Long-lost part of Earth that disappeared 20 million years ago has been discovered

Scientists have discovered an 'important piece of the puzzle' that allowed them to reconstruct part of the Earth's crust which disappeared 20 million years ago.

Geologist Suzanna van de Lagemaat and her colleagues at the Utrecht University in the Netherlands have discovered a 'massive and previously unknown tectonic plate' called Pontus.

Whether you swiftly gave up science aged 15 or not, prepare for your jaw to drop:

The team found fragments of old tectonic plates deep in the Earth's mantle' using tomography 11 years ago.

Tomography is 'a powerful method to image the earth's interior in three dimensions using seismic waves from natural earthquakes recorded at stations located at or near the surface around the world,' according to Science Direct.

Finding the fragments led to the team suspecting there had been a massive tectonic plate 'one-quarter the size of the Pacific Ocean'.

Science Direct

The group of geologists then investigated the mountain belts of Japan, Borneo, the Philippines, New Guinea, and New Zealand, Utrecht University's website reports.

The university's website continues: "To [van de Lagemaat's] surprise, she found that oceanic remnants on northern Borneo must have belonged to the long-suspected plate, which scientists have named Pontus."

The north of the island of Borneo is politically divided between Malaysia and Brunei and it's the field work the team did there which formed 'the most important piece of the puzzle'.

"We thought we were dealing with relicts of a lost plate that we already knew about. But our magnetic lab research on those rocks indicated that our finds were originally from much farther north, and had to be remnants of a different, previously unknown plate," van de Lagemaat says.

Science Direct

After discovering remnants of the plate, the team then set about reconstructing it.

When van de Lagemaat systematically reconstructed 'half of the "Ring of Fire" mountain belts from Japan, through New Guinea, to New Zealand that the proposed Pontus plate revealed itself' - including the rocks the team studied on Borneo.

But why is the plate so important?

Science Direct

Well, the university explains finding out about how tectonic plates that 'make up the earth's rigid outer shell' have moved tells us a lot about the planet's geological history.

"The movements of these plates strongly influenced how the planet’s paleogeography and climate have changed over time, and even where to find rare metals," it states.

Oh, and if discovering a lost 'mega-plate' and reconstructing its history despite it being 'notoriously challenging' to do so - as per Science Direct - wasn't impressive enough already, the team's research also revealed 'a single coherent plate tectonic system stretched from southern Japan to New Zealand, and it must have existed for at least 150 million years'.

The study, titled Plate tectonic cross-roads: Reconstructing the Panthalassa-Neotethys Junction Region from Philippine Sea Plate and Australasian oceans and orogens is published in Science Direct.