000006834 001__ 6834
000006834 005__ 20240217112633.0
000006834 0247_ $$2DOI$$a10.3847/PSJ/abe1b8
000006834 037__ $$aSCART-2024-0090
000006834 100__ $$aHakim, Kaustubh
000006834 245__ $$aLithologic Controls on Silicate Weathering Regimes of Temperate Planets
000006834 260__ $$c2021
000006834 520__ $$aWeathering of silicate rocks at a planetary surface can draw down CO2 from the atmosphere for eventual burial and long-term storage in the planetary interior. This process is thought to provide essential negative feedback to the carbonate-silicate cycle (carbon cycle) to maintain clement climates on Earth and potentially similar temperate exoplanets. We implement thermodynamics to determine weathering rates as a function of surface lithology (rock type). These rates provide upper limits that allow the maximum rate of weathering in regulating climate to be estimated. This modeling shows that the weathering of mineral assemblages in a given rock, rather than individual minerals, is crucial to determine weathering rates at planetary surfaces. By implementing a fluid-transport-controlled approach, we further mimic chemical kinetics and thermodynamics to determine weathering rates for three types of rocks inspired by the lithologies of Earth's continental and oceanic crust, and its upper mantle. We find that thermodynamic weathering rates of a continental crust-like lithology are about one to two orders of magnitude lower than those of a lithology characteristic of the oceanic crust. We show that when the CO2 partial pressure decreases or surface temperature increases, thermodynamics rather than kinetics exerts a strong control on weathering. The kinetically and thermodynamically limited regimes of weathering depend on lithology, whereas the supply-limited weathering is independent of lithology. Our results imply that the temperature sensitivity of thermodynamically limited silicate weathering may instigate a positive feedback to the carbon cycle, in which the weathering rate decreases as the surface temperature increases.
000006834 594__ $$aNO
000006834 700__ $$aBower, Dan J.
000006834 700__ $$aTian, Meng
000006834 700__ $$aDeitrick, Russell
000006834 700__ $$aAuclair-Desrotour, Pierre
000006834 700__ $$aKitzmann, Daniel
000006834 700__ $$aDorn, Caroline
000006834 700__ $$aMezger, Klaus
000006834 700__ $$aHeng, Kevin
000006834 773__ $$c29$$n2$$pPlanetary Science Journal$$v2$$y2021
000006834 8560_ $$fkaustubh.hakim@ksb-orb.be
000006834 85642 $$ahttps://doi.org/10.3847/PSJ/abe1b8
000006834 8564_ $$s3324636$$uhttp://publi2-as.oma.be/record/6834/files/Hakim_2021_Planet._Sci._J._2_49.pdf
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000006834 905__ $$apublished in
000006834 980__ $$aREFERD