Catastrophic Volcanoes May Have Caused Earth’s First Mass Scale Extinction, Annihilating 80% Of Existing Species
Large volcanic eruptions may have led to the first mass scale extinction of life on Earth, destroying nearly 80 percent of the species found then. There have been five mass extinctions on the planet since the divergent evolution of primeval animals 600 million and 450 million years ago. The first such extinction that occurred took place between 488.3 million and 443.7 million years ago.
According to R&D, volcanic activity had caused the third and fourth mass scale extinction. The fifth such event, which also saw dinosaurs disappear from Earth, was the result of an asteroid impact. However, the reason for the first and second mass extinctions was not known.
The first mass extinction took place at the end of the Ordovician period and lasted for nearly 45 million years. This period occurred between the divergence of the Ordovician and land invasion of vascular land plant and animals. The latter included marine animals such as jawless fish, crinoid, brachiopods, orthoceras, sea scorpion, trilobites and corals.
A team of researchers from the Amherst College in Massachusetts and Tohoku University in Japan took sedimentary rock samples from two places located in southern China and North America, respectively. They studied the mercury in the samples and found that the enrichment of the element coincided with the mass extinction in both areas.
"This is the product of large volcanic eruptions because a mercury anomaly was also observed in other large igneous province volcanisms," researcher Dr. David S. Jones said, as reported by India Today.
Incidentally, powerful volcanic eruptions can generate sulfate aerosols in the stratosphere and subsequently cause global cooling. This climate change could have led to the extinction of nearly 80 percent of the species found on Earth at that point. The research team is now examining the second mass extinction to know more about its cause and effects.