High-resolution geophysical core logging data from marine sediment core samples

Bottom sediment core samples passed through a non-destructive, automated core logging apparatus are analyzed for their geophysical properties. Compressional (p-wave) velocity, wet bulk density (via gamma attenuation method), and magnetic susceptibility measured in unsplit cores are compared to bulk sediment physical properties, engineering properties, and mineralogy. Generally, silty clays and clays have an average sound velocity of 1500 m/s and average wet bulk density of 1.7 g/cc; coarser sediments, including sand, clayey sand, and sand-silt-clay have an average sound velocity of 1600 m/s and average wet bulk density of 2.0 g/cc. Sediment water content seems to affect both sound velocity and wet bulk density independent of grain size. Magnetic susceptibility (MS) measurements were taken on 43 cores. The MS data are varied due to the presence and concentration of iron-bearing minerals within the bulk sediment sample. Sediments containing terrigenous material (i.e., fluvial deposits containing igneous and metamorphic rock fragments) tend to have a high magnetic susceptibility response (50-150 Sl units); conversely, sediments that contain large amounts of biogenic material (i.e., calcareous marl) usually have a low magnetic susceptibility response (<50 SI units). This information makes possible down-core correlation of the stratigraphic units within a group of adjacent cores. Careful analysis of mass physical properties in conjunction with geophysical parameters may enable geoscientists to predict (model) sea-floor characteristics more accurately.