Recent research has suggested that the continental crust of the Earth is much older than before. According to scientists’ calculations, it appeared half a billion years earlier than expected.
Barite as a “time capsule”
Although a small percentage of today’s continental crust is earlier than this time, it appeared several billion years ago. To calculate the age of the continents, researchers are studying the decay of ancient chemical compounds trapped in rocks (usually carbonate minerals recovered from the oceans), but these are found to be particularly rare and sufficient to analyze them. Must be intact from.
As part of the work presented during Virtual Conference of European Geoscience Union 2021A team of researchers developed a new method for dating ancient fragments of the earth’s crust, including the analysis of a mineral called barite, which is a combination of marine salts and barium.
Dense minerals are formed at depths, where warm, nutrient-rich water originates from hydrothermal vents, which touch the ocean floor. According to the researchers, they have the distinction of preserving traces of nutrient exchange between continents and oceans.
The major process here is bloat. When continents naturally degrade over time, they release nutrients into the nearby sea. A study published in the journal on 11 February Science Showed that when the continental crust of our planet stopped growing over the course of about one billion years ” middle age From ” TerreThe development of life suddenly slowed down.
A continental crust is older than expected
One of the elements releasing continental crust in the ocean is strontium. By measuring the proportion of its two isotopes in six different barite deposits, researchers were able to calculate the age of these minerals, which ranged from 3.2 to 3.5 billion years. But the story does not end there. From these minerals, the team also decided how long it had remained since ancient continents began to release strontium into the oceans, where these barytes had formed.
Analyzes conducted have shown that this process of continental change began about 3.7 billion years ago, suggesting the formation of continents 500 million years earlier than previous estimates, and means that processes such as plate tectonics are part of our Are already involved on the planet. At least that long.
Although further research will be needed to confirm this, researchers believe that it may also have an impact on the development of ocean life, as these continental nutrients evolve.