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In the era in which life came about, the Earth could almost no sushi.
Ancient Earth was a little like the blossoming planet we know. Once land was collected in supercontinents, washed by global by the ocean. And in some periods it might not remain at all – about paleogeologists Benjamin Johnson and Boswell Wing (Boswell Wing) write in a new article published in the journal Nature Geoscience. Their study confirmed previous data on that for ages in the history of the young Earth, water covered it entirely.
Initially, scientists were studying the climate of ancient Of the earth. A suitable indicator of ocean temperature can serve isotopic composition of oxygen in water. Lighter molecules containing ordinary oxygen-16, evaporate more easily. Therefore, with growth temperatures and increased evaporation accumulate heavier molecules with oxygen-18. Interacting with mineral rocks, they keep their tracks in them, allowing geologists to reconstruct climate of distant eras.
Johnson and Wing did this work in the northwest. Australia, in the Pilbara region, where rocks come to the surface about 3.24 billion years old. This is an extremely important period: it is worth recalling that life arose shortly before this time and then she was taking her first careful steps. Various hypotheses associate her appearance with “black smokers” at the bottom of the oceans, and with periodically drying ponds.
However, if the traces of the ancient “smokers” are preserved in the same Australian rocks then with drying ponds 3.24 billion years ago there could be big problems. Contrary to the predictions oxygen-18 in ancient samples revealed only a little more than in modern oceans.
The authors attribute this to the fact that today a significant part heavy molecules appear in the pores of clay rocks of land. therefore the excess of oxygen-18 can be explained by the fact that there are about 3.24 of them A billion years ago practically did not exist. “Nothing is not contrary to having small individual “microcontinent,” says Wing. – We just don’t think that at that such a global formation of land soils could take place, as today”.
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Australia Water Time Life Climate
