Scientists have made an exciting discovery: they found a missing part of Earth that “vanished” about 155 million years ago when a piece of Western Australia broke away from the continent.
This chunk of land, named Argoland, was believed to have disappeared entirely, but new evidence reveals it fractured into fragments hidden beneath the ocean, under the many islands of Southeast Asia. This revelation sheds light on how continents can change over time, helping scientists piece together Earth’s geological history and the puzzle of how the world’s continents have shifted and formed as we know them today.
What is known
Scientists had knowledge of a 5,000 km landmass known as Argoland because it created a massive gap in the ocean floor, called the Argo Abyssal Plain. One idea was that this land might have completely disappeared, sinking into the Earth’s molten layer beneath the crust where tectonic plates meet, much like what happened to another “lost” continent, Greater Adria, which was as large as Greenland and separated from Italy.
However, Greater Adria left signs of its existence in rock layers that later became mountains in Southern Europe, but there were no similar signs for Argoland in Southeast Asian mountains. Recently, researchers found fragments of this continent hidden beneath the many islands in the region, indicating it broke apart as it moved, rather than staying as a single piece. This discovery was published in the scientific journal Gondwana Research on Thursday (the 19th).
“If continents [could] dive into the mantle and disappear entirely, without leaving a geological trace at the earth’s surface, then we wouldn’t have much of an idea of what the Earth could have looked in the geological past,”– Dowe Van Hinsbergen, a professor at the University of Utrecht and co-author of the study.
By excavating rock layers from the islands of Southeast Asia, including Sumatra, Borneo, Sulawesi, and Timor, Professor Van Hinsbergen and lead author Eldert Advokaat combined their findings with computer simulations of tectonic and continental movements.
The results suggest that around 250 million years ago, Argoland began to fracture and fragment, with its pieces now hidden beneath the ocean depths, just below the thousands of islands in the region.
“We were literally dealing with islands of information, which is why our research took so long. We spent seven years putting the puzzle together”– Dr Advokaat to the English newspaper Metro
The puzzle that Advokaat and Van Hinsbergen solved fits seamlessly between the neighboring geological systems of the Himalayas and the Philippines, adding another chapter to the Earth’s long history of continental puzzle pieces.
About 230 million years ago, when dinosaurs first roamed the Earth, the continents were once part of a single supercontinent named Pangaea. Over time, it gradually separated, reshaping the world like chess pieces, ultimately forming the Earth’s current geography, as explained by scientists.