Lost Continent Argoland Still Present But in Fragmented Form [Study]

Argoland, the lost continent, is not really gone. According to a new study, it is still present but is fragmented.

Argoland Found After It Gone Missing?

Geoscientists have long hypothesized that a large chunk of the continent split off from northwest Australia about 155 million years ago and drifted away. The "void" it left behind, a basin known as the Argo Abyssal Plain, located deep beneath the ocean off the coast of northwest Australia, proves this. Argoland, the projected continent, must have drifted off to the northwest and ended up where the islands of Southeast Asia are today, according to the structure of the seafloor. Argoland was called after the abyssal plain.

Geologists Eldert Advokaat and Douwe van Hinsbergen of Utrecht University in the Netherlands have now reconstructed the history of the extinct continent for a new study. They wanted to investigate how they might reconcile the following data, which prompted them to perform the research. They wondered why the fragments were smaller, how the continental crust was lost without a trace, and why the fragments seemed to have left.

The pair said it would be "bad news" if Argoland did vanish by subduction since it would create a significant scientific quandary. It would suggest that entire "lost" continents that were subducted into the mantle may have been overlooked by experts.

They wouldn't have a good picture of what the Earth might have looked like in the geological past if continents could sink into the mantle and completely vanish without leaving a geological record on the surface. Reliable reconstructions of past supercontinents and the world's geography would be nearly impossible to produce.

Over 3,000 miles from western Australia to the north of Papua New Guinea made up the proposed Argoland continent. The Southeast Asian islands were thought to represent the foundation of a solid continent, but only little bits of the continent have been discovered there.

Although these pieces were thought to belong to Argoland, they are incredibly little compared to the supposed continent. In addition, the shards are surrounded by remains of oceanic basins that are far older than the rock record found in the oceanic crust of the Argo Abyssal Plain, dating back to around 205 million years ago. This suggests that the shards left Australia far earlier than Argoland's suggested breakup, which occurred about 155 million years ago.

Advokaat and van Hinsbergen concluded that Argoland is still present but in a fragmented form.

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What Happened to Argoland?

The research showed that when the hypothetical continent of Argoland split off from Australia about 155 million years ago, it wasn't a single, solid mass. Instead, at this time, it seems to have already fragmented into a sort of "archipelago" of numerous small continents with intervening ocean basins.

Other "lost" continents, like Zealandia off the coast of eastern Australia and Greater Adria in the Mediterranean region, went through a similar scenario.

"The breakup of Argoland into the 'Argopelago' was a process that started more than 200 million years ago," the duo said.

The pieces of the continent that made up Argoland can today be found in Myanmar and the islands of Java, Sulawesi, Borneo, and Timor. These islands are all at least partially ruled by Indonesia. In the case of Borneo, Malaysia and Brunei also claim a piece of the island's territory. Meanwhile, East Timor and Indonesia both claim sovereignty over Timor. To put the models they used in their study to the test, the geologists also did fieldwork on many islands.

The study's key finding is that the continental crust did not vanish into thin air. Argoland, on the other hand, was largely made up of oceanic crust, whose remains we also discovered in Southeast Asia. Thus, the geologists said this research contributes to our understanding of Earth processes like subduction.

Subduction is caused by the collision of two tectonic plates, wherein the less dense plate sinks beneath the more dense one.