AUTHOR=Kellogg Louise H. , Turcotte Donald L. , Lokavarapu Harsha TITLE=On the Role of the Urey Reaction in Extracting Carbon From the Earth's Atmosphere and Adding It to the Continental Crust JOURNAL=Frontiers in Astronomy and Space Sciences VOLUME=6 YEAR=2019 URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2019.00062 DOI=10.3389/fspas.2019.00062 ISSN=2296-987X ABSTRACT=

Urey (1952a,b, 1956) introduced the Urey reaction to explain the origin of carbonates in the continental crust. The reaction extracts CO₂ from the atmosphere in acid rain that reacts with calcium silicates, the products are transported to the oceans where organic and inorganic processes results in the deposition of calcium carbonates. The origin of the CO₂ can be (1) the early atmosphere and (2) the mantle. The reaction removes almost all the atmospheric CO₂ that survived the formation of the Earth. If surface volcanism introduces more CO₂ than is lost by subduction, the CO₂ entering the atmosphere will be lost to the continental crust by the Urey reaction. Studies of carbon fluxes between surface reservoirs have demonstrated the importance of the Urey reaction in controlling the concentration of CO₂ in the atmosphere. At the present time the only surface reservoir with a large mass of carbon is the continental crust. In order to quantify the rate at which the Urey reaction removes CO₂ from the atmosphere we utilize data from the Paleocene-Eocene thermal maximum (PETM). This was a period of elevated global temperatures (ΔT = 4 − 5°C) at 56 Ma attributed to a pulse of volcanism and associated CO₂ in the north Atlantic. We utilize the decay time of this thermal anomaly to quantify the rate at which CO₂ is extracted from the atmosphere by the Urey reaction.