Wormhole, Peniche

3D Model

Dissolved calcareous rock, Peniche, Portugal. Wormholes are dissolution features forming slowly during flow in joints: slightly acidic water dissolves calcites. In proper conditions of fast enough flow in fine enough initially quasiplanar open fractures (joints), cylindrical-like channels develop, carving the planar boundaries. These features, related to a natural instability, are known as wormholes.