Résumé
During Integrated Ocean Drilling Program Expedition 313 on the New Jersey shallow shelf, sandy shallow-marine late Eocene to middle Miocene sediments were successfully drilled at three sites (M0027, M0028, and M0029). From the upper unconsolidated intervals, approximately 634 m thick overall, a total of 275 sediment samples were analyzed for grain-size distributions. Average (arithmetic mean) grain size ranges from fine silt to coarse sand, passing from medium silt to medium sand because of the limited occurrence of coarse silt and fine sand. Silty sediments dominate overall, and clay-dominated sediments were not recognized. Average grain-size data plotted on the equivalent intervals of geologic columnar sections show that stratigraphic changes concordantly reflect lithology and sequence stratigraphy at all three sites. Grain-size frequency curves of measured sediment samples can be divided into 16 silt and 8 sand sediment types on the basis of shape, mode position, grain size range, and volume of skewed coarser or finer grain components. Lithostratigraphic changes are concordant to average grain-size curves and sequence stratigraphy, in general.