Scientists may have found 2 billion year old birthmarks of earths first supercontinent

Far beneath the city of Dongshen in northern China, we have discovered what may be the 2 billion-year-old birthmarks of Earth’s first supercontinent.

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Tau.Neutrino said:

Scientists may have found 2 billion year old birthmarks of earths first supercontinent

Far beneath the city of Dongshen in northern China, we have discovered what may be the 2 billion-year-old birthmarks of Earth’s first supercontinent.

more…

> At some point in the deep past, plate tectonics began as Earth cooled. When this happened, however, has remained controversial. Dates spanning three-quarters of Earth’s history have been proposed, from the Hadean eon (between 4.5 billion and 4 billion years ago) to the late Proterozoic eon (less than a billion years ago).

The Earth has continued cooling over its lifespan. Hotter temperatures in earlier times mean greater convection and thinner crust, so plate tectonics mush have been more active in the distant past not less active. Whoever claimed the Proterozoic eon needs their head examined. On the other hand, supercontinents may have been rarer in the past, and that’s what they’re looking at here, a supercontinent.

> We studied an area geologists call the Ordos block, which is part of the North China craton, a very stable chunk of the Asian continent that takes in parts of northeastern China, Mongolia and North Korea. In April 2019, we deployed 609 seismic recording stations spaced every 500 metres along a 300-kilometre line. By combining the earthquake data from these stations, we were able to form a detailed picture of Earth’s crust in this area. Beneath the city of Dongsheng, we found a feature called a dipping Moho in which the bottom of Earth’s crust dips from around 35km deep to more than 50km deep over a horizontal distance of only 40km. This dipping structure looks nearly identical to what is found beneath the Himalayan mountains, except it is around 2 billion years old.

Good. Nice map.