The discovery of Argoland, the continent that disappeared 155 million years ago

It was one of the biggest unknowns in geology and has now been solved: what happened to the continent of Argoland, which formed 155 million ago and then disappeared.

Geologists from Utrecht University have announced that they have succeeded in making the find “lost continent” that baffled the scientific community for years.

It’s a huge piece of land, approx 5,000 kilometers longthat broke away from Western Australia when that country was part of the former supercontinent of Gondwanaalong with South America, Africa, India and Antarctica.

Scientists knew about its existence long ago because they found traces of the separation of Australia.

They didn’t just see it in fossils, mountain ranges and rocks (where traces of continental division are usually found).

The clearest evidence was enormous hole left by the piece that separated: a basin located in the depths of the ocean, west of Australia, called the Argo Abyssal Plain (hence the name given to the enigmatic missing continent).

But while it is easy to understand how the separation of other continents that were previously united in Gondwana took place – for example, if you look at Africa and South America you will see that they fit together perfectly – what was missing is to discover that piece of land that matched Australia.

Dutch geologists, led by Elder Advokaat, have solved the mystery: it turns out that there is no large landmass called Argoland, because that continent, after splitting off, It fell apart and became an archipelago.

Some of it sank and is today beneath Southeast Asia, in the form of oceanic plates. Although parts of this elusive continent also lie ‘beneath the green jungle of much of Indonesia and Myanmar’, according to research published in the scientific journal Gondwana research.

How they found it

The team of scientists spent seven years testing different computer models to find Argoland’s location.

“We were literally dealing with islands of information and that is why our investigation took so long,” Advokaat explains in a press release.

“Argoland was divided into many different fragments. “That hampered our vision of the continent’s journey,” he said.

Once they understood that Argoland had not been preserved as a solid mass, but had been transformed into a series of microcontinents separated by the ocean floor, Advokaat and his fellow geologist Douwe van Hinsbergen of Utrecht University got to work. identify each sector.

They also came up with a new name that more accurately defines the continent’s current geology: ‘Argopelago’.

Wallace’s line

Putting together the puzzle of this lost continent could also help explain another mystery that intrigues scientists, in this case biologists.

It’s about the call “Wallace Line”. For example, an invisible barrier is known that separates the fauna of Southeast Asia from that of Australia.

Biologists have noticed that animals on both sides of this line, which runs through the south of the Indonesian archipelago (a country made up of more than ten thousand islands), They are very different from each other and do not go together.

Lying west of the line placental mammals such as monkeys, tigers and elephants, which are almost completely absent in the east, where marsupials and cockatoos can be found, animals typically associated with Australia.

“While Sundaland (the Malay Peninsula and the islands of Sumatra, Java and Borneo) is home to ‘Eurasian’ animals, Sulawesi is home to ‘Australasian’ animals, a mix between Eurasian and Australian animals,” Advokaat explained to BBC Mundo .

“This mixing is explained by the fact that the western ‘Eurasian’ part of Sulawesi came into contact with the southeastern ‘Australian’ part of Sulawesi between 28 and 3.5 million years ago, as we show in our reconstruction,” he added to it.

According to the ‘discoverers’ of Argoland, this could be because that continent conquered it its own wildlife when it seceded from Australia and joined Southeast Asia.

This bizarre behavior is not only seen in mammals and birds. Evidence for this has even been found The first human species to inhabit the islands of Southeast Asia respected this invisible barrier.

“These reconstructions are essential for our understanding of processes such as the evolution of biodiversity and climate, or for finding raw materials,” Van Hinsbergen emphasizes. (JO)