ARTICLES
How Earth’s Continents became twisted and contorted over
millions of years
On Kangaroo Island this rock, called a zebra schist, deformed from flat marine sediments by being
stressed by a continental collision 500M years ago
Author
1. Dietmar Müller is Professor of Geophysics at the University of
Sydney;
2. Maria Seton is an ARC Future Fellow at the University of
Sydney;
3. Sabin Zahirovic is a Postdoctoral Research Associate at the
University of Sydney.
This article was initially published in ‘The Conversation’ on 9th
May, 2019.
Classical plate tectonic theory was developed in the 1960s. It
proposed that the outer layer of our planet is made up of a small
number of rigid plates separated by narrow boundaries. The
surface of Earth could be viewed as a simple jigsaw puzzle with
just nine large plates and a bunch of much smaller ones.
Map of the Earth’s rigid plates with the major tectonic plates
labelled. Narrow plate boundary zones are the thin black lines.
Created using plate reconstruction software (www.gplates.org).
However, what was glossed over when global plate tectonic
models were first developed was the enormous deformation
experienced by these seemingly rigid plates.
32
SCIENCE EDUCATIONAL NEWS VOL 68 NO 3