Related Experiment Video
Updated: Oct 28, 2025

Monitoring Pedogenic Inorganic Carbon Accumulation Due to Weathering of Amended Silicate Minerals in Agricultural Soils.
Published on: June 4, 2021
Deep carbon cycle constrained by carbonate solubility
Stefan Farsang1, Marion Louvel2, Chaoshuai Zhao3
1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK. sf571@cam.ac.uk.
Abstract:
Earth's deep carbon cycle affects atmospheric CO2, climate, and habitability. Owing to the extreme solubility of CaCO3, aqueous fluids released from the subducting slab could extract all carbon from the slab. However, recycling efficiency is estimated at only around 40%. Data from carbonate inclusions, petrology, and Mg isotope systematics indicate Ca2+ in carbonates is replaced by Mg2+ and other cations during subduction. Here we determined the solubility of dolomite [CaMg(CO3)2] and rhodochrosite (MnCO3), and put an upper limit on that of magnesite (MgCO3) under subduction zone conditions. Solubility decreases at least two orders of magnitude as carbonates become Mg-rich. This decreased solubility, coupled with heterogeneity of carbon and water subduction, may explain discrepancies in carbon recycling estimates. Over a range of slab settings, we find aqueous dissolution responsible for mobilizing 10 to 92% of slab carbon. Globally, aqueous fluids mobilise [Formula: see text]% ([Formula: see text] Mt/yr) of subducted carbon from subducting slabs.
More Related Videos
Related Concept Videos
The Carbon Cycle
Solubility Equilibria
The...
Factors Affecting Solubility
Carbon-dioxide Fixation
Carbon Dioxide Transport in the Blood
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Phase Diagrams

