Hydro-mechanical characterization of calcium carbonate concretions

Abstract

We investigated the hydraulic and mechanical properties of spherical calcium carbonate concretions and their surrounding matrices in a Neogene accretionary deposit in the Hayama Group (Kanagawa prefecture) and a brackish to marine formation in the Mizunami Group. The concretions in both formations have lower permeabilities and porosities and greater hardness than the surrounding host rocks. Although the concretions in both formations were formed in different depositional environments, they hardened a short time after the death of a living organism. This means that they can be considered stable over long periods and would not be significantly affected by subsequent deformation and tectonic events. This property is useful for engineering applications, as it would yield a long-lasting seal.