Structural transitions of calcium carbonates in the lower mantle

Metal carbonates MCO3 (M=Ca,Mg,Fe,Sr) are among of the most common minerals and contain ≈ 60–70% of the inorganic carbon present on Earth’s surface and in its crust[1]. Carbonates play important role in the deep-carbon-cycle as they are the responsible for transferring carbon from the Earth’s oceanic crust to the mantle via subduction. In continuation of our previous experiments on mineral physics and chemistry of the CaCxOy at conditions of the Earth lower mantle, we propose to perform in situ powder and single-crystal multi-grain X-ray diffraction (SCXRD) at pressures of 60-140 GPa and temperatures 2600-3500 K, in order to complete information about phases and phase relations in the Ca-C-O system to the depth corresponding of core-mantel boundary.