Scientists reconstruct Gondwana – supercontinent that explains changes on Earth 500 million years ago

Chinese and international scientists have, for the first time, discovered numerous buried fragments of "lost continents" – parts of Gondwana – and reconstructed the "Greater Gondwana" supercontinent. According to Science and Technology Daily, a partner of TV BRICS.

The research was carried out by a team led by researcher Wang Tao from the Institute of Geology at the Chinese Academy of Geological Sciences. The scientists created a global database of igneous rocks and isotopes with geographical coordinates, drawing on the "Deep Time – Digital Earth" (DDE) programme. They developed technologies for extracting sample coordinates from ancient texts. The work is based on more than 25,000 neodymium isotope measurements from Asia, Central Europe, North America and Australia.

Isotopic mapping has revealed that numerous Precambrian fragments of the crust lie buried deep within the young orogenic belts. These are the "lost fragments" of Gondwana, which drifted, accreted and were buried following its breakup. Once "reassembled", Gondwana’s area increased to 80 per cent of the continental crust – exceeding the 75 per cent threshold. It thus ranked alongside Pangea and Rodinia.

"We used specialised technologies to extract coordinates and locations from ancient texts, extending our research from Asia to the whole world. [...] We named it 'Greater Gondwana', confirming that it was a true supercontinent," said Wang Tao.

The peaks of the formation and break-up of "Greater Gondwana" coincide with global changes that occurred 500 million years ago.

The transition period from the Ediacaran to the Cambrian (around 550–500 million years ago) is considered one of the most mysterious stages in Earth’s history. The planet experienced a shift in mantle dynamics, fluctuations in sea level and atmospheric composition, changes in the chemistry of seawater, and the mass emergence of multicellular animals – the beginning of the "Cambrian explosion of life".

Global changes are usually explained by cycles of supercontinent formation and break-up. By the classical definition, a supercontinent must cover at least 75 per cent of the area of the continental crust. Pangaea and Rodinia meet this criterion but did not exist 500 million years ago. Gondwana – the most likely candidate for that period – occupied only around 64 per cent according to traditional reconstructions and did not meet the criteria for a supercontinent.

The discovery came as a surprise: the team had initially been working on a database and the deep geology of the Asian continent.