Why does the scientific community think that Sillandia is the eighth continent, but it is not included in the textbook?

In 20 17, scientists with wide brain holes discovered this continent with an area of 4.9 million square kilometers in eastern Australia and named it "Silantia". The area of Silantia is about two-thirds that of Australia. Different from other continents, 94% of Hirantia is under the Pacific Ocean, just like an "undersea city".

According to research, 60-85 million years ago, 94% of Silantia was separated from Gondwana, Australia, and then sank into the water. Scientists found in their research that the sinking of Hirantia may be related to the birth of the volcanic belt around the Pacific Ocean.

The researchers analyzed the seabed sediments in Hirantia and found that some sediments existed 1 100 million years ago. Through participating painters, it is found that the coral reef ecosystem 35-50 million years ago is very shallow today, which shows that Sillandia was indeed land before these years.

localism

If you don't know the specific location when you are in mainland New Zealand, then New Zealand will know. New Zealand has always been regarded as an island country in Oceania, and 6% of the surface area of Sillandia is New Zealand. The Silantia region is mainly composed of three parts: North Island and South Island of New Zealand and New Caledonia.

On the lower right of the map of Australia, we are neighbors of Australia.

Why do you think West Asia is the eighth continent?

Although most of New Landia Asia is underwater, some geologists believe that New Landia has the characteristics of continental definition and are promoting its certification. AlexandraWitze, who has a background in geology education at MIT, also called Hirantia "the eighth continent" when he released relevant news.

According to our previous cognition, the mainland must have the characteristics of water. But after scientists adjusted the definition of the continent, these characteristics became the following four points:

First, the altitude is higher than the ocean crust; Secondly, there are many kinds of silicate rocks, sedimentary rocks and metamorphic rocks, and the types of rocks are diverse; Third, the mainland is thicker than the oceanic crust; Fourth, the area is more than 6.5438+0 million square kilometers, and the boundary is clear.

According to the characteristics of Sillandia discovered by scientists using satellite technology and seabed Pareto map, it is judged that the conditions for becoming a continent have been met.

Why isn't Sillandia included in the textbook?

Since Silantia has met the requirements of becoming a mainland, why hasn't it been written into the textbook so far?

Hirantia was originally awarded the title of the eighth continent because foreign authoritative news organizations, such as BBC, used the title of the eighth continent. In fact, whether Silantia can become the eighth continent has not been officially certified, and scientists need more substantive time to acquire more knowledge about the Silantia plate.

Moreover, Sillandia's underwater characteristics also challenge people's existing cognition. Only the certification and support of scientists is not enough, but also enough proof is needed to convince everyone to certify Sillandia Asia. So Sillandia Asia was not written into the textbook.

In addition, the land where the plate movement sank is the kerguelen Plateau, which is a large igneous area of submarine volcano and the microcontinent submerged in the South Indian Ocean. It is located about 3000 kilometers southwest of Australia, and its area is almost three times that of Japan. The plateau extends more than 2200 kilometers to the northwest-southeast direction and is located in the deep sea. The hot spot in kerguelen caused by the plateau began about10.3 billion years ago after the disintegration of Gondwana. A small number of plateaus protrude from the sea level, forming Kerguelen Islands, Hede Island and MacDonald Islands. Intermittent volcanic eruptions continue to keep Headland and MacDonald Islands from sinking.

As for Sunda ancient land, Sahur continent, Yellow Sea, Bohai Sea and part of South China Sea, the offshore continental shelf is submerged due to rising sea level, so it does not belong to plate sinking.