Oldest evidence of 3.3 billion year old earthquake found

Geologists have discovered that the rocks of the Barberton Greenstone Belt are similar to rocks subject to earthquakes and landslides in New Zealand.

Scientists have found signs of some of the earliest known earthquakes in 3.3 billion-year-old rocks. The rocks provided early evidence of plate tectonics, which explains how the Earth's crust is divided into large plates that glide through the mantle. The rocks also point to the conditions that may have prevailed when life first developed.

Geologists made the discovery after investigating the Barberton Greenstone Belt , a complex geological formation in southern Africa.

The Makhonjwa Mountains on the Barberton Greenstone Belt, where scientists found evidence of Earth's earliest known earthquakes. (Photo: Beate Wolter).

According to a new study, just published in the journal Geology, they found that this belt is remarkably similar to much younger rocks in New Zealand that have experienced submarine landslides caused by vertical earthquakes along the Hikurangi subduction zone .

Lead author Simon Lamb, a geologist at Victoria University of Wellington in New Zealand, said: 'The energy released in these earthquakes is immense and it shakes the whole region.'

According to the study, Barberton Greenstone, named for its green color, provides one of the most extensive geological records of Earth from 3.2 billion to 3.6 billion years ago.

Co-author Cornel de Ronde, chief scientist at GNS Science, a research institute in New Zealand, published a partial map of the belt in 2021, revealing a giant jumbled mass that broke away from where they were. formed.

Geologist Simon Lamb sees geology similar to what he has seen along New Zealand's east in 20-million-year-old rocks and recent submarine landslides. Specifically, Great Marlborough – a remnant of the continental shelf that collapsed in submarine landslides – in the Hikurangi subduction zone is very similar to the Barberton Greenstone Belt, according to a statement released by GNS Science.

Off the coast of New Zealand, the Pacific plate is sliding beneath and rubbing against the Australian plate, creating large earthquakes and submarine landslides. During these landslides, rocks formed on land and in shallow water fall into the deep ocean, mixing their original locations.

According to the study, this formation could be the result of thousands of earthquakes over millions of years, with each earthquake shifting the largest blocks. This is actually a record for the duration of the shaking, an ongoing phenomenon in the early Earth.

Earth formed about 4.6 billion years ago and then cooled to become a water world. According to the study, there is no scientific consensus on when plate tectonics began, with the possibility that it occurred before 2 billion years ago. Scientists say there were earthquakes before those explained in the Barberton Greenstone Belt and that they coincided with the origin of life.

Biologists are unsure where, when and how life began on Earth, even though the oldest fossils are dated at 3.7 billion years old. They believe that subduction zones have created the conditions for life and allowed it to exist. Life is born from extreme violence.