Lithologic Controls on Silicate Weathering Regimes of Temperate Planets

Abstract Weathering of silicate rocks at a planetary surface can draw down CO 2 from the atmosphere for eventual burial and long-term storage in interior. This process is thought to provide essential negative feedback carbonate-silicate cycle (carbon cycle) maintain clement climates on Earth potentially similar temperate exoplanets. We implement thermodynamics determine weathering rates as function lithology (rock type). These upper limits that allow maximum rate regulating climate be estimated. modeling shows mineral assemblages given rock, rather than individual minerals, crucial surfaces. By implementing fluid-transport-controlled approach, we further mimic chemical kinetics three types inspired by lithologies Earth's continental oceanic crust, its mantle. find thermodynamic crust-like are about one two orders magnitude lower those characteristic crust. show when partial pressure decreases or temperature increases, exerts strong control weathering. The kinetically thermodynamically limited regimes depend lithology, whereas supply-limited independent lithology. Our results imply sensitivity may instigate positive carbon cycle, which increases.