crust, and both the poles were located over this landmass.

The pole positions indicated above go to suggest that in the Upper Permian, the Earth, with the North pole near Verkhoyansk and the South Pole south east of South Africa was 55-60% of its present diameter. The Cambrian diameter, measured similarly, was smaller. For other Palaeozoic periods, the diameter can be similarlyestimated reasonably accurately.

This suggests that the Earth is expanding, and it is probable that the rate of expansion has progressively accelerated through time.