Fluid flow and hydration in oceanic lithosphere: Insights from theory and numerical investigation

The oceanic mantle lithosphere has considerable potential to store chemically bound water, thereby being an important factor for the deep water cycle. However, the actual extent of hydrous alteration in such mantle rocks is debated. Geodynamic modeling has the potential to directly predict the extent of fluid flow through oceanic lithosphere, and, in turn, the extent of serpentinization. By comparing theory and numerical simulations, we demonstrate that conventional geodynamic models are inherently inconsistent with the physics of brittle deformation, and, as a result, they overestimate the extent of fluid flow during extension. In contrast to the extensive serpentinization often inferred with bending-related processes during subduction, limited serpentinization is consistent with theoretical predictions and geophysical observations.