Secrets of the separation process of the ancient supercontinent

In an article published in Geophysical Journal International, Dr. Graeme Eagles of the Department of Earth Sciences at Royal Holloway - University of London revealed how supercontinents once existed with the transfer from continent. other places.

Gondwana is a supercontinent that existed about 500 to 180 million years ago. In the last four decades, geologists have been debating how the supercontinent Gondwana split; Since then, many ideas can be combined into two main hypotheses:

- a hypothesis asserts that the supercontinent separates into many small parts;

- The remaining hypothesis suggests that the supercontinent only breaks into a sufficiently large number.

Dr. Eagles collaborated with Dr. Matthais König of Alfred Wegener Ocean and Polar Research Institute in Bremerhaven (Germany). The two men built a new computer model to prove that the supercontinent split into two parts and that they were too heavy to be interconnected.

Most of the land area in the southern hemisphere including Antarctica, South America, Africa, Madagascar, Australia-New Guinea, New Zealand, Saudi Arabia and even the Indian subcontinent belonging to the Northern Hemisphere is also super continent Gondwana. 250 million years ago to 180 million years ago, the supercontinent Gondwana was part of the only supercontinent Pangea.

The image illustrates the movement of Gondwana over millions of years (Photo: Dr. Graeme Eagles, Royal Holloway - University of London)
Africa: Africa
Antarctica: Antarctica
Myr ago: million years ago

The evidence clarifies that Gondwana began separating 183 million years ago. When analyzing unusual data on gravity and magnetism at some of the first supercontinent Gondwana fault points in the Mozamaca basin and Riiser-Larsen waters off Antarctica, Dr. Eagles and Dr. König reconstructed the path that every segment of the supercontinent Gondwana went when separated.The computer model has revealed that the supercontinent cuts into two large parts, east and west. About 30 million years later, these two parts split apart to create today's continents in the Southern hemisphere.

Dr Eagles said: 'We can say that this process is still ongoing because Africa is slowly splitting along the East African fissure. The previous view is that the Gondwana supercontinent originally split into many small, complicated, unnecessary continents. But it also gave rise to the hypothesis that the inner shell (beneath the Earth's crust), between 2000 and 3000 kilometers long, began the process of cleavage. In this process, the focal point of the inner shells is called a flexible element that separates the supercontinents. Because the supercontinent only splits into a small number of continental disks, it is similar to the types of stratigraphic tectonics that occur in the later part of Earth history - the period of inner shell groups also holds a small part of the role. "

According to the research of Dr Eagles and Dr. König, supercontinents like Gondwana in terms of gravity are not sustainable. They have a very thick crust compared to the oceans, eventually they start to break due to their mass.

Dr. Eagles said: 'Our findings will be a starting point for more accurate, more thorough research on supercontinents. The new research model is questioning the position of India and Sri Lanka in the Gondwana supercontinent in the old model that has been widely used for the past 40 years. The new model suggests that they have a different position when they are associated with the supercontinent. This difference has a great importance to our understanding of the Earth. '