The primitive oceans have very hot temperatures!

According to a French study published in Nature that confirms a controversial hypothesis for 30 years: 2 to 3.5 billion years ago, the average temperature in the oceans could reach 80 ^o. C and has diminished after millennia to allow life to grow and be diversified.

By analyzing the oxygen and silicon isotope composition in sedimentary rocks very close to the igneous rock from 3.5 billion years, two researchers Marc Chaussidon (Center for Petrography and geochemistry) and François Robert (National Museum of Natural History) measured the temperature of pre-Cambrian oceans.

The first studies done in the 70s based on oxygen isotopes had been confirmed at the time that the oceans were very hot. But these results were not approved. It is known that 4 billion years ago, the Sun was not as bright as it is today, causing the Earth to be cold.

Two French researchers compared oxygen and silicon isotopes in ancient sedimentary rocks. The results confirmed that the ocean used to be very hot 3.5 billion years ago and cooled to 30oC 800 million years ago.

This colder phenomenon is very convenient for living organisms to begin to proliferate in the oceans. The higher the temperature, the less dissolved oxygen is in water. Complex multicellular organisms are known to need oxygen to grow.

VN