Chemical composition of a manganese nodule sample from the MN7601-PLEIADES campaign (R/V Melville)

The authors have selected for analysis a manganese nodule from Station 20 of the PLEIADES Mn7601 campaign. This "apple" shaped nodule (6.5x3.0 cm) was laying on a bed of siliceous ooze (see illustrations). Successive thin layers of the nodule were carefully scraped from the surface of the measured area with a sharp surgical blade. All samples reduced to powder were air-dried at 110°C for at least two hours before analysis. The chemical composition of (1) the top 3-5 mm, (2) the bottom 3-5 mm, and (3) the bulk nodule from a section of Mn7601-20-2 adjacent to the portion used for the radiochemical studies was determined by atomic absorption and neutron activation analysis.

研究人员选取PLEIADES Mn7601科考航次20号站位的一块锰结核（manganese nodule）开展分析，该结核呈苹果状，尺寸为6.5×3.0厘米，赋存于硅质软泥（siliceous ooze）床层之上，详见附图。研究人员使用锋利的手术刀片，从该结核待测取样区域的表面小心刮取其连续薄层样品；所有研磨为粉末的样品均在110℃下空气干燥至少两小时，方可用于后续分析。本次分析测定了三类样品的化学成分，分别为结核表层3~5mm部分、结核底层3~5mm部分，以及Mn7601-20-2切片中与放射化学研究所用样品相邻的整块结核，测试方法采用原子吸收法（atomic absorption）与中子活化分析（neutron activation analysis）。