Some problems in current concepts of continental drift

Abstract

Evaporites (gypsum, anhydrite, halite, etc.) of all ages, Proterozoic to the present, have been plotted on world maps. Without exception, 95–100% of the evaporites of each age, by volume and area, occupy areas which today are the earth's dry wind belts. This implies that the wind-circulation patterns of the lower astmosphere have not changed for 1,000 million years. This cannot be true unless the present position of the earth's rotational pole, ocean basins, and continents have also remained essentially unchanged since Middle Proterozoic time. Additional evidence corroborates this conclusion. 1. (1) The present horse-latitude (desert) belts of the Northern and Southern Hemispheres, as shown by the stratigraphic record, have occupied the same approximate positions during the same length of time. The widths of the two horse-latitude belts have fluctuated, but the mean positions have been constant. This suggests great latitudinal stability through time. 2. (2) The evaporate zones of the earth since Middle Proterozoic or earlier time have been symmetrical about the present equator and, therefore, symmetrical with respect to the present rotational axis. 3. (3) Since Late Silurian time, two coal zones, one north of the evaporite zone and the other south of it, have maintained a similar symmetry. 4. (4) In any reconstruction of Gondwanaland, Laurasia, or Pangaea, tillite deposits (e.g., Late Ordovician and Permo-Carboniferous tillites) are in the centers of the supercontinents. This is a physical impossibility because the central parts of the supercontinents are 3,000–4,000 km from the nearest ocean moisture source. Glaciers require abundant moisture (1,000 mm plus per year) for initiation and growth. In all current Laurasia-Gondwanaland reconstructions, not even one-tenth of this amount of moisture could have reached the supercontinents' interiors. 5. (5) The same argument applies to the extensive coal deposits of interior Gondwanaland and Laurasia, except that 1,500–2,000 mm of annual rainfall is required. 6. (6) An argument repeatedly raised in favor of drift is that large trees could not have grown in polar regions. Plots of coal deposits on widely accepted Gondwanaland-Laurasia reconstructions show that dense forests of Permian and Carboniferous ages grew at the Permo-Carboniferous pole, and that thick evaporite deposits (up to 2,000 m thick) were deposited within 15° of the Permian pole (as determined from paleomagnetic studies). We conclude that continental drift (by many mechanism) and polar wandering should be subjected to large-scale reevaluation. Our studies show that, since Middle Proterozoic time, the “new global tectonics” are not applicable and that they introduce major, unexplained inconsistencies into geology and geophysics.