An international team of researchers has just published in the journal ' Tectonics ' a detailed map of Zealandia, the 'lost' continent that separated from the supercontinent Gondwana between 79 and 83 million years ago. Today, Zealandia's 94% is submerged, and most of the still visible 6% is in what we know today as New Zealand. The existence of this hidden continental mass, whose area is 4.9 million square km, was revealed in 2017 by a team of geologists, who already proposed that Zealandia should be considered the eighth continent of the Earth. (In the Anglo-Saxon world it is considered that the Earth has 7 continents: Asia, Africa, North America, South America, Antarctica, Europe and Oceania). Today, six years later, it is still debated whether Zealandia is really a continent in itself, or if, on the contrary, it is a fragment of another larger continent. Be that as it may, Zealandia has already become an important part of the fossil record, since tens of millions of years ago numerous species of birds flourished there. The fact that most of Zealandia is underwater has made its study very difficult and is the reason why there have been significant inconsistencies in the different maps prepared so far by different groups of scientists. The new study, however, has managed to build the most detailed map of Zealandia yet. To do this, the researchers thoroughly studied collections of rocks and sediments taken from different parts of the ocean floor. Most of the samples were collected by drilling, while others were obtained from the coasts of the numerous islands in the region. "Basalts, sandstones and pebbles were analyzed and dated," the authors write in their article. The sandstones are from the Upper Cretaceous (about 95 million years old) and contain granite and volcanic pebbles from the Lower Cretaceous (130 to 110 million years old). The basalts are from the Eocene (approximately 40 million years old). MORE INFORMATION news Yes Astronomers, on the warpath against satellite constellations: “The sky is also the heritage of humanity” news No They sequence a strange cancer that spreads through the sea among cockles Together, all the samples allowed the team to create their map with a level of detail that is unprecedented. As the researchers themselves write, "land and marine reconnaissance geological mapping of the entire 5 million square kilometer continent of Zealandia is now complete."
