For many centuries, the existence of a continent was completely unknown to all people. It is hidden under the Pacific Ocean, so it cannot be seen. It is estimated that it was separated from Asia almost 85 million years ago, and over time, more than 90% of that land area was submerged in water.
That continent is called Zealandia, which was named that way by geophysicist Bruce Luyendyk in 1995. It is also known in smaller size as Tasmantis. The smallest part of the land that has survived is what is now made up of the islands of New Zealand and New Caledonia, which is equivalent to 6% of the continent.
Although the possibility of it being called the eighth continent has been discussed for many years, it has not yet been achieved.
In recent years scientists have been able to discover more of this mysterious site in the world. What is known is that it corresponds to a completely unified continental crust, that its extension reaches 5 million square kilometers – which makes it as big as India – and that it was once part of the supercontinent Gondwana.
Now, research published in mid-September in the journal Tectonics allows us to discover new details about the history of this part of the earth.
A team of geologists from GNS Science, led by scientist Nick Mortimer, is aiming to complete the mapping of two-thirds of Zealand and has created a detailed map with the aim of generating greater knowledge about the origin of this continent. In this way, they have added information on three million kilometers of land submerged in the sea, which until now has not been identified.
To continue their study, the specialists described that they dedicated themselves to collecting samples of various rocks from the Fairway Ridge to the Coral Sea, which covers the underwater zone of Zealandia.
Then, they analyzed their chemical composition and dated it. There the geologists discovered that the sandstones are about 95 million years old, some are mixed with granite and volcanic rocks from 130 million years ago and basalts that are more recent than others. rock, because it shows a date of 40 million years ago. ..
All this data, added to information from previous research, helped scientists to create a geological mapping of terrestrial and marine reconnaissance of the entire continent of Zealand, which has been completed.
“The dating of rocks and the interpretation of magnetic anomalies allowed us to map the main geological units of North Zealand. This work completes the marine reconnaissance geological mapping of five million square kilometers of the continent of Zealandia, “they described in the study.
In the past years, GNS Science scientists have carried out other studies in the southern part of Zealand with the same objective: to make geological mapping for land and marine reconnaissance to better understand how this continent works.
A recent Tectonics study also raises what may have been the changes that Zealandia faced over time. According to the Science Alert site, researchers have found some patterns that are similar to West Antarctica, so they believe that Zealandia has suffered a subduction of its plates. This occurs on what is now the Campbell Plateau.
Another big question is how Zealandia achieved a sufficient stretching of its Earth’s crust that resulted in the sinking of most of the continent.
GNS Science scientists suggest that between 80 and 100 years the direction of the stretch varies by up to 65 degrees, so they believe that this is the reason for the cracks that allow sea water to enter, and later , the continent may sink. it is left to be seen what the islands of New Zealand and New Caledonia are.