New Zealand scientists have found evidence of the planet's first major earthquakes, preserved in rocks that are now more than three billion years old.
According to the study published in the Journal of Geology, New Zealand experts studied some of the oldest geological records, preserved in the Barberton Greenstone Belt in South Africa, where rocks from this region were deposited approximately 3,600 million years ago.
In those rocks, they found evidence of plate tectonics and some of the first large earthquakes on the planet.
The authors of the research, Simon Lamb and Corneille de Ronde, explained that after years of observations, they discovered that they were looking at the remains of giant underwater landslides, consisting of irregular masses of volcanic rock, sandstone, conglomerates and the remains of ponds. Of bubbling mud and ancient seabeds that once remained in the depths of the ocean.
They also found that the Barberton Belt stones resemble rock formations that form in the relatively “young” 20-million-year-old Hikurangi subduction zone off the east coast of New Zealand. In that region, the Pacific plate dips beneath the Australian continental plate.
They said places like that could generate large earthquakes and underwater landslides.
Although many stones were analysed, the key to their discovery was a small piece of folded and highly fractured rock in the Hikurangi subduction zone, called the Great Marlborough Conglomerate, experts explained.
“Based on similarities to underlying rocks in New Zealand, the Barberton greenstone belt shows the characteristic features of a subducting margin periodically shaken by large earthquakes,” the New Zealanders noted.
With this evidence, it can be said that about three thousand and 300 million years ago, seismic subduction already existed; They concluded that this is one of the first known evidence of a large-scale earthquake, or such events in general.
“Award-winning alcohol trailblazer. Hipster-friendly internetaholic. Twitter ninja. Infuriatingly humble beer lover. Pop culture nerd.”