This dataset includes two procedures: grain-size measurements and modern (rose-bengal stained) benthic foraminifera census offshore Thwaites Glacier. Sediment underwent staining with a rose-bengal ethanol solution for a minimum of 24 hours. Subsequently, the samples were dried, split, and identified for the foraminifera census. Grain-size measurements were conducted on approximately five cubic centimeters of a duplicate Multicore. Thesamples were dispersed using a sodium hexametaphosphate solution for at least 24 hours before being analyzed with a Cilas 1190 laser particle size analyzer. The grain size is reported based on the diameter at which a certain percentage of grains are coarser. For instance, the D90 measurement signifies the diameter at which 90% of grains are coarser.