New High‐Pressure Phase of CaCO3 at the Topmost Lower Mantle: Implication for the Deep‐Mantle Carbon Transportation

• Published in: Geophysical research letters Vol. 45; no. 3; pp. 1355 - 1360
• Main Authors: Li, Xinyang, Zhang, Zhigang, Lin, Jung‐Fu, Ni, Huaiwei, Prakapenka, Vitali B., Mao, Zhu
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 16.02.2018; American Geophysical Union; Wiley
• Subjects: Aragonite; CaCO3‐SiO2 reaction; CaCO3‐VII; Calcium carbonate; Carbon; carbon transportation; Diamond anvil cells; Diamonds; GEOSCIENCES; High pressure; high pressure‐temperature; Laser beam heating; Lasers; Lower mantle; Mantle; Oceanic crust; Silica; Silicon dioxide; Stability; Stishovite; topmost lower mantle

In this study, we have investigated the stability of CaCO3 at high pressures and temperatures using synchrotron X‐ray diffraction in laser‐heated diamond anvil cells. Our experimental results have shown that CaCO3 in the aragonite structure transforms into CaCO3‐VII (P21/c) at 27 GPa and 1,500 K wit...