A new theory, issued by Canadian geologists at the University of Calgary, says that the great extinction occurred at the boundary between the Permian and Triassic – and dubbed the Dead Sea because of its magnitude – was caused by an accumulation of mercury in the planet’s ecosystems.
The catastrophic event, occurred in the last 250 million years, were killed almost all species of marine life and much of the land. It was the worst extinction in Earth’s history and its causes are a matter of dispute among experts.
Have been suggested as causes, climate change, an asteroid collision, volcanism, sudden release of chemicals in the marine floor, changing ocean currents and others.
Geologists from the University of Calgary believe that a major cause of extinction was sudden rise of mercury in water and atmosphere, great quantity of mercury from volcanoes, during a phase of intense volcanism that passed Earth in that period.
Today it is widely accepted theory that numerous and intense volcanic eruptions would have caused burning Permian coal deposits from the crust, leading to the release of huge quantities of carbon dioxide and other toxic chemicals.
The authors believe that those substances, mercury, a highly toxic metal, may have played a role.
Mercury levels were age permiene extinction, researchers estimate, more than 30 times greater than that caused by volcanic eruptions today. The ocean’s natural ability to maintain chemical balance was then exceeded, resulting in massive mercury poisoning of most living things.
However, scientists have warned that such high concentrations of mercury are seen, sometimes, and today, the waters around some metallurgical plants, where aquatic life is adversely affected.
Information about the great Permian-Triassic extinction are, they say, a warning on the consequences of massive pollution generated by industrial activity intense contemporary times.
Andreea Weed
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