Related Experiment Video
Updated: Jun 3, 2026
10:18
Dynamic Pore-scale Reservoir-condition Imaging of Reaction in Carbonates Using Synchrotron Fast Tomography
Published on: February 21, 2017
New host for carbon in the deep Earth.
Eglantine Boulard1, Alexandre Gloter, Alexandre Corgne
1Unité Mixte de Recherche Centre National de la Recherche Scientifique 7590, Institut de Minéralogie et de Physique des Milieux Condensés, Université Pierre et Marie Curie,75005 Paris, France. boulard@impmc.jussieu.fr
Summary
Scientists discovered a new carbon-bearing mineral deep within Earth
Area of Science:
- Geochemistry
- Mineralogy
- High-pressure geophysics
Background:
- The global carbon cycle involves exchanges between Earth's interior and surface.
- Understanding carbon's fate in the mantle is crucial for global carbon cycle dynamics.
- Carbon is subducted into the mantle as carbonates and released via volcanism as CO(2).
Purpose of the Study:
- To investigate the thermodynamic properties and phase diagrams of minerals under core mantle boundary conditions.
- To clarify the nature of carbon-bearing minerals at extreme depths.
- To understand the stability of carbonates versus decarbonation and melting.
Main Methods:
- First principles quantum calculations were used to predict mineral structures.
- Experimental investigations were conducted at pressures simulating depths greater than 1,800 km.
- Analysis of mineral assemblages including new high-pressure phases, magnetite, and nanodiamonds.
Main Results:
- A novel Mg-Fe carbon-bearing compound was identified at depths exceeding 1,800 km.
- The compound's structure features three-membered rings of corner-sharing (CO(4))(4-) tetrahedra.
- This high-pressure polymorph concentrates Fe((III)) through an intracrystalline reaction.
Conclusions:
- The discovery of this new phase advances our understanding of deep Earth carbon speciation.
- The findings provide critical data for modeling the geochemical carbon cycle.
- The research highlights the complex interplay of pressure, temperature, and composition on mineral stability in the lower mantle.
More Related Videos
Related Concept Videos
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
01:14The Carbon Cycle
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
01:28Carbon-dioxide Fixation
Carbon dioxide fixation in prokaryotes enables the assimilation of inorganic carbon into organic molecules, supporting biosynthetic pathways, sustaining ecosystems, and contributing to the global carbon cycle. It also has industrial applications in carbon capture and bioproduct synthesis. Autotrophic organisms rely on this process to utilize CO₂ as a carbon source in diverse environments.The Calvin CycleThe Calvin cycle is the most widespread carbon fixation mechanism, primarily used by...
01:12Carbon Skeletons
Life on Earth is carbon-based, as all macromolecules that make up living organisms contain carbon atoms. All organic compounds have a carbon backbone. Each carbon atom is tetravalent and can bond with four other atoms, making it an extraordinarily flexible component of biological molecules. Because carbon’s valence electrons are stable, it rarely becomes an ion. As the carbon chain increases in length, structural modifications such as ring structures, double bonds, and branching side chains...
01:24Microbes and the Carbon Cycle
The carbon cycle is a fundamental Earth process involving the transfer of carbon among the biosphere, lithosphere, atmosphere, and hydrosphere. It plays a critical role in regulating the planet’s climate and supporting life by cycling carbon through various chemical forms and reservoirs. Carbon primarily circulates as carbon dioxide (CO₂), representing its oxidized form, while reduced forms such as methane (CH₄) and organic compounds also play essential roles.Microbial activity is central to...
01:26Microbes and Methanogenesis
Methanogenesis is a critical microbial process in anaerobic ecosystems responsible for the biological production of methane, a potent greenhouse gas and valuable biofuel. This metabolic pathway is primarily facilitated by methanogenic archaea, which thrive in anoxic environments such as wetlands, sediments, and animal gastrointestinal tracts. The absence of oxygen in these habitats prevents aerobic respiration, thereby favoring alternative biochemical pathways for organic matter degradation.In...