Mean grain-size and sorting of sediments from the Piedra Buena contourite terrace

The dataset contains results of grain-size analyses of sediments after removing the biogenic calcium carbonate, the biogenic opal and organics. Grain-size analyses were performed using a SALD-2300 laser diffraction particle size analyzer (Shimadzu, Japan), which yields a size spectrum from 17 nm to 2.5 mm. Grain-size analysis was performed both on the bulk sediment samples and calcium carbonate-free samples. Hydrochloric acid (10%) was used to remove biogenic calcium carbonate. For core AI-3442, where the radiolarian content is relatively high compared to the rest of the cores, the biogenic opal was removed using 1M sodium hydroxide solution (NaOH). H2O2 was used to remove organics. Sodium hexametaphosphate solution (Na6P6O18, 0.7%) and ultrasonication (1 min) were applied to all the studied samples for particle disaggregation. Mean grain size and sorting coefficient were calculated according to Folk and Ward (1957) using the GRADISTAT software (Blott and Pye, 2001).本数据集包含去除生物成因碳酸钙（biogenic calcium carbonate）、生物成因蛋白石（biogenic opal）及有机质后的沉积物粒度分析结果。本次粒度分析采用日本岛津（Shimadzu）生产的SALD-2300型激光衍射粒度分析仪，其可检测的粒径范围为17 nm至2.5 mm。粒度分析分别针对全沉积物样品及脱碳酸钙样品开展。实验采用10%盐酸去除生物成因碳酸钙。相较于其余岩芯，AI-3442岩芯的放射虫含量相对更高，因此采用1 mol/L氢氧化钠（NaOH）溶液去除其生物成因蛋白石。使用过氧化氢（H₂O₂）去除样品中的有机质。向所有研究样品中加入0.7%六偏磷酸钠（Na₆P₆O₁₈）溶液，并辅以1分钟超声处理以实现颗粒解聚。依据Folk与Ward（1957）提出的方法，借助GRADISTAT软件（Blott与Pye，2001）计算平均粒径及分选系数。