Figure F56. Crossplots of (A) shallow resistivity vs. compressional wave velocity and (B) density vs. porosity. The basalts in the igneous basement generally show the highest densities, resistivities, compressional wave velocities, and the lowest porosities. Sediments of lithologic basement Unit I (see "Lithostratigraphy") exhibit low density, low resistivity, low velocity, and high porosity values, and are therefore distinct from the crystalline rocks. Sediments interbedded with pillow basalts show intermediate physical property values; however, the fields overlap and are not clearly distinguished.