Biogenic silica at IODP Site U1475 during the early Pliocene

This dataset provides the early Pliocene biogenic silica (BSi) concentrations from IODP Site U1475, drilled on the southwestern flank of the Agulhas Plateau in the southwestern Indian Ocean during IODP Expedition 361: South African Climate (30 January to 31 March 2016). BSi weight percent (wt. %) was measured for 74 samples using a modified Mortlock and Froelich (1989) method. Each sample, approximately 55 mg, was freeze-dried and processed to remove organic matter and carbonates with 30% hydrogen peroxide and 1-M hydrochloric acid. Following this preparation, the samples were treated with 10% sodium carbonate and heated at 80°C for 5 hours to break down the opal content. BSi concentration was then quantified using a molybdate-blue spectrophotometer, calibrated with standards ranging from 0 to 50 ppm.本数据集收录了西南印度洋厄加勒斯海台西南侧翼钻探获取的上新世早期生物成因二氧化硅（biogenic silica, BSi）浓度数据，该样品采自国际大洋发现计划（International Ocean Discovery Program, IODP）第361次科考航次“南非气候”（2016年1月30日至3月31日）所钻探的U1475站位。研究人员采用经改良的Mortlock与Froelich（1989）方法，对74个样品的BSi质量百分比（weight percent, wt. %）开展了测定。每个样品重量约为55毫克，经冷冻干燥后，使用30%过氧化氢与1摩尔每升盐酸去除其中的有机质与碳酸盐。完成上述前处理流程后，样品经10%碳酸钠溶液处理，并在80℃条件下加热5小时以分解蛋白石组分。随后借助钼蓝分光光度计对BSi浓度进行定量分析，以浓度范围为0至50ppm的标准溶液完成校准。