Misplaced Continent Argoland Found Hidden Beneath Jungles

Researchers have uncovered proof of a misplaced continent that lies hidden beneath jungles in Southeast Asia, in response to a examine.

Geoscientists have lengthy suspected that round 155 million years in the past a protracted piece of continent broke off from northwestern Australia and drifted away. The proof for that is the “void” it left behind—a basin, referred to as the Argo Abyssal Plain, that lies deep under the ocean off the coast of northwestern Australia.

The construction of the seafloor right here signifies that the proposed continent—named Argoland after the abyssal plain—should have drifted off to the northwest, ending up the place the islands of Southeast Asia are at present.

A map exhibits the historical past of the “misplaced” continent of Argoland. Geologists at Utrecht College have reconstructed the historical past of Argoland, discovering that it exists in fragments throughout a area of Southeast Asia.
Utrecht College

The proposed Argoland continent prolonged for greater than 3,000 miles from western Australia to north of Papua New Guinea. Researchers have been anticipating to discover a strong continent hidden beneath the islands of Southeast Asia, however no such massive continent has been discovered within the area, solely small fragments.

It was suspected that these fragments belonged to Argoland, however they’re solely a fraction of the scale of the proposed continent. As well as, the fragments are surrounded by remnants of oceanic basins relationship again to round 205 million years in the past—a lot older than the rock file within the oceanic crust of the Argo Abyssal Plain. This means that the fragments drifted away from Australia considerably sooner than Argoland’s proposed cut up round 155 million years in the past.

These older ages had solid doubt on whether or not these fragments represented elements of Argoland. If they didn’t, this raised a query: Did Argoland then fully disappear by a course of referred to as subduction? That is when one tectonic plate slides under one other plate and sinks into the Earth’s mantle, the geologic layer that lies slightly below the crust.

To seek out out, geologists Douwe van Hinsbergen and his colleague Eldert Advokaat of the Netherlands’ Utrecht College have now reconstructed the historical past of the misplaced continent for a examine revealed within the journal Gondwana Analysis.

They instructed Newsweek: “Our motivation to conduct this analysis was to see how we might reconcile this info: Why are the fragments smaller, how did we lose such an space of continental crust with out leaving a hint, and why do these fragments appear to have left sooner than what we all know from the file in Australia?”

If Argoland did disappear by subduction, this is able to be “dangerous information” as a result of it could pose a significant scientific drawback, in response to the 2 geologists. It will point out that researchers have probably ignored whole “misplaced” continents that have been merely subducted into the mantle.

In a press launch, Van Hinsbergen mentioned, “If continents can dive into the mantle and disappear totally, with out leaving a geological hint on the earth’s floor, then we would not have a lot of an concept of what the Earth might have regarded within the geological previous. It will be nearly inconceivable to create dependable reconstructions of former supercontinents and the earth’s geography in foregone eras.”

He went on: “These reconstructions are important for our understanding of processes just like the evolution of biodiversity and local weather, or for locating uncooked supplies. And, at a extra elementary degree, for understanding how mountains are fashioned or for figuring out the driving forces behind plate tectonics, two phenomena which are carefully associated.”

Within the newest examine, although, the geoscientists decided that Argoland continues to be current, albeit in a fragmented type.

The Earth from space
The situation of the misplaced continent of Argoland could be seen within the bottom-right quadrant of the globe’s seen face.
iStock

For the examine, Advokaat and Van Hinsbergen used software program that enabled them to reconstruct the movement of tectonic plates stretching again a whole bunch of tens of millions of years.

This work revealed that the proposed continent of Argoland was not one strong block when it broke off from Australia round 155 million years in the past. As an alternative, it seems to have already damaged up right into a type of “archipelago” of a number of small continents and intervening ocean basins by this level.

This course of is much like the historical past of different “misplaced” continents, equivalent to Zealandia off the coast of jap Australia and Higher Adria within the Mediterranean area.

“The breakup of Argoland into the ‘Argopelago’ was a course of that began greater than 200 million years in the past,” the 2 geologists instructed Newsweek.

The continental fragments that collectively as soon as fashioned Argoland at the moment are present in Myanmar and the islands of Java, Sulawesi, Borneo and Timor. All of those islands are ruled, at the least partly, by Indonesia. Within the case of Borneo, parts of the territory additionally belong to Malaysia and Brunei. Timor, in the meantime, is split between Indonesia and the sovereign state of East Timor. The geologists additionally carried out fieldwork on a number of islands to check the fashions of their examine.

“The primary implication of this analysis is that we didn’t lose continental crust with no hint,” the 2 researchers mentioned. “As an alternative, a big space of Argoland consisted of oceanic crust, whose remnants we additionally present in Southeast Asia. This examine thus helps our understanding of processes on Earth equivalent to subduction.”

They continued: “Most of all, it exhibits that…our reconstructions of Earth’s geography previously will not be lacking main ‘misplaced’ continents. We could need to look a bit, however the stays are nonetheless current within the geological file.”