Examining conditions within the Earth’s interior is crucial not only to give us a window back to Earth’s history but also to understand the current environment and its future. This study offers an explanation of carbon’s descent into the deep Earth. “The stability regions of carbonates are key to understanding the deep carbon cycle and the role of the deep Earth in the global carbon cycle.” says Leonid Dubrovinsky, from the University of Bayreuth. “The intense X-rays from the ESRF allow us to access the extreme conditions within the entire Earth’s mantle.” underlines Valerio Cerantola, lead author, former PhD student at the University of Bayreuth and now postdoctoral scientist at the ESRF.
Examining conditions within the Earth’s interior is crucial not only to give us a window back to Earth’s history but also to understand the current environment and its future. This study offers an explanation of carbon’s descent into the deep Earth. “The stability regions of carbonates are key to understanding the deep carbon cycle and the role of the deep Earth in the global carbon cycle.” says Leonid Dubrovinsky, from the University of Bayreuth. “The intense X-rays from the ESRF allow us to access the extreme conditions within the entire Earth’s mantle.” underlines Valerio Cerantola, lead author, former PhD student at the University of Bayreuth and now postdoctoral scientist at the ESRF.
In the last century, the rapid increase in the amount of CO2 in the atmosphere together with the observed climate change have increasingly focused scientists’ attention on the carbon cycle and its evolution at the Earth’s surface. The carbon cycle also extends below the surface: recent estimations locate up to 90% of the Earth’s carbon budget in the Earth’s mantle and core. Due to the dynamic nature of tectonic plate movements, convection and subduction, there is a constant recycling of carbon between the Earth’s surface and its deep interior.
In this study, the research team focused on carbonate phases, which are one of the main carbon-bearing minerals in the deep mantle. Carbonates are a group of minerals that contain the carbonate ion (CO32-) and a metal, such as iron or magnesium. The scientists studied the behaviour of a pure iron carbonate, FeCO3 (called siderite), at extreme temperature and pressure conditions covering the entire Earth’s mantle, meaning over 2500 K and 100 GPa, which corresponds to roughly one million times the atmospheric pressure.
Read more at The European Synchrotron Radiation Facility
Image: Valerio Cerantola, corresponding author and postdoctoral scientist at the ESRF, at ESRF ID27 high pressure beamline. (Credit: ESRF)
