Continental Drift, Geology of the ocean floor and the New Global Tectonics

The theory of Continental Drift is introduced and the similarity of the
shape of the edges of the continents is illustrated from Bullard et. al. and Smith and
Hallam. The Geological similarities among the southern continents and also between
the Caledonian and Appalachian orogens are briefly mentioned.
A short Summary of ocean-floor topography and geology is then given
and extended to the concept of Ocean-Floor Spreading. The supporting evidence
from magnetic anomalies in the oceans, reversals of the earth's magnetic field,
distribution of earthquakes and their focal mechanisms are summarised and their
relations with transform Faults are explained.
The theory of plate Tectonics then described and its implications for the
mechanism of the development of island arcs and mountain belts are very briefly
mentioned. It is pointed out that the application of Plate Tectonics has some of
the geological problems of of the continents such as the Franciscan Melange of
the western U.S.A. and also the history of the Uralides; and that it could be used
to interpret the geology of Iran.