The vermiculite is a mineral that is almost the same as the earth itself. It is a recorder of time and a chemical window that understands many geological phenomena (such as oxidation).By determining the oxidation level of the magma of these debris, scientists can infer the beginning time of the crust to the mantle cycle, weathering and overshide circulation.Source: China Science Press

The vermiculite is a mineral that is almost as ancient as the earth itself. When the magma (lava) is cooled, crystals can be found in the magma rock.The formation of magma constitutes the mountains on the earth.By interaction with water and atmosphere, the mountains are decomposed into sediments.

The vermiculite is strong and stable. It is resistant to wind and erosion, and rarely disappears in history. Therefore, the minerals in the sediment (so -called “dandruff gangsters”) can most let people understand the past of the earth.The vermiculite is rich in uranium (U-PB measurement method). It is a recorder of time and a chemical window for many geological phenomena (such as oxidation).

The average value of the ΔFMQ movement of the ΔFMQ of the firestone and the sedimentary material vermiculite (the proportion of less than 10%) is the time interval between the supercalloscope.The magma related to the sedimentary source is more reduced in the cyclicality of about 600mA and formed at 2.6 billion years.Source: China Science Press

The research team uses a new method of Loucks et al. (2020) to determine the oxidation state of granite magma. This method uses the ratio of CE, U, and TI in vermiculite to track the oxidation changes in the history of crustal magma in the history of the earth.The calculation method does not need to know ion charge, nor does it need to determine the crystalline temperature, pressure or mother melt ingredient.

“The previous methods include CE/CE*and EU/EU*oxygen pressure meters, but each method has the changes in temperature, pressure, main rock chemical composition or measurement of the Ree required by the CE/CE*and EU/EU*abnormalities.Limitation of element accuracy “.Bob Loucks from Western Australia said.

This improved oxidation meter can more reliable to evaluate changes in the state of oxidation. Now it can explain changes in the state of oxidation from the perspective of global structure.By determining the oxidation level of the magma of these debris, scientists can infer the beginning time of the crust to the mantle cycle, weathering and overshide circulation.

The key point is that the rocks located on the surface of the earth can be brought back to the depths of the mantle (hundreds to thousands of kilometers below the surface).Our data show that this phenomenon not only happened today, but also may have lasted billions of years.By observing the vermiculite formed from the early Earth and 3 billion years ago to the vermiculite formed today, we found that the magma oxidation and restoration status when they were formed.

The oxidation state (represented by ΔFMQ) of the dandruff has increased by about 3.5 billion years ago, and then the average ΔFMQ> 0> 0 in the past 3 billion years indicates that the large ocean rock ring has been recovered back to the mantle in the final dive zone.Studies have shown that the lower limit of oxidation and rewarding has dropped sharply 2.6 billion years ago, marking the formation of well -bounded continents and the large ocean rocks buried back to the deep mantle of the earth.In addition, the researchers have also discovered the periodicity of the oxidation reduction model: every 600 million years, the mainland will gather together to form a super continent, such as Ggana continent, Rodinia continent, Nura continent, and Supil.Mainland China.