I believe that there is some strong evidence that can be adduced in favor of the theory of plate tectonics. Among the more compelling evidences are the presence of lineations on the floor of the Atlantic that more-or-less mirror the outlines of the two continents. There are many correlations that can be made between the geologic and geographic features of the east coast of South America, and the west coast of Africa. Plate tectonics also gives us the only comprehensive explanation for the formation of mountain chains. On the other hand, one must be a bit wary in the face of such a heady theory, not to take it for granted.

Some recent work has cast an interesting shadow on the whole framework of plate tectonics in time. The authors of a paper in Nature in 2001 concerned with the dating of zircons by lead-uranium isotope methods obtained dates of 600 million and 1.6 billion years from a suite of samples from cores alongside the mid-atlantic ridge, in lavas that were expected to give very recent dates according to the plate tectonic theory. Just what the ultimate explanation for these anomalies will be is not clear, but in the present context it probably has more to do with the validity of radiometric dating methods than it does with plate tectonics.

I have cast a model for earth history on the concept of plate tectonics. This document, although tentative, is available at this address .

Ó 2010 Arthur V. Chadwick, Ph.D.