Volatile-consuming reactions fracture rocks and self-accelerate fluid flow in the lithosphere

Abstract

Significance Hydration and carbonation are the main reactions that drive volatile cycles in the Earth. These reactions are characterized by a large increase in solid volume, by up to several tens of percent, and may induce fracturing, fluid flow, and further reactions. However, no experimental studies have succeeded in a clear increase in fluid flow during the reactions, and the mechanisms that control acceleration or deceleration remain largely unknown. We present here clear experimental evidence that hydration reactions can fracture rocks and accelerate fluid flow, under confining pressure (i.e., at simulated depth). We conclude that a high reaction rate, relative to the fluid flow rate, is essential for fracturing and accelerated fluid flow during these reactions in the Earth.