Two‐ and three‐dimensional heterogeneity in carbonate sediments using resistivity imaging

Improving the characterization of buried inhomogeneities will lead to better models for predicting bottom acoustic backscattering. Sediment volume heterogeneity has been investigated using fine scale electrical resistivity data which is sensitive to porosity and sediment structure, both macro and micro. 3D electrical resistivity experiments are described where a 2D network of resistivity electrodes was used on the surface of freshly collected box cores from the Dry Tortugas, Key West. The resulting 3D resistivity data provides a unique insight into the spatial variability of sediment porosity and structure at the cm scale. Complementary X‐radiograph cores provided 2D datasets of resistivity and porosity, at higher resolution. They have been used to establish the porosity‐resistivity‐microstructure relationships for these carbonate sediments, with microstructure being described in terms of tortuosity. These relationships have been used to extend our interpretation in terms of porosity and tortuosity to the...