National Geographic has just published a new article that takes a closer look at the mysterious eighth continent Zealandia, or Te Riu-a-Māui.
The idea of the eighth landmass presented itself as early as the mid-’90s, where Zealandia, a continent almost the size of Australia is submerged with New Zealand its only part to exist above sea level. “Continents are sort of like icebergs,” says study author Keith Klepeis, a structural geologist at the University of Vermont. “What you see at the surface is not really the full extent of the beast.”
Analyzing tiny crystals of zircon collected from the few islands of Zealandia that stick out from the water, it was determined that this lost continent is a lot older than first imagined — over a billion years old. This finding is some of the first bits of evidence that support the continent theory as most continents contain a stable base core of rock known as a craton. The oldest form of continental crust that was previously discovered dated back to just 500 million years. Another sign is that most oceanic crust contains high levels of magnesium and iron-packed rocks, however, the seafloor around New Zealand is made up of silica-rich rocks that are commonly found in continental crust.
While this is further evidence that supports the idea of the eighth continent, Zealandia’s samples, when compared to other major continents, still pale in comparison to the three billion-year-old rocks found in Asia, Australia, North America, Africa, South America, Antarctica, and Europe. Those that wish to learn more can head over to Nat Geo for the full article.