Luray Caverns does not date beyond the Tertiary period. The cave is developed in dolomites of the lower Beekmantown Dolomite (Lower Ordovician). At some period, niches and already formed chambers were completely filled with water, highly charged with acid, which then slowly began to eat away at much of the softer material composing much of the walls, ceilings and floors. The one particular area that shows this high level of water is Elfin Ramble where water marks of oscillation are highly visible on the ceiling.