Scientists collect samples to study the lost continent of Zealandia

It’s not Atlantis, Lemuria, or Mu – about 23 million years ago, the 8th The continent was completely submerged In the ocean, 60 million years after it separated from the supercontinent Gondwana. We’re talking about Extinct Zealandiawhich geologists have only recently described as a continent in its own right, and of which we now have specimens.

The similar geology between New Zealand and New Caledonia was already known to geologists, but after years of exploration and research it was realized that the two archipelagos shared much more. Both lie over the same submerged landmass – we usually think of continents as continuous landmasses, like America or Asia, but in 2017, a submerged landmass joined the group when it was decided Zealandia would be better described as its own continent.

What’s Zealand like?

Most of mainland New Zealand is underwater, about 94%, with the exception of New Zealand, New Caledonia and some smaller islands. There is much to discover about the “new” continent, but we do know that its crust is thinner than its counterparts, although it is thicker than oceanic crust. We also know that its formation occurred when Gondwana separated, when the Earth’s crust thinned and expanded.

However, we do not know the reason for this thinning, which is the subject of the current study by researchers. In a study published in the scientific journal Tectonics, samples dredged from Zealandia were collected to map and model the continent, as well as to search for possible magnetic anomalies. It is believed to be the first continent to have a basement and a sedimentary base Volcanic rocks Trace to the oceanic-continental boundary.

According to researchers, the extensive thinning of the Earth’s crust, which ended with the sinking of the Earth Continental massThey occurred between 100 million and 80 million years ago, perhaps as they expanded in different directions. Now that it is almost completely submerged, there is evidence that Zealandia was once home to a wide range of animals and plants, with pollen spores from land plants and the shells of shallow-water animals having been found on the ocean floor where the extinct continent once stood.

Many species survived continental separation, in which the Gondwana supercontinent was divided between Africa, America, Antarctica, Arabia, Australia, India, and Madagascar. Now that we know that there is another continent in these calculations, many things begin to make sense.

The large geographic changes in northern Zealandia, which is roughly the size of India, help explain the spread and evolution of plants and animals in the South Pacific, for example. Hey The lost continent The “corridor” was that Species were allowed to move from one part of the world to another.

source: Tectonics

Popular on Canaltech: