Two billion years ago, tiny marine organisms contributed to the formation of mountains

Microscopic single-celled organisms that float invisibly in the sea may have played a major role in creating some of the largest geological structures on our planet.

Although the formation of mountains is usually associated with the collision of tectonic plates that cause huge slabs of rock to rush upward, a study - published on November 26 in the journal Communications Earth & Environment - showed that this was Originally caused by the abundance of nutrients in the oceans two billion years ago, which was accompanied by the explosion of various types of microorganisms in the oceans, such as plankton, for example.

The study showed that when these plankton die in shallow waters and sink to the bottom, they cause the addition of organic carbon to the Earth's crust, which increases the flexibility of the bottom crust and makes it weaker.

Brittle crust

According to a report published on the "Science Alert" website, John Parnell and Conor Brolly from the School of Earth Sciences at the University of Aberdeen, UK, studied a total of 20 mountain ranges around the world.

This included: the Rocky Mountains in central North America, the Andes, which is the longest continental mountain range in the world and extends along the western edge of South America, and Svalbard in Norway, in addition to other mountain ranges in Central Europe, Indonesia and Japan.

The researchers were able to observe a remarkable synchronization between the increase in the concentration of carbon in the ocean floor crust, and the emergence of mountain chains on the planet.

In a press release published on the University of Aberdeen's website, the researchers explained that "with the high concentration of carbon from bio-carbon added from plankton, the ocean floor crust has acquired a high capacity to deform, in a way that has led to the construction of mountain belts, and thus distinct margins of plate tectonics as we know it." Today".

The changes appear to have begun nearly two billion years ago, in the middle of the Paleozoic Era, when biological carbon from plankton and bacteria began adding exceptionally high concentrations of graphite to the ocean floor rock, making the rocks brittle and more prone to accretion.

Within 100 million years, most mountain ranges formed in these weak slices of the Earth's crust. The researchers also noted that the mountain ranges that have recently emerged follow the same pattern.

Earth and the Biosphere

Although several previous studies have shown that graphite is a necessary component to weakening plate tectonics and forming mountains, they have not been able to determine how this occurs.

Given that all of the 20 mountain ranges the researchers studied recently contained highly concentrated black shale graphite of biological origin, the researchers concluded that marine life is an essential part of this process.

"We can clearly see evidence in northwest Scotland, where ancient mountain roots and the slippery graphite that helped form them can still be found in places like Harris, Terry and Gerloch," says Parnell.

The researchers suggest that a mutation occurred in marine life two billion years ago in response to the Great Oxidation Event, when photosynthetic bacteria began to produce huge amounts of oxidation, capable of supporting new forms of single-celled life, which in turn led to an abundance of marine plankton.

However, mountain formation does not require much biological carbon. On the contrary, only a small proportion of the biomass is sufficient for the edges of tectonic plates to slide under or over each other when they collide.

However, the study showed that the carbon content in mountain ranges formed from the sediments of the ancient era, was higher than 10%, and it exceeded 20% in some cases.

The authors reasoned that "because of the abnormally high carbon content in Paleozoic sediments, more carbon flowed into subduction zones, which led to deformation more easily."

And if the researchers are right, this means that the microscopic single-celled organisms that float invisibly in the sea may have played a key role in creating some of the largest geological structures on our planet.