ANTIGONISH, Nova Scotia, May 23 (UPI) -- Canadian-led geologists have found continents break along pre-existing lines of weakness created when land chunks attach to a larger continent.
Although the continents have split, drifted and merged many times throughout Earth's history, geologists until now haven't understood the mechanism behind the moves.
The study, led by J. Brendan Murphy of St. Francis Xavier University in Antigonish, Canada, is reportedly the first to provide an explanation for the breaking patterns of continental plates, and uses the formation of an ocean about 500 million years ago to demonstrate that principle.
"We asked the question, 'Why do oceans open where they do and why does a continent choose to break where it does?'" said Damian Nance, Ohio University professor of geological sciences and co-author of the study.
There have been six major continental assembly and breakup events, about 500 million years apart. Currently the Earth is in a breakup cycle in which the Atlantic and Indian oceans are opening, Nance said.
Geologists had long suspected break lines were created by continental collisions but the study is the first that proves the theory.
The research is reported in the journal Geology.