Scientists may have recently uncovered a glimpse into Earth’s earliest history, and the secret is concealed deep beneath the Pacific Ocean. Led by geophysicist Simon Lamb from the University of Wellington and Cornel de Ronde of GNS Science, the team of researchers believe that this hidden region offers vital clues about our planet’s distant past.
The key to these ancient insights is located in two places in particular: a remote area in South Africa and a part of the ocean floor off the coast of New Zealand. Together, these sites could reveal important information about the early stages of Earth’s formation and development.
Two Connecting Sites
What connects these two distant sites? When considered together, the two locations provide important insights into the early history of Earth. These sites may hold surprising clues about the planet’s formation and the beginnings of life.
The researchers shared that their project started when de Ronde developed a highly detailed geological map of the Barberton Greenstone Belt, an area located in South Africa’s highveld region. This place plays a key role in understanding Earth’s ancient past.
Plate Tectonics and the Barberton Greenstone Belt
“The geological formations in this [Barberton Greenstone Belt] region have proved difficult to decipher, despite many attempts,” the pair explained.
The researchers believe that the rock formations in the Barberton Greenstone Belt challenge the conventional understanding of plate tectonics. However, they believe their recent findings provide “the key to cracking this code,” offering a fresh perspective on how Earth’s early tectonic processes may have operated.
A Strange Seafloor
De Ronde’s geological map uncovered a special piece of ancient seafloor within the Barberton Greenstone Belt, dating back approximately 3.3 billion years, when the Earth was 1.2 billion years old. This discovery offered a rare glimpse into a distant period of Earth’s history.
“There was, however, something very strange about this seafloor,” Lamb and de Ronde noted, “And it has taken our study of rocks laid down in New Zealand, at the other end of the Earth’s long history, to make sense of it.” This connection between the two sites has helped unravel the mystery surrounding the ancient seafloor.
A New Perspective on Earthquakes
The researchers challenge the common belief that early Earth was a molten, fiery mass with a surface too fragile to form rigid tectonic plates—this would mean it was free from earthquakes. They argue that this view of Earth’s early state is inaccurate.
Instead, they propose that the young Earth experienced frequent, powerful earthquakes. These tremors were caused by tectonic plates sliding beneath one another at subduction zones, suggesting a much more dynamic and unstable planet than previously thought.
Relatively Modern Events in New Zealand
When examining de Ronde’s map of the Barberton Greenstone Belt, the researchers noticed that its “jumbled up” rock formations resembled relatively modern submarine landslides observed in New Zealand. This similarity suggested a possible connection between the ancient and more recent geological events.
In New Zealand, these landslides were caused by massive earthquakes along the Hikurangi subduction zone, the country’s largest fault. The bedrock in this area consists of a chaotic mix of sedimentary rocks, similar to the disordered rock layers seen in the Barberton Greenstone Belt.
Forming Rocks in New Zealand
The rock layers off the coast of New Zealand were formed around 20 million years ago on the floor of a deep ocean trench, an area known for frequent, powerful earthquakes. These seismic events played a key role in shaping the rockbed in this region.
By studying how these New Zealand rocks were created, the researchers believe they have unraveled the mystery of the Barberton Greenstone Belt’s unusual formations, drawing parallels between the two sites to explain the geological processes involved.
The Connection Between New Zealand and Africa’s Coasts
The scientists concluded that, similar to its younger counterpart, the Barberton Greenstone Belt is the “remnant of a gigantic landslide containing sediments deposited both on land or in very shallow water, jumbled with those that accumulated on the deep seafloor.” This finding draws a clear connection between the two formations.
In essence, they argue that if the rock layers in New Zealand were shaped by earthquakes, the same process must have occurred in the Barberton Greenstone Belt. This challenges the long-held belief that Earth’s early surface wasn’t capable of sustaining such seismic activity.
Solving Similar Mysteries
Lamb and de Ronde also propose that their findings “may have unlocked other mysteries, too,” noting a significant link between subduction zones and violent volcanic eruptions. This connection opens the door to understanding other geological phenomena tied to Earth’s early tectonic activity.
As an example, they reference the eruption of Tonga’s Hunga Tonga-Hunga Ha’apai volcano in January 2022, which unleashed an explosion equivalent to a “60 Megaton atomic bomb.” The eruption sent an enormous ash plume into space, and over 200,000 lightning strikes occurred within the cloud during the 11 hours following the eruption.
Ancient Boninite Eruptions and Volcanic Events
Additionally, Lamb and de Ronde highlight that “in the same volcanic region, underwater volcanoes are erupting an extremely rare type of lava called boninite,” which offers a unique glimpse into the bizarre kinds of lava that were prevalent during Earth’s early history. This makes these boninite eruptions one of the closest modern examples of ancient volcanic activity.
They further suggest that the significant layers of volcanic ash present in the Barberton Greenstone Belt “may be an ancient record of similar volcanic violence.” This connection hints that explosive volcanic events, similar to those seen today, were likely a regular occurrence during Earth’s formative years.
Formed in Fire
Moreover, Lamb and de Ronde propose that the lightning strikes linked to these volcanic activities might have “created the crucible for life where the basic organic molecules were forged.” This intriguing idea suggests that the intense electrical activity could have played a crucial role in the formation of life’s building blocks.
In essence, they argue that subduction zones, often seen as centers of tectonic turmoil, might have also provided the necessary conditions to ignite the origins of life on Earth. These regions could have been instrumental to not just shaping the planet’s geology, but also in creating the emergence of life itself. It turns out we have a turbulent planet to thank for our existence!
